OSL Support Status

Supported

• Standard diffuse, translucent, reflection, refraction and microfacet closures
• appleseed-specific Oren Nayar, Ashikhmin-Shirley and Disney's principled BRDF closures
• Emission
• Texture lookups
• Transparency
• Object coordinate systems
• get_attribute and trace calls
• dtime and dPdtime globals

Missing

• Camera, NDC and screen coordinate transforms
• Bump mapping (requires ray differentials)
• The background closure is ignored right now
• Holdout and debug closures are ignored (we need to do some refactorings to support them)
• Add OSL scenes to unit tests

Not yet supported by appleseed

• ShaderGlobal members that depend on ray differentials are set to 0 (we don't have ray differentials in appleseed yet)
• Geometry user data
• Displacement
• Subsurface scattering
• Arbitrary AOVs from shadergroups

Would be nice to have

• Light attenuation shaders
• Named coordinate systems
• More closures

Should work but untested

• Point clouds (using partio)
• Texture3d (using Field3D)