diff options
Diffstat (limited to 'io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_volume.py')
| -rw-r--r-- | io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_volume.py | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_volume.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_volume.py new file mode 100644 index 00000000..8a69e3f6 --- /dev/null +++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_volume.py @@ -0,0 +1,75 @@ +# SPDX-License-Identifier: Apache-2.0 +# Copyright 2018-2022 The glTF-Blender-IO authors. + +import bpy +from io_scene_gltf2.io.com.gltf2_io_extensions import Extension +from io_scene_gltf2.blender.exp import gltf2_blender_get +from io_scene_gltf2.blender.exp import gltf2_blender_gather_texture_info + + +def export_volume(blender_material, export_settings): + # Implementation based on https://github.com/KhronosGroup/glTF-Blender-IO/issues/1454#issuecomment-928319444 + + # If no transmission --> No volume + transmission_enabled = False + transmission_socket = gltf2_blender_get.get_socket(blender_material, 'Transmission') + if isinstance(transmission_socket, bpy.types.NodeSocket) and not transmission_socket.is_linked: + transmission_enabled = transmission_socket.default_value > 0 + elif gltf2_blender_get.has_image_node_from_socket(transmission_socket): + transmission_enabled = True + + if transmission_enabled is False: + return None, None + + volume_extension = {} + has_thickness_texture = False + thickness_slots = () + + thicknesss_socket = gltf2_blender_get.get_socket_old(blender_material, 'Thickness') + if thicknesss_socket is None: + # If no thickness (here because there is no glTF Material Output node), no volume extension export + return None, None + + density_socket = gltf2_blender_get.get_socket(blender_material, 'Density', volume=True) + attenuation_color_socket = gltf2_blender_get.get_socket(blender_material, 'Color', volume=True) + # Even if density or attenuation are not set, we export volume extension + + if isinstance(attenuation_color_socket, bpy.types.NodeSocket): + rgb = gltf2_blender_get.get_const_from_default_value_socket(attenuation_color_socket, kind='RGB') + volume_extension['attenuationColor'] = rgb + + if isinstance(density_socket, bpy.types.NodeSocket): + density = gltf2_blender_get.get_const_from_default_value_socket(density_socket, kind='VALUE') + volume_extension['attenuationDistance'] = 1.0 / density if density != 0 else None # infinity (Using None as glTF default) + + + if isinstance(thicknesss_socket, bpy.types.NodeSocket) and not thicknesss_socket.is_linked: + val = thicknesss_socket.default_value + if val == 0.0: + # If no thickness, no volume extension export + return None, None + volume_extension['thicknessFactor'] = val + elif gltf2_blender_get.has_image_node_from_socket(thicknesss_socket): + fac = gltf2_blender_get.get_factor_from_socket(thicknesss_socket, kind='VALUE') + # default value in glTF is 0.0, but if there is a texture without factor, use 1 + volume_extension['thicknessFactor'] = fac if fac != None else 1.0 + has_thickness_texture = True + + # Pack thickness channel (R). + if has_thickness_texture: + thickness_slots = (thicknesss_socket,) + + use_actives_uvmaps = [] + + if len(thickness_slots) > 0: + combined_texture, use_active_uvmap, _ = gltf2_blender_gather_texture_info.gather_texture_info( + thicknesss_socket, + thickness_slots, + export_settings, + ) + if has_thickness_texture: + volume_extension['thicknessTexture'] = combined_texture + if use_active_uvmap: + use_actives_uvmaps.append("thicknessTexture") + + return Extension('KHR_materials_volume', volume_extension, False), use_actives_uvmaps
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