Shader selector for KHR_material_unlit

baseColorFactor	baseColorTexture	alpha mode	Unity shader
o		OPAQUE	Unlit/Color
	o	OPAQUE	Unlit/Texture
o	o	OPAQUE	require custom shader
o		BLEND	require custom shader
	o	BLEND	Unlit/Transparent
o	o	BLEND	require custom shader
o		CUTOUT	----
	o	CUTOUT	Unlit/Transparent Cutout
o	o	CUTOUT	require custom shader

[ ] Import

✅ Export

✅ Default params of KHR_material_unlit

• https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Khronos/KHR_materials_unlit/README.md#extension-compatibility-and-fallback-materials

• https://github.com/ousttrue/UniGLTF/blob/8516dab5532d72d43a2d61995363814c63a83c17/Core/Scripts/Format/ExtensionsAndExtras/KHR_materials_unlit.cs#L14

Custom Shader for KHR_material_unlit full support

MainColor

ColorTexture

AlphaMode

• Opaque
• Blend
• Cutout

CullMode

• Cullback
• Node(doubleSided)

VertexColor

• VertexColor

BlendOp

• Alpha max