render.py

# SPDX-License-Identifier: GPL-2.0-or-later

# <pep8 compliant>

"""Write the POV file using this file's functions and some from other modules then render it."""

import bpy
import subprocess
import os
from sys import platform
import time
from math import (
    pi,
)  # maybe move to scenography.py and topology_*****_data.py respectively with smoke and matrix

import re
import tempfile  # generate temporary files with random names
from bpy.types import Operator
from bpy.utils import register_class, unregister_class

from . import (
    scripting,
)  # for writing, importing and rendering directly POV Scene Description Language items
from . import scenography  # for atmosphere, environment, effects, lighting, camera
from . import shading  # for BI POV shaders emulation
from . import object_mesh_topology  # for mesh based geometry
from . import object_curve_topology  # for curves based geometry

# from . import object_primitives  # for import and export of POV specific primitives


from .scenography import image_format, img_map, img_map_transforms, path_image

from .shading import write_object_material_interior
from .object_primitives import write_object_modifiers


def string_strip_hyphen(name):

    """Remove hyphen characters from a string to avoid POV errors."""

    return name.replace("-", "")


def safety(name, ref_level_bound):
    """append suffix characters to names of various material declinations.

    Material declinations are necessary to POV syntax and used in shading.py
    by the pov_has_no_specular_maps function to create the finish map trick and
    the suffixes avoid name collisions.
    Keyword arguments:
    name -- the initial material name as a string
    ref_level_bound -- the enum number of the ref_level_bound being written:
        ref_level_bound=1 is for texture with No specular nor Mirror reflection
        ref_level_bound=2 is for texture with translation of spec and mir levels
        for when no map influences them
        ref_level_bound=3 is for texture with Maximum Spec and Mirror
    """
    # All the try except clause below seems useless as each time
    # prefix rewritten even after and outside of it what was the point?
    # It may not even be any longer possible to feed no arg from Blender UI
    # try:
    # if name: # if int(name) > 0: # could be zero if no argument provided
    # # and always triggered exception so is this similar ?
    # prefix = "shader"
    # except BaseException as e:
    # print(e.__doc__)
    # print('An exception occurred: {}'.format(e))
    # prefix = "" # rewritten below...
    prefix = "shader_"
    name = string_strip_hyphen(name)
    if ref_level_bound == 2:
        return prefix + name
    # implicit else-if (no return yet)
    if ref_level_bound == 1:
        return prefix + name + "0"  # used for 0 of specular map
    # implicit else-if (no return yet)
    if ref_level_bound == 3:
        return prefix + name + "1"  # used for 1 of specular map


# -------- end safety string name material


csg_list = []


def is_renderable(ob):
    """test for objects flagged as hidden or boolean operands not to render"""
    return not ob.hide_render and ob not in csg_list


def renderable_objects():
    """test for non hidden, non boolean operands objects to render"""
    return [ob for ob in bpy.data.objects if is_renderable(ob)]


def no_renderable_objects():
    """Boolean operands only. Not to render"""
    return list(csg_list)


tab_level = 0
unpacked_images = []

user_dir = bpy.utils.resource_path('USER')
preview_dir = os.path.join(user_dir, "preview")

# Make sure Preview directory exists and is empty
smoke_path = os.path.join(preview_dir, "smoke.df3")

'''

# below properties not added to __init__ yet to avoid conflicts with material sss scale
# unless it would override then should be interfaced also in scene units property tab

# if scene.pov.sslt_enable:
    # file.write("    mm_per_unit %s\n"%scene.pov.mm_per_unit)
    # file.write("    subsurface {\n")
    # file.write("        samples %s, %s\n"%(scene.pov.sslt_samples_max,scene.pov.sslt_samples_min))
    # if scene.pov.sslt_radiosity:
        # file.write("        radiosity on\n")
    # file.write("}\n")

'''


# def write_object_modifiers(ob, File):
# """Translate some object level POV statements from Blender UI
# to POV syntax and write to exported file """

# # Maybe return that string to be added instead of directly written.

# '''XXX WIP
# import .object_mesh_topology.write_object_csg_inside_vector
# write_object_csg_inside_vector(ob, file)
# '''

# if ob.pov.hollow:
# File.write("\thollow\n")
# if ob.pov.double_illuminate:
# File.write("\tdouble_illuminate\n")
# if ob.pov.sturm:
# File.write("\tsturm\n")
# if ob.pov.no_shadow:
# File.write("\tno_shadow\n")
# if ob.pov.no_image:
# File.write("\tno_image\n")
# if ob.pov.no_reflection:
# File.write("\tno_reflection\n")
# if ob.pov.no_radiosity:
# File.write("\tno_radiosity\n")
# if ob.pov.inverse:
# File.write("\tinverse\n")
# if ob.pov.hierarchy:
# File.write("\thierarchy\n")

# # XXX, Commented definitions
# '''
# if scene.pov.photon_enable:
# File.write("photons {\n")
# if ob.pov.target:
# File.write("target %.4g\n"%ob.pov.target_value)
# if ob.pov.refraction:
# File.write("refraction on\n")
# if ob.pov.reflection:
# File.write("reflection on\n")
# if ob.pov.pass_through:
# File.write("pass_through\n")
# File.write("}\n")
# if ob.pov.object_ior > 1:
# File.write("interior {\n")
# File.write("ior %.4g\n"%ob.pov.object_ior)
# if scene.pov.photon_enable and ob.pov.target and ob.pov.refraction and ob.pov.dispersion:
# File.write("ior %.4g\n"%ob.pov.dispersion_value)
# File.write("ior %s\n"%ob.pov.dispersion_samples)
# if scene.pov.photon_enable == False:
# File.write("caustics %.4g\n"%ob.pov.fake_caustics_power)
# '''


def write_pov(filename, scene=None, info_callback=None):
    """Main export process from Blender UI to POV syntax and write to exported file """

    import mathutils

    with open(filename, "w") as file:
        # Only for testing
        if not scene:
            scene = bpy.data.scenes[0]

        render = scene.render
        world = scene.world
        global_matrix = mathutils.Matrix.Rotation(-pi / 2.0, 4, 'X')
        comments = scene.pov.comments_enable and not scene.pov.tempfiles_enable
        linebreaksinlists = scene.pov.list_lf_enable and not scene.pov.tempfiles_enable
        feature_set = bpy.context.preferences.addons[__package__].preferences.branch_feature_set_povray
        using_uberpov = feature_set == 'uberpov'
        pov_binary = PovrayRender._locate_binary()

        if using_uberpov:
            print("Unofficial UberPOV feature set chosen in preferences")
        else:
            print("Official POV-Ray 3.7 feature set chosen in preferences")
        if 'uber' in pov_binary:
            print("The name of the binary suggests you are probably rendering with Uber POV engine")
        else:
            print("The name of the binary suggests you are probably rendering with standard POV engine")

        def set_tab(tabtype, spaces):
            tab_str = ""
            if tabtype == 'NONE':
                tab_str = ""
            elif tabtype == 'TAB':
                tab_str = "\t"
            elif tabtype == 'SPACE':
                tab_str = spaces * " "
            return tab_str

        tab = set_tab(scene.pov.indentation_character, scene.pov.indentation_spaces)
        if not scene.pov.tempfiles_enable:

            def tab_write(str_o):
                """Indent POV syntax from brackets levels and write to exported file """
                global tab_level
                brackets = str_o.count("{") - str_o.count("}") + str_o.count("[") - str_o.count("]")
                if brackets < 0:
                    tab_level = tab_level + brackets
                if tab_level < 0:
                    print("Indentation Warning: tab_level = %s" % tab_level)
                    tab_level = 0
                if tab_level >= 1:
                    file.write("%s" % tab * tab_level)
                file.write(str_o)
                if brackets > 0:
                    tab_level = tab_level + brackets

        else:

            def tab_write(str_o):
                """write directly to exported file if user checked autonamed temp files (faster)."""

                file.write(str_o)

        def unique_name(name, name_seq):
            """Increment any generated POV name that could get identical to avoid collisions"""

            if name not in name_seq:
                name = string_strip_hyphen(name)
                return name

            name_orig = name
            i = 1
            while name in name_seq:
                name = "%s_%.3d" % (name_orig, i)
                i += 1
            name = string_strip_hyphen(name)
            return name

        def write_matrix(matrix):
            """Translate some transform matrix from Blender UI
            to POV syntax and write to exported file """
            tab_write(
                "matrix <%.6f, %.6f, %.6f,  %.6f, %.6f, %.6f,  %.6f, %.6f, %.6f,  %.6f, %.6f, %.6f>\n"
                % (
                    matrix[0][0],
                    matrix[1][0],
                    matrix[2][0],
                    matrix[0][1],
                    matrix[1][1],
                    matrix[2][1],
                    matrix[0][2],
                    matrix[1][2],
                    matrix[2][2],
                    matrix[0][3],
                    matrix[1][3],
                    matrix[2][3],
                )
            )

        material_names_dictionary = {}
        DEF_MAT_NAME = ""  # or "Default"?

        # -----------------------------------------------------------------------------

        def export_meta(metas):
            """write all POV blob primitives and Blender Metas to exported file """
            # TODO - blenders 'motherball' naming is not supported.

            if comments and len(metas) >= 1:
                file.write("//--Blob objects--\n\n")
            # Get groups of metaballs by blender name prefix.
            meta_group = {}
            meta_elems = {}
            for meta_ob in metas:
                prefix = meta_ob.name.split(".")[0]
                if prefix not in meta_group:
                    meta_group[prefix] = meta_ob  # .data.threshold
                elems = [
                    (elem, meta_ob)
                    for elem in meta_ob.data.elements
                    if elem.type in {'BALL', 'ELLIPSOID', 'CAPSULE', 'CUBE', 'PLANE'}
                ]
                if prefix in meta_elems:
                    meta_elems[prefix].extend(elems)
                else:
                    meta_elems[prefix] = elems

                # empty metaball
                if len(elems) == 0:
                    tab_write("\n//dummy sphere to represent empty meta location\n")
                    tab_write(
                        "sphere {<%.6g, %.6g, %.6g>,0 pigment{rgbt 1} "
                        "no_image no_reflection no_radiosity "
                        "photons{pass_through collect off} hollow}\n\n"
                        % (meta_ob.location.x, meta_ob.location.y, meta_ob.location.z)
                    )  # meta_ob.name > povdataname)
                # other metaballs
                else:
                    for mg, mob in meta_group.items():
                        if len(meta_elems[mg]) != 0:
                            tab_write("blob{threshold %.4g // %s \n" % (mob.data.threshold, mg))
                            for elems in meta_elems[mg]:
                                elem = elems[0]
                                loc = elem.co
                                stiffness = elem.stiffness
                                if elem.use_negative:
                                    stiffness = -stiffness
                                if elem.type == 'BALL':
                                    tab_write(
                                        "sphere { <%.6g, %.6g, %.6g>, %.4g, %.4g "
                                        % (loc.x, loc.y, loc.z, elem.radius, stiffness)
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")
                                elif elem.type == 'ELLIPSOID':
                                    tab_write(
                                        "sphere{ <%.6g, %.6g, %.6g>,%.4g,%.4g "
                                        % (
                                            loc.x / elem.size_x,
                                            loc.y / elem.size_y,
                                            loc.z / elem.size_z,
                                            elem.radius,
                                            stiffness,
                                        )
                                    )
                                    tab_write(
                                        "scale <%.6g, %.6g, %.6g>"
                                        % (elem.size_x, elem.size_y, elem.size_z)
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")
                                elif elem.type == 'CAPSULE':
                                    tab_write(
                                        "cylinder{ <%.6g, %.6g, %.6g>,<%.6g, %.6g, %.6g>,%.4g,%.4g "
                                        % (
                                            (loc.x - elem.size_x),
                                            loc.y,
                                            loc.z,
                                            (loc.x + elem.size_x),
                                            loc.y,
                                            loc.z,
                                            elem.radius,
                                            stiffness,
                                        )
                                    )
                                    # tab_write("scale <%.6g, %.6g, %.6g>" % (elem.size_x, elem.size_y, elem.size_z))
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")

                                elif elem.type == 'CUBE':
                                    tab_write(
                                        "cylinder { -x*8, +x*8,%.4g,%.4g translate<%.6g,%.6g,%.6g> scale  <1/4,1,1> scale <%.6g, %.6g, %.6g>\n"
                                        % (
                                            elem.radius * 2.0,
                                            stiffness / 4.0,
                                            loc.x,
                                            loc.y,
                                            loc.z,
                                            elem.size_x,
                                            elem.size_y,
                                            elem.size_z,
                                        )
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")
                                    tab_write(
                                        "cylinder { -y*8, +y*8,%.4g,%.4g translate<%.6g,%.6g,%.6g> scale <1,1/4,1> scale <%.6g, %.6g, %.6g>\n"
                                        % (
                                            elem.radius * 2.0,
                                            stiffness / 4.0,
                                            loc.x,
                                            loc.y,
                                            loc.z,
                                            elem.size_x,
                                            elem.size_y,
                                            elem.size_z,
                                        )
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")
                                    tab_write(
                                        "cylinder { -z*8, +z*8,%.4g,%.4g translate<%.6g,%.6g,%.6g> scale <1,1,1/4> scale <%.6g, %.6g, %.6g>\n"
                                        % (
                                            elem.radius * 2.0,
                                            stiffness / 4.0,
                                            loc.x,
                                            loc.y,
                                            loc.z,
                                            elem.size_x,
                                            elem.size_y,
                                            elem.size_z,
                                        )
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")

                                elif elem.type == 'PLANE':
                                    tab_write(
                                        "cylinder { -x*8, +x*8,%.4g,%.4g translate<%.6g,%.6g,%.6g> scale  <1/4,1,1> scale <%.6g, %.6g, %.6g>\n"
                                        % (
                                            elem.radius * 2.0,
                                            stiffness / 4.0,
                                            loc.x,
                                            loc.y,
                                            loc.z,
                                            elem.size_x,
                                            elem.size_y,
                                            elem.size_z,
                                        )
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")
                                    tab_write(
                                        "cylinder { -y*8, +y*8,%.4g,%.4g translate<%.6g,%.6g,%.6g> scale <1,1/4,1> scale <%.6g, %.6g, %.6g>\n"
                                        % (
                                            elem.radius * 2.0,
                                            stiffness / 4.0,
                                            loc.x,
                                            loc.y,
                                            loc.z,
                                            elem.size_x,
                                            elem.size_y,
                                            elem.size_z,
                                        )
                                    )
                                    write_matrix(global_matrix @ elems[1].matrix_world)
                                    tab_write("}\n")

                            try:
                                one_material = elems[1].data.materials[
                                    0
                                ]  # lame! - blender cant do enything else.
                            except BaseException as e:
                                print(e.__doc__)
                                print('An exception occurred: {}'.format(e))
                                one_material = None
                            if one_material:
                                diffuse_color = one_material.diffuse_color
                                trans = 1.0 - one_material.pov.alpha
                                if (
                                    one_material.use_transparency
                                    and one_material.transparency_method == 'RAYTRACE'
                                ):
                                    pov_filter = one_material.pov_raytrace_transparency.filter * (
                                        1.0 - one_material.alpha
                                    )
                                    trans = (1.0 - one_material.pov.alpha) - pov_filter
                                else:
                                    pov_filter = 0.0
                                material_finish = material_names_dictionary[one_material.name]
                                tab_write(
                                    "pigment {srgbft<%.3g, %.3g, %.3g, %.3g, %.3g>} \n"
                                    % (
                                        diffuse_color[0],
                                        diffuse_color[1],
                                        diffuse_color[2],
                                        pov_filter,
                                        trans,
                                    )
                                )
                                tab_write("finish{%s} " % safety(material_finish, ref_level_bound=2))
                            else:
                                material_finish = DEF_MAT_NAME
                                trans = 0.0
                                tab_write(
                                    "pigment{srgbt<1,1,1,%.3g>} finish{%s} "
                                    % (trans, safety(material_finish, ref_level_bound=2))
                                )

                                write_object_material_interior(one_material, mob, tab_write)
                                # write_object_material_interior(one_material, elems[1])
                                tab_write("radiosity{importance %3g}\n" % mob.pov.importance_value)
                                tab_write("}\n\n")  # End of Metaball block

        '''
                meta = ob.data

                # important because no elements will break parsing.
                elements = [elem for elem in meta.elements if elem.type in {'BALL', 'ELLIPSOID'}]

                if elements:
                    tab_write("blob {\n")
                    tab_write("threshold %.4g\n" % meta.threshold)
                    importance = ob.pov.importance_value

                    try:
                        material = meta.materials[0]  # lame! - blender cant do enything else.
                    except:
                        material = None

                    for elem in elements:
                        loc = elem.co

                        stiffness = elem.stiffness
                        if elem.use_negative:
                            stiffness = - stiffness

                        if elem.type == 'BALL':

                            tab_write("sphere { <%.6g, %.6g, %.6g>, %.4g, %.4g }\n" %
                                     (loc.x, loc.y, loc.z, elem.radius, stiffness))

                            # After this wecould do something simple like...
                            #     "pigment {Blue} }"
                            # except we'll write the color

                        elif elem.type == 'ELLIPSOID':
                            # location is modified by scale
                            tab_write("sphere { <%.6g, %.6g, %.6g>, %.4g, %.4g }\n" %
                                     (loc.x / elem.size_x,
                                      loc.y / elem.size_y,
                                      loc.z / elem.size_z,
                                      elem.radius, stiffness))
                            tab_write("scale <%.6g, %.6g, %.6g> \n" %
                                     (elem.size_x, elem.size_y, elem.size_z))

                    if material:
                        diffuse_color = material.diffuse_color
                        trans = 1.0 - material.pov.alpha
                        if material.use_transparency and material.transparency_method == 'RAYTRACE':
                            pov_filter = material.pov_raytrace_transparency.filter * (1.0 - material.alpha)
                            trans = (1.0 - material.pov.alpha) - pov_filter
                        else:
                            pov_filter = 0.0

                        material_finish = material_names_dictionary[material.name]

                        tab_write("pigment {srgbft<%.3g, %.3g, %.3g, %.3g, %.3g>} \n" %
                                 (diffuse_color[0], diffuse_color[1], diffuse_color[2],
                                  pov_filter, trans))
                        tab_write("finish {%s}\n" % safety(material_finish, ref_level_bound=2))

                    else:
                        tab_write("pigment {srgb 1} \n")
                        # Write the finish last.
                        tab_write("finish {%s}\n" % (safety(DEF_MAT_NAME, ref_level_bound=2)))

                    write_object_material_interior(material, elems[1])

                    write_matrix(global_matrix @ ob.matrix_world)
                    # Importance for radiosity sampling added here
                    tab_write("radiosity { \n")
                    # importance > ob.pov.importance_value
                    tab_write("importance %3g \n" % importance)
                    tab_write("}\n")

                    tab_write("}\n")  # End of Metaball block

                    if comments and len(metas) >= 1:
                        file.write("\n")
        '''

        def export_global_settings(scene):
            """write all POV global settings to exported file """
            # Imperial units warning
            if scene.unit_settings.system == "IMPERIAL":
                print("Warning: Imperial units not supported")

            tab_write("global_settings {\n")
            tab_write("assumed_gamma 1.0\n")
            tab_write("max_trace_level %d\n" % scene.pov.max_trace_level)

            if scene.pov.global_settings_advanced:
                if not scene.pov.radio_enable:
                    file.write("    adc_bailout %.6f\n" % scene.pov.adc_bailout)
                file.write("    ambient_light <%.6f,%.6f,%.6f>\n" % scene.pov.ambient_light[:])
                file.write("    irid_wavelength <%.6f,%.6f,%.6f>\n" % scene.pov.irid_wavelength[:])
                file.write("    number_of_waves %s\n" % scene.pov.number_of_waves)
                file.write("    noise_generator %s\n" % scene.pov.noise_generator)
            if scene.pov.radio_enable:
                tab_write("radiosity {\n")
                tab_write("adc_bailout %.4g\n" % scene.pov.radio_adc_bailout)
                tab_write("brightness %.4g\n" % scene.pov.radio_brightness)
                tab_write("count %d\n" % scene.pov.radio_count)
                tab_write("error_bound %.4g\n" % scene.pov.radio_error_bound)
                tab_write("gray_threshold %.4g\n" % scene.pov.radio_gray_threshold)
                tab_write("low_error_factor %.4g\n" % scene.pov.radio_low_error_factor)
                tab_write("maximum_reuse %.4g\n" % scene.pov.radio_maximum_reuse)
                tab_write("minimum_reuse %.4g\n" % scene.pov.radio_minimum_reuse)
                tab_write("nearest_count %d\n" % scene.pov.radio_nearest_count)
                tab_write("pretrace_start %.3g\n" % scene.pov.radio_pretrace_start)
                tab_write("pretrace_end %.3g\n" % scene.pov.radio_pretrace_end)
                tab_write("recursion_limit %d\n" % scene.pov.radio_recursion_limit)
                tab_write("always_sample %d\n" % scene.pov.radio_always_sample)
                tab_write("normal %d\n" % scene.pov.radio_normal)
                tab_write("media %d\n" % scene.pov.radio_media)
                tab_write("subsurface %d\n" % scene.pov.radio_subsurface)
                tab_write("}\n")
            once_sss = 1
            once_ambient = 1
            once_photons = 1
            for material in bpy.data.materials:
                if material.pov_subsurface_scattering.use and once_sss:
                    # In pov, the scale has reversed influence compared to blender. these number
                    # should correct that
                    tab_write(
                        "mm_per_unit %.6f\n" % (material.pov_subsurface_scattering.scale * 1000.0)
                    )
                    # 1000 rather than scale * (-100.0) + 15.0))

                    # In POV-Ray, the scale factor for all subsurface shaders needs to be the same

                    # formerly sslt_samples were multiplied by 100 instead of 10
                    sslt_samples = (11 - material.pov_subsurface_scattering.error_threshold) * 10

                    tab_write("subsurface { samples %d, %d }\n" % (sslt_samples, sslt_samples / 10))
                    once_sss = 0

                if world and once_ambient:
                    tab_write("ambient_light rgb<%.3g, %.3g, %.3g>\n" % world.pov.ambient_color[:])
                    once_ambient = 0

                if scene.pov.photon_enable:
                    if once_photons and (
                        material.pov.refraction_type == "2" or material.pov.photons_reflection
                    ):
                        tab_write("photons {\n")
                        tab_write("spacing %.6f\n" % scene.pov.photon_spacing)
                        tab_write("max_trace_level %d\n" % scene.pov.photon_max_trace_level)
                        tab_write("adc_bailout %.3g\n" % scene.pov.photon_adc_bailout)
                        tab_write(
                            "gather %d, %d\n"
                            % (scene.pov.photon_gather_min, scene.pov.photon_gather_max)
                        )
                        if scene.pov.photon_map_file_save_load in {'save'}:
                            ph_file_name = 'Photon_map_file.ph'
                            if scene.pov.photon_map_file != '':
                                ph_file_name = scene.pov.photon_map_file + '.ph'
                            ph_file_dir = tempfile.gettempdir()
                            path = bpy.path.abspath(scene.pov.photon_map_dir)
                            if os.path.exists(path):
                                ph_file_dir = path
                            full_file_name = os.path.join(ph_file_dir, ph_file_name)
                            tab_write('save_file "%s"\n' % full_file_name)
                            scene.pov.photon_map_file = full_file_name
                        if scene.pov.photon_map_file_save_load in {'load'}:
                            full_file_name = bpy.path.abspath(scene.pov.photon_map_file)
                            if os.path.exists(full_file_name):
                                tab_write('load_file "%s"\n' % full_file_name)
                        tab_write("}\n")
                        once_photons = 0

            tab_write("}\n")

        # sel = renderable_objects() #removed for booleans
        if comments:
            file.write(
                "//----------------------------------------------\n"
                "//--Exported with POV-Ray exporter for Blender--\n"
                "//----------------------------------------------\n\n"
            )
        file.write("#version 3.7;\n")  # Switch below as soon as 3.8 beta gets easy linked
        # file.write("#version 3.8;\n")
        file.write(
            "#declare Default_texture = texture{pigment {rgb 0.8} " "finish {brilliance 3.8} }\n\n"
        )
        if comments:
            file.write("\n//--Global settings--\n\n")

        export_global_settings(scene)

        if comments:
            file.write("\n//--Custom Code--\n\n")
        scripting.export_custom_code(file)

        if comments:
            file.write("\n//--Patterns Definitions--\n\n")
        local_pattern_names = []
        for texture in bpy.data.textures:  # ok?
            if texture.users > 0:
                current_pat_name = string_strip_hyphen(bpy.path.clean_name(texture.name))
                # string_strip_hyphen(patternNames[texture.name]) #maybe instead of the above
                local_pattern_names.append(current_pat_name)
                # use above list to prevent writing texture instances several times and assign in mats?
                if (
                    texture.type not in {'NONE', 'IMAGE'} and texture.pov.tex_pattern_type == 'emulator'
                ) or (texture.type in {'NONE', 'IMAGE'} and texture.pov.tex_pattern_type != 'emulator'):
                    file.write("\n#declare PAT_%s = \n" % current_pat_name)
                    file.write(shading.export_pattern(texture))
                file.write("\n")
        if comments:
            file.write("\n//--Background--\n\n")

        scenography.export_world(scene.world, scene, global_matrix, tab_write)

        if comments:
            file.write("\n//--Cameras--\n\n")

        scenography.export_camera(scene, global_matrix, render, tab_write)

        if comments:
            file.write("\n//--Lamps--\n\n")

        for ob in bpy.data.objects:
            if ob.type == 'MESH':
                for mod in ob.modifiers:
                    if mod.type == 'BOOLEAN' and mod.object not in csg_list:
                        csg_list.append(mod.object)
        if csg_list:
            csg = False
            sel = no_renderable_objects()
            # export non rendered boolean objects operands
            object_mesh_topology.export_meshes(
                preview_dir,
                file,
                scene,
                sel,
                csg,
                string_strip_hyphen,
                safety,
                write_object_modifiers,
                material_names_dictionary,
                write_object_material_interior,
                scenography.exported_lights_count,
                unpacked_images,
                image_format,
                img_map,
                img_map_transforms,
                path_image,
                smoke_path,
                global_matrix,
                write_matrix,
                using_uberpov,
                comments,
                linebreaksinlists,
                tab,
                tab_level,
                tab_write,
                info_callback,
            )

        csg = True
        sel = renderable_objects()

        scenography.export_lights(
            [L for L in sel if (L.type == 'LIGHT' and L.pov.object_as != 'RAINBOW')],
            file,
            scene,
            global_matrix,
            write_matrix,
            tab_write,
        )

        if comments:
            file.write("\n//--Rainbows--\n\n")
        scenography.export_rainbows(
            [L for L in sel if (L.type == 'LIGHT' and L.pov.object_as == 'RAINBOW')],
            file,
            scene,
            global_matrix,
            write_matrix,
            tab_write,
        )

        if comments:
            file.write("\n//--Special Curves--\n\n")
        for c in sel:
            if c.is_modified(scene, 'RENDER'):
                continue  # don't export as pov curves objects with modifiers, but as mesh
            # Implicit else-if (as not skipped by previous "continue")
            if c.type == 'CURVE' and (c.pov.curveshape in {'lathe', 'sphere_sweep', 'loft', 'birail'}):
                object_curve_topology.export_curves(file, c, string_strip_hyphen, tab_write)

        if comments:
            file.write("\n//--Material Definitions--\n\n")
        # write a default pigment for objects with no material (comment out to show black)
        file.write("#default{ pigment{ color srgb 0.8 }}\n")
        # Convert all materials to strings we can access directly per vertex.
        # exportMaterials()
        shading.write_material(
            using_uberpov,
            DEF_MAT_NAME,
            tab_write,
            safety,
            comments,
            unique_name,
            material_names_dictionary,
            None,
        )  # default material
        for material in bpy.data.materials:
            if material.users > 0:
                r, g, b, a = material.diffuse_color[:]
                pigment_color = "pigment {rgbt <%.4g,%.4g,%.4g,%.4g>}" % (r, g, b, 1 - a)
                if material.pov.material_use_nodes:
                    # Also make here other pigment_color fallback using BSDF node main color ?
                    ntree = material.node_tree
                    pov_mat_name = string_strip_hyphen(bpy.path.clean_name(material.name))
                    if len(ntree.nodes) == 0:
                        file.write('#declare %s = texture {%s}\n' % (pov_mat_name, pigment_color))
                    else:
                        shading.write_nodes(pov_mat_name, ntree, file)

                    for node in ntree.nodes:
                        if node:
                            if node.bl_idname == "PovrayOutputNode":
                                if node.inputs["Texture"].is_linked:
                                    for link in ntree.links:
                                        if link.to_node.bl_idname == "PovrayOutputNode":
                                            pov_mat_name = (
                                                string_strip_hyphen(
                                                    bpy.path.clean_name(link.from_node.name)
                                                )
                                                + "_%s" % pov_mat_name
                                            )
                                else:
                                    file.write(
                                        '#declare %s = texture {%s}\n' % (pov_mat_name, pigment_color)
                                    )
                else:
                    shading.write_material(
                        using_uberpov,
                        DEF_MAT_NAME,
                        tab_write,
                        safety,
                        comments,
                        unique_name,
                        material_names_dictionary,
                        material,
                    )
                # attributes are all the variables needed by the other python file...
        if comments:
            file.write("\n")

        export_meta([m for m in sel if m.type == 'META'])

        if comments:
            file.write("//--Mesh objects--\n")

        # tbefore = time.time()
        object_mesh_topology.export_meshes(
            preview_dir,
            file,
            scene,
            sel,
            csg,
            string_strip_hyphen,
            safety,
            write_object_modifiers,
            material_names_dictionary,
            write_object_material_interior,
            scenography.exported_lights_count,
            unpacked_images,
            image_format,
            img_map,
            img_map_transforms,
            path_image,
            smoke_path,
            global_matrix,
            write_matrix,
            using_uberpov,
            comments,
            linebreaksinlists,
            tab,
            tab_level,
            tab_write,
            info_callback,
        )
        # totime = time.time() - tbefore
        # print("export_meshes took" + str(totime))

        # What follow used to happen here:
        # export_camera()
        # scenography.export_world(scene.world, scene, global_matrix, tab_write)
        # export_global_settings(scene)
        # MR:..and the order was important for implementing pov 3.7 baking
        #      (mesh camera) comment for the record
        # CR: Baking should be a special case than. If "baking", than we could change the order.

    if not file.closed:
        file.close()

def write_pov_ini(filename_ini, filename_log, filename_pov, filename_image):
    """Write ini file."""
    feature_set = bpy.context.preferences.addons[__package__].preferences.branch_feature_set_povray
    using_uberpov = feature_set == 'uberpov'
    # scene = bpy.data.scenes[0]
    scene = bpy.context.scene
    render = scene.render

    x = int(render.resolution_x * render.resolution_percentage * 0.01)
    y = int(render.resolution_y * render.resolution_percentage * 0.01)

    with open(filename_ini, "w") as file:
        file.write("Version=3.7\n")
        # write povray text stream to temporary file of same name with _log suffix
        # file.write("All_File='%s'\n" % filename_log)
        # DEBUG.OUT log if none specified:
        file.write("All_File=1\n")

        file.write("Input_File_Name='%s'\n" % filename_pov)
        file.write("Output_File_Name='%s'\n" % filename_image)

        file.write("Width=%d\n" % x)
        file.write("Height=%d\n" % y)

        # Border render.
        if render.use_border:
            file.write("Start_Column=%4g\n" % render.border_min_x)
            file.write("End_Column=%4g\n" % render.border_max_x)

            file.write("Start_Row=%4g\n" % (1.0 - render.border_max_y))
            file.write("End_Row=%4g\n" % (1.0 - render.border_min_y))

        file.write("Bounding_Method=2\n")  # The new automatic BSP is faster in most scenes

        # Activated (turn this back off when better live exchange is done between the two programs
        # (see next comment)
        file.write("Display=1\n")
        file.write("Pause_When_Done=0\n")
        # PNG, with POV-Ray 3.7, can show background color with alpha. In the long run using the
        # POV-Ray interactive preview like bishop 3D could solve the preview for all formats.
        file.write("Output_File_Type=N\n")
        # file.write("Output_File_Type=T\n") # TGA, best progressive loading
        file.write("Output_Alpha=1\n")

        if scene.pov.antialias_enable:
            # method 2 (recursive) with higher max subdiv forced because no mipmapping in POV-Ray
            # needs higher sampling.
            # aa_mapping = {"5": 2, "8": 3, "11": 4, "16": 5}
            if using_uberpov:
                method = {"0": 1, "1": 2, "2": 3}
            else:
                method = {"0": 1, "1": 2, "2": 2}
            file.write("Antialias=on\n")
            file.write("Antialias_Depth=%d\n" % scene.pov.antialias_depth)
            file.write("Antialias_Threshold=%.3g\n" % scene.pov.antialias_threshold)
            if using_uberpov and scene.pov.antialias_method == '2':
                file.write("Sampling_Method=%s\n" % method[scene.pov.antialias_method])
                file.write("Antialias_Confidence=%.3g\n" % scene.pov.antialias_confidence)
            else:
                file.write("Sampling_Method=%s\n" % method[scene.pov.antialias_method])
            file.write("Antialias_Gamma=%.3g\n" % scene.pov.antialias_gamma)
            if scene.pov.jitter_enable:
                file.write("Jitter=on\n")
                file.write("Jitter_Amount=%3g\n" % scene.pov.jitter_amount)
            else:
                file.write("Jitter=off\n")  # prevent animation flicker

        else:
            file.write("Antialias=off\n")
    if not file.closed:
        file.close()


class PovrayRender(bpy.types.RenderEngine):
    """Define the external renderer"""

    bl_idname = 'POVRAY_RENDER'
    bl_label = "Persitence Of Vision"
    bl_use_shading_nodes_custom = False
    DELAY = 0.5

    @staticmethod
    def _locate_binary():
        """Identify POV engine"""
        addon_prefs = bpy.context.preferences.addons[__package__].preferences

        # Use the system preference if its set.
        pov_binary = addon_prefs.filepath_povray
        if pov_binary:
            if os.path.exists(pov_binary):
                return pov_binary
            # Implicit else, as here return was still not triggered:
            print("User Preferences path to povray %r NOT FOUND, checking $PATH" % pov_binary)

        # Windows Only
        # assume if there is a 64bit binary that the user has a 64bit capable OS
        if platform.startswith('win'):
            import winreg

            win_reg_key = winreg.OpenKey(
                winreg.HKEY_CURRENT_USER, "Software\\POV-Ray\\v3.7\\Windows"
            )
            win_home = winreg.QueryValueEx(win_reg_key, "Home")[0]

            # First try 64bits UberPOV
            pov_binary = os.path.join(win_home, "bin", "uberpov64.exe")
            if os.path.exists(pov_binary):
                return pov_binary