Blender Export issues

[ThibaultGuillaumont]

Some export from blender have corrupted texture on import. This is compared to import to https://threejs.org/editor/

• Specular Only value of 0.5 is tolerated. Spec map as input is not tolerated. (No issue on the ThreeJS viewer) spec_bug.zip

• Specular Tint Specular Tint map is not supported (No issue on the ThreeJS viewer) SpecTint.zip

• Vertex Paint Some models exported by scanners have their texture twice : as a material and as a vertex paint (This issue also exist on the ThreeJS viewer) VertexPaint.zip

• Value on metalness Export from Blender. Issue when PBR shader only have a value for metalness instead of a map (No issue on the ThreeJS viewer) metal.zip

[ThibaultGuillaumont]

Hotfix : Python script to set all material with supported default values.

import bpy
mats = bpy.data.materials

for mat in mats:
     if hasattr(mat.node_tree, "nodes"):
        for node in mat.node_tree.nodes:
            if node.type == 'BSDF_PRINCIPLED':
                for input in node.inputs:
                    if input.name == 'Metallic':
                        input.default_value = 0
                    if input.name == 'Specular':
                        input.default_value = 0.5
                    if input.name == 'Specular Tint':
                        input.default_value = 0

[sdumetz]

Test again once https://github.com/Smithsonian/dpo-voyager/commit/44820eebc8d6ecc1956e198138127b2a5e63baf7 gets merged.