ORM vs RMA vs RMO: Which Packed Texture Layout Should You Use?
Compare ORM, RMA, and RMO packed texture layouts and understand how to choose the right channel order for your engine or shader pipeline.
What the abbreviations mean
ORM usually means occlusion in R, roughness in G, metallic in B. RMA usually means roughness in R, metallic in G, ambient occlusion in B. RMO swaps that order again.
All three layouts solve the same problem, but the channel order changes how the material reads the texture. That is why layout naming should always match the shader contract.
How to choose the right layout
Use the layout your engine template or studio material library already expects. If a material function is built around ORM, exporting RMA only creates avoidable remapping work and debugging noise.
If you are building a new pipeline, choose one layout and enforce it in naming, docs, import presets, and validation tools.
Where mistakes happen
Teams often mix authoring names and runtime names. A texture labeled roughness-metallic-AO may still have been exported in a different order than its filename suggests.
The fastest fix is to inspect channels directly, then repack them into the target layout before the asset reaches production.