Design Nomenclature / Surface & Material

ORM packing

Also called orm, arm packing, rma, channel packing

This entry has not been translated yet and is shown in English.

Storing occlusion, roughness, and metalness in the R, G, and B channels of one texture, since each is a single-channel grayscale quantity and would otherwise waste two thirds of a map. Cuts samplers and memory by three. The channel order is a house convention — ORM, ARM, and RMA are all just labels.

The packed texture at the top, a row of texels in muddy reds and blues captioned as an image of nothing — do not colour-manage it. Below, the same texture exploded into three grayscale strips, arrowed out to the property each one carries: R occlusion dipping through a groove, G roughness wandering, B metalness flipping once from black to white because it is a flag. A boxed warning to the side reads store linear, no sRGB transform.

In practice

Say which order you mean and store it linear, not sRGB. Half the time a material looks wrong the packed map went through a color transform.

Not to be confused with

How this term connects

Ambient occlusionCavity mapCurvature mapDiffuse mapMetalnessRoughnessORM packing
Related Confused with