Where can I find a specification document of displacement file "baked_mesh_disp0.exr" obtained from Full Quality result run by Reality Composer Pro?
I ran Reality Composer Pro, selected Full Quality and ran Create Model, and obtained *.usdz, which I renamed to *.zip and unzipped. Then I found 5 maps including "baked_mesh_disp0.exr" and I want to know its data specification.
I am curious why Reality Composer Pro is exporting a displacement map, as my understand was that RealityKit doesn't support Displacement maps for PBR textures. Was this for a surface shader?
If you're asking about EXR, this is the OpenEXR file format: https://openexr.com. It is essentially a high-dynamic range image format stored in a linear format. For example, it can store values greater than 0.0...1.0, which are not usually possible with low-dynamic range formats such as JPEG. Additionally, unlike image formats that store in a non-linear colorspace such as Adobe RGB, linear colorspace means that the numerical intensity of a pixel correspond proportionally to their perceived intensity, in other words a value of 0.5 is half as intense/bright as a value of 1.0, and a quarter as intense/bright as a value of 2.0...etc. This is not the case with non-linear colorspaces that are often found in formats such as JPEG.
EXR is often used as the image format for USD because they are both open source formats that originated in the visual effects community.
You should be able to open EXR files with either Xcode, or the Preview app on macOS.
Thank you very much [@Matt Cox](https://developer.apple.com/forums/profile/Matt Cox)
I thought the fact that a displacement map is generated in Reality Composer Pro means there should be some way to used it in rendering (I hope...) if not in RealityKit.
The obtained displacement map looks something meaningful (it is not all-zero, for example; in fact, the numerical values range from 0.497 to 0.502, in my experiment. It looks like something meaningful, does it not?)
Therefore I thought this is something somebody desinged with intention. Does anybody know its specificaiton?