Disclaimer: I am new to all things 3D. There could be a variety of things wrong with what I'm doing that are not unique to RealityKit. Any domain info would be appreciated.
So, I'm following, what I think are, the recommended steps to import a shader-node material from reality composer pro and apply it to another modelEntity.
I do the following:
guard let entity = try? Entity.load(named: "Materials", in: RealityKitContent.realityKitContentBundle) else { return model }
let materialEntity = entity.findEntity(named: "materialModel") as? ModelEntity
guard let materialEntity else { return model }
I then configure a property on it like so:
guard var material = materialEntity.model?.materials[0] as? ShaderGraphMaterial else { return model }
try coreMaterial.setParameter(name: "BaseColor", value: .color(matModel.matCoreUIColor))
I then apply it.
This is what my texture looks like in RealityComposer:
I notice that my rendered object has distortions in the actual RealityView. Note the diagonal lines that appear "Stretched".
What could be doing this? I thought Node Shaders were supposed to be more resilient to distortions like this? I'm not sure if I've got a bug or if I'm using it wrong.
FWIW, this is a shader based on apple's felt material shader. My graph looks like this:
Thanks
So, it turns out that models have internal properties that dictate how image based materials apply to them. You set these properties by "UV-unwrapping" the model, and what surface area of the texture maps to what surface areas on the model.
For one reason or another I thought these UV properties were part of the material itself, but that would mean you couldn't use a material on multiple models, and that would be silly.
I fixed up the UV Mapping of my model with Blender's "Project from View (bounds)" tool, and it now looks the way I expect.