[Bf-extensions-cvs] [9d903a93] master: glTF importer/exporter: Export lights using correcct units
Julien Duroure
noreply at git.blender.org
Fri Oct 21 18:50:28 CEST 2022
Commit: 9d903a93f03b11ede3abaef14052869f50d650d3
Author: Julien Duroure
Date: Fri Oct 21 18:47:53 2022 +0200
Branches: master
https://developer.blender.org/rBA9d903a93f03b11ede3abaef14052869f50d650d3
glTF importer/exporter: Export lights using correcct units
===================================================================
M io_scene_gltf2/__init__.py
M io_scene_gltf2/blender/com/gltf2_blender_conversion.py
M io_scene_gltf2/blender/exp/gltf2_blender_gather_lights.py
M io_scene_gltf2/blender/imp/gltf2_blender_light.py
===================================================================
diff --git a/io_scene_gltf2/__init__.py b/io_scene_gltf2/__init__.py
index 2c61a9ed..08260263 100755
--- a/io_scene_gltf2/__init__.py
+++ b/io_scene_gltf2/__init__.py
@@ -4,7 +4,7 @@
bl_info = {
'name': 'glTF 2.0 format',
'author': 'Julien Duroure, Scurest, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
- "version": (3, 4, 39),
+ "version": (3, 4, 40),
'blender': (3, 3, 0),
'location': 'File > Import-Export',
'description': 'Import-Export as glTF 2.0',
@@ -98,7 +98,21 @@ def on_export_format_changed(self, context):
)
-class ExportGLTF2_Base:
+class ConvertGLTF2_Base:
+ """Base class containing options that should be exposed during both import and export."""
+
+ convert_lighting_mode: EnumProperty(
+ name='Lighting Mode',
+ items=(
+ ('SPEC', 'Standard', 'Physically-based glTF lighting units (cd, lx, nt)'),
+ ('COMPAT', 'Unitless', 'Non-physical, unitless lighting. Useful when exposure controls are not available'),
+ ('RAW', 'Raw (Deprecated)', 'Blender lighting strengths with no conversion'),
+ ),
+ description='Optional backwards compatibility for non-standard render engines. Applies to lights',# TODO: and emissive materials',
+ default='SPEC'
+ )
+
+class ExportGLTF2_Base(ConvertGLTF2_Base):
# TODO: refactor to avoid boilerplate
def __init__(self):
@@ -643,6 +657,7 @@ class ExportGLTF2_Base:
export_settings['gltf_morph_tangent'] = False
export_settings['gltf_lights'] = self.export_lights
+ export_settings['gltf_lighting_mode'] = self.convert_lighting_mode
export_settings['gltf_binary'] = bytearray()
export_settings['gltf_binaryfilename'] = (
@@ -778,7 +793,7 @@ class GLTF_PT_export_transform(bpy.types.Panel):
class GLTF_PT_export_geometry(bpy.types.Panel):
bl_space_type = 'FILE_BROWSER'
bl_region_type = 'TOOL_PROPS'
- bl_label = "Geometry"
+ bl_label = "Data"
bl_parent_id = "FILE_PT_operator"
bl_options = {'DEFAULT_CLOSED'}
@@ -876,6 +891,28 @@ class GLTF_PT_export_geometry_original_pbr(bpy.types.Panel):
layout.prop(operator, 'export_original_specular')
+class GLTF_PT_export_geometry_lighting(bpy.types.Panel):
+ bl_space_type = 'FILE_BROWSER'
+ bl_region_type = 'TOOL_PROPS'
+ bl_label = "Lighting"
+ bl_parent_id = "GLTF_PT_export_geometry"
+ bl_options = {'DEFAULT_CLOSED'}
+
+ @classmethod
+ def poll(cls, context):
+ sfile = context.space_data
+ operator = sfile.active_operator
+ return operator.bl_idname == "EXPORT_SCENE_OT_gltf"
+
+ def draw(self, context):
+ layout = self.layout
+ layout.use_property_split = True
+ layout.use_property_decorate = False # No animation.
+
+ sfile = context.space_data
+ operator = sfile.active_operator
+
+ layout.prop(operator, 'convert_lighting_mode')
class GLTF_PT_export_geometry_compression(bpy.types.Panel):
bl_space_type = 'FILE_BROWSER'
@@ -1106,7 +1143,7 @@ def menu_func_export(self, context):
self.layout.operator(ExportGLTF2.bl_idname, text='glTF 2.0 (.glb/.gltf)')
-class ImportGLTF2(Operator, ImportHelper):
+class ImportGLTF2(Operator, ConvertGLTF2_Base, ImportHelper):
"""Load a glTF 2.0 file"""
bl_idname = 'import_scene.gltf'
bl_label = 'Import glTF 2.0'
@@ -1189,6 +1226,7 @@ class ImportGLTF2(Operator, ImportHelper):
layout.prop(self, 'import_shading')
layout.prop(self, 'guess_original_bind_pose')
layout.prop(self, 'bone_heuristic')
+ layout.prop(self, 'convert_lighting_mode')
def invoke(self, context, event):
import sys
@@ -1320,6 +1358,7 @@ classes = (
GLTF_PT_export_geometry_mesh,
GLTF_PT_export_geometry_material,
GLTF_PT_export_geometry_original_pbr,
+ GLTF_PT_export_geometry_lighting,
GLTF_PT_export_geometry_compression,
GLTF_PT_export_animation,
GLTF_PT_export_animation_export,
diff --git a/io_scene_gltf2/blender/com/gltf2_blender_conversion.py b/io_scene_gltf2/blender/com/gltf2_blender_conversion.py
index 85ab654a..8b1e5452 100755
--- a/io_scene_gltf2/blender/com/gltf2_blender_conversion.py
+++ b/io_scene_gltf2/blender/com/gltf2_blender_conversion.py
@@ -5,6 +5,9 @@ from math import sin, cos
import numpy as np
from io_scene_gltf2.io.com import gltf2_io_constants
+PBR_WATTS_TO_LUMENS = 683
+# Industry convention, biological peak at 555nm, scientific standard as part of SI candela definition.
+
def texture_transform_blender_to_gltf(mapping_transform):
"""
Converts the offset/rotation/scale from a Mapping node applied in Blender's
diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_lights.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_lights.py
index 615bd01b..587535df 100644
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gather_lights.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_lights.py
@@ -7,6 +7,7 @@ from typing import Optional, List, Dict, Any
from io_scene_gltf2.blender.exp.gltf2_blender_gather_cache import cached
from ..com.gltf2_blender_extras import generate_extras
+from ..com.gltf2_blender_conversion import PBR_WATTS_TO_LUMENS
from io_scene_gltf2.io.com import gltf2_io_lights_punctual
from io_scene_gltf2.io.com import gltf2_io_debug
@@ -50,7 +51,7 @@ def __gather_color(blender_lamp, export_settings) -> Optional[List[float]]:
return list(blender_lamp.color)
-def __gather_intensity(blender_lamp, _) -> Optional[float]:
+def __gather_intensity(blender_lamp, export_settings) -> Optional[float]:
emission_node = __get_cycles_emission_node(blender_lamp)
if emission_node is not None:
if blender_lamp.type != 'SUN':
@@ -68,9 +69,26 @@ def __gather_intensity(blender_lamp, _) -> Optional[float]:
emission_strength = blender_lamp.energy
else:
emission_strength = emission_node.inputs["Strength"].default_value
+ else:
+ emission_strength = blender_lamp.energy
+ if export_settings['gltf_lighting_mode'] == 'RAW':
return emission_strength
-
- return blender_lamp.energy
+ else:
+ # Assume at this point the computed strength is still in the appropriate watt-related SI unit, which if everything up to here was done with physical basis it hopefully should be.
+ if blender_lamp.type == 'SUN': # W/m^2 in Blender to lm/m^2 for GLTF/KHR_lights_punctual.
+ emission_luminous = emission_strength
+ else:
+ # Other than directional, only point and spot lamps are supported by GLTF.
+ # In Blender, points are omnidirectional W, and spots are specified as if they're points.
+ # Point and spot should both be lm/r^2 in GLTF.
+ emission_luminous = emission_strength / (4*math.pi)
+ if export_settings['gltf_lighting_mode'] == 'SPEC':
+ emission_luminous *= PBR_WATTS_TO_LUMENS
+ elif export_settings['gltf_lighting_mode'] == 'COMPAT':
+ pass # Just so we have an exhaustive tree to catch bugged values.
+ else:
+ raise ValueError(export_settings['gltf_lighting_mode'])
+ return emission_luminous
def __gather_spot(blender_lamp, export_settings) -> Optional[gltf2_io_lights_punctual.LightSpot]:
diff --git a/io_scene_gltf2/blender/imp/gltf2_blender_light.py b/io_scene_gltf2/blender/imp/gltf2_blender_light.py
index fb060598..034d41ab 100644
--- a/io_scene_gltf2/blender/imp/gltf2_blender_light.py
+++ b/io_scene_gltf2/blender/imp/gltf2_blender_light.py
@@ -6,6 +6,7 @@ from math import pi
from ..com.gltf2_blender_extras import set_extras
from io_scene_gltf2.io.imp.gltf2_io_user_extensions import import_user_extensions
+from ..com.gltf2_blender_conversion import PBR_WATTS_TO_LUMENS
class BlenderLight():
@@ -21,7 +22,7 @@ class BlenderLight():
import_user_extensions('gather_import_light_before_hook', gltf, vnode, pylight)
if pylight['type'] == "directional":
- light = BlenderLight.create_directional(gltf, light_id)
+ light = BlenderLight.create_directional(gltf, light_id) # ...Why not pass the pylight?
elif pylight['type'] == "point":
light = BlenderLight.create_point(gltf, light_id)
elif pylight['type'] == "spot":
@@ -30,9 +31,6 @@ class BlenderLight():
if 'color' in pylight.keys():
light.color = pylight['color']
- if 'intensity' in pylight.keys():
- light.energy = pylight['intensity']
-
# TODO range
set_extras(light, pylight.get('extras'))
@@ -44,11 +42,33 @@ class BlenderLight():
pylight = gltf.data.extensions['KHR_lights_punctual']['lights'][light_id]
if 'name' not in pylight.keys():
- pylight['name'] = "Sun"
+ pylight['name'] = "Sun" # Uh... Is it okay to mutate the import data?
sun = bpy.data.lights.new(name=pylight['name'], type="SUN")
+
+ if 'intensity' in pylight.keys():
+ if gltf.import_settings['convert_lighting_mode'] == 'SPEC':
+ sun.energy = pylight['intensity'] / PBR_WATTS_TO_LUMENS
+ elif gltf.import_settings['convert_lighting_mode'] == 'COMPAT':
+ sun.energy = pylight['intensity']
+ elif gltf.import_settings['convert_lighting_mode'] == 'RAW':
+ sun.energy = pylight['intensity']
+ else:
+ raise ValueError(gltf.import_settings['convert_lighting_mode'])
+
return sun
+ @staticmethod
+ def _calc_energy_pointlike(gltf, pylight):
+ if gltf.import_settings['convert_lighting_mode'] == 'SPEC':
+ return pylight['intensity'] / PBR_WATTS_TO_LUMENS * 4 * pi
+ elif gltf.import_settings['convert_lighting_mode'] == 'COMPAT':
+ return pylight['intensity'] * 4 * pi
+ elif gltf.import_settings['convert_lighting_mode'] == 'RAW':
+ return pylight['intensity']
+ else:
+ raise ValueError(gltf.import_settings['convert_lighting_mode'])
+
@staticmethod
def create_point(gltf, light_id
@@ Diff output truncated at 10240 characters. @@
More information about the Bf-extensions-cvs
mailing list