Product Details

How OAT Texture Supercompression Works

OAT takes lossless source textures (i.e., PNG) and produces supercompressed texture files that can be decompressed into intended block texture formats.

Details Preservation and Fidelity

OAT Texture Supercompression targets a high-quality, near-lossless range for BC7 and for ASTC. It preserves luminance and contrast, prevents hue shifts and protects flat regions and gradients. It has a high correlation of requested and produced fidelity.

Perceptual model is crucial when trading off size and fidelity. PSNR (RMSE) is too naive and ignores low frequency details. Luma weighting mistreats chroma, produces hue artifacts Neither sRGB nor YCbCr is euclidean, while Oklab is very close. And Almost all content needs structural feature preservation.

We evaluate the fidelity of the output using SSIMULACRA2, a respected perceptual fidelity metric that shows very high correlation with scores obtained through human visual inspection. A score above 85 means excellent visual quality: no distortion is perceptible to the human eye from normal viewing distances. In all the charts used in this website, a SSIMULACRA2 score of 90 is used for fidelity unless otherwise specified.

For both the BCn and ASTC products, the user is able to select a target level (called lambda metric) to achieve a higher or lower fidelity as needed.

RDO Mode

OAT includes an alternative RDO mode which is tuned to maximize downstream compressibility with formats such as zlib or Kraken-class compressors, producing texture data that achieves smaller package sizes while preserving the target GPU block formats.

Crucially, this alternative RDO mode is fully compatible with the dedicated hardware decompression pipelines on Xbox and PlayStation. On PlayStation, it pairs naturally with hardware-accelerated Kraken decompression; on Xbox, it aligns with the platform's hardware-accelerated general-purpose decompression paths. In both cases, OAT enables textures to be stored in a more compact form, decompressed by fixed-function hardware during streaming, and delivered to the VRAM without incurring runtime CPU or GPU cost. The result is faster load times, reduced I/O pressure, and higher compression efficiency without requiring changes to runtime code or GPU formats.

GPU/CPU Decompression

OAT offers unprecedented decompression performance through GPU compute shaders, as well as state-of-the-art pure CPU decompressors, providing developers the flexibility to decide at runtime, to achieve optimum performance based on resource constraints of the target devices.

GPU decompression is especially impactful for CPU constrained applications, such as simulation and physics heavy games (e.g., flight simulators, city-building games…).

OAT does GPU decompression using single pass HLSL compute shaders that run on any compute-capable platform.

VRAM Amplification

GPU-driven decompression unlocks an emerging capability: OAT can act as a VRAM multiplier, enabling developers to store 4X the amount of textures in VRAM supercompressed, in an intermediate pool. These supercompressed textures would then be decompressed when needed just-in-time, using negligible GPU compute and in a negligible time span. With the incredible decompression throughput (102 GB/s on RTX 3060, 208 GB/s on RTX 3080), OAT is capable of decompressing several high-resolution textures every frame.

Fast CPU Mode

OAT also has a fast mode, granting 3× decompression speed while sacrificing file size but still yielding 5% smaller files vs Oodle+Kraken. Fast mode can be selected per-asset at build time.

OAT vs Oodle Texture + Oodle Kraken

OAT is a direct, drop-in replacement for the Oodle Texture + Oodle Kraken pipeline, providing superior compression ratios and GPU-driven decompression capabilities.

OAT enables 25% more content within the same size and fidelity constraints as Oodle, beating its CPU decompression speed at a significantly higher compression ratio and uniquely offering pure GPU-driven decompression (which can be decided at runtime).

Performance Benchmark

Our public benchmark data set consists of 32 pristine, lossless 4K color textures from ASWF Digital Production Example Library, supercompressed with OAT BC7 using a near-lossless preset, and decompressed to PNG. We evaluate the fidelity of the output using SSIMULACRA2.