In general, we only allow textures to be made from photo-based sources, using either photogrammetry or photometric stereo workflows.
While we refer to our content as "textures" what we're actually talking about is complete PBR materials made up from several maps.
- The textures should be clear, detailed and accurate to their real-world source, lacking any blur, quality inconsistencies, seams, clone stamping artifacts or tiling artifacts.
- The minimum resolution of the texture maps is 8192x8192, achieved without the use of upscaling.
- The material should be seamless on all axes without any noticeable tiling or cloning artifacts. Occasionally we do accept surfaces that tile on only one axis if it suits the intended application.
- The real-world dimensions of the final material should be recorded, calibrated from real measurements and accurate to ±5%.
- For photogrammetry-based textures, these dimensions should generally be more than 1.8 meters on each axis. Surfaces smaller than this may occasionally be acceptable but only when the surface is highly useful.
- Texture maps required: Diffuse/albedo, roughness, normal (OpenGL standard), displacement, AO, metalness (if applicable).
- All maps should be 16-bit sRGB PNGs, achieved without simply converting lower quality/bit-depth data to a higher quality/bit-depth.
- The diffuse map must be calibrated to a macbeth color chart or some other known white/gray surface to ensure correct exposure and whitebalance.
- The diffuse map should also have little to no lighting, shadows, shading, or specular reflections present. We recommend using a cross-polarized ring flash setup, and when necessary (on surfaces with large features), performing additional delighting utilizing the AO map and blue channel of the normal map to brighten shaded areas. Very diffuse surfaces can however simply be scanned on an overcast day.
- The displacement map must be normalized (in the 0-1 range), but some record of the correct depth must be kept. This can either be a blend file with the material set up, or a low-poly version of the original scan.
- Avoid sharpening any texture maps beyond any subtle lens softness correction.