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vsg-dev / VulkanSceneGraph

Vulkan & C++17 based Scene Graph Project
http://www.vulkanscenegraph.org
MIT License
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PBR Specular missing #609

Closed robertosfield closed 1 year ago

robertosfield commented 1 year ago 
  Hi Robert,

I think the specular code path, as defined by VSG_WORKFLOW_SPECGLOSS, might be missing from the PBR fragment shaders.

Try vsgviewer glTF-Sample-Models/2.0/SpecularTest/glTF-Binary/SpecularTest.glb

Here the spheres render as flat black circles rather than the spherical objects in the screen shots supplied in the glTF directories.

I find the same in my own code where I can modify the diffuseFactor and emissiveFactor of the PbrMaterialValue of a loaded model and see the changes reflected on screen. Modifying specularFactor, metalFactor and roughnessFactor appear to do nothing.

I've traced through vsgXchange while loading the models and can see that hasPbrSpecularGlossiness is true and that VSG_WORKFLOW_SPECGLOSS gets defined. It just doesn't appear to be reflected in the final frag shader.

I've read the discussion that you pointed me to, but I'm not feeling overly confident in my understanding yet, so see what you think from the example above.

Regards, Roland image

Originally posted by @rolandhill in https://github.com/vsg-dev/VulkanSceneGraph/discussions/608

robertosfield commented 1 year ago

Looks to be an issue with lack of support for environment textures in the present vsgXchange::Assimp loader/VSG rather than a bug in existing feature so I'll close this Issue and add it as a feature item for 1.2.