KTX2 texture compression
Choose ETC1S or UASTC, adjust KTX2 quality and override or exclude individual textures in SceneOpt Studio.
What KTX2 changes
KTX2 is a texture container. SceneOpt Studio offers ETC1S and UASTC encoding for GPU-compressed textures. This is different from resizing: resizing reduces image dimensions, while encoding changes how pixels are stored. A smaller download and lower GPU memory use are separate goals; compare the result instead of assuming every texture will become smaller.
Automatic, Override and Exclude
Enable KTX2 in optimization settings first. Automatic uses UASTC for any texture referenced by a Normal slot and ETC1S for other slots, including Base color, Metallic roughness, Occlusion and Emissive. Normal maps store directions rather than visible surface colors; preserving their detail helps avoid lighting artifacts. A texture shared across slots is converted once, so inspect every material that uses it.
Select a texture and choose Override to set ETC1S or UASTC and its parameters independently. Choose Exclude to skip KTX2 for that texture. Exclusion does not cancel a separate resize or image replacement. These per-texture choices take effect only when global KTX2 is enabled.
Quality and compatibility checks
ETC1S quality ranges from 1 to 255. UASTC encoding level ranges from 0 to 4, with Zstd level from 0 to 22. Higher encoding effort can increase conversion time; it is not a guarantee of a smaller file. Apply changes, compare fine details and lighting, and test the downloaded file in its target viewer. KTX2 requires support in that viewer; exclude textures or disable KTX2 if the destination does not support it.