texture_accept_untiled

High-resolution untiled texture maps are very inefficient to render because they must be loaded entirely into memory as soon as the renderer needs to access the first texel. When this flag is disabled, any attempt at loading an untiled file will produce an error and abort the renderer.

texture_accept_unmipped

High-resolution unmipped texture maps are very inefficient to render because the highest resolution level must be loaded into memory regardless of the distance rather than a lower resolution level. When this flag is disabled, any attempt at loading an unmipped file will produce an error and abort the renderer.

texture_automip

If a texture map file is not natively mipmapped (e.g. a JPEG file), enabling this option will trigger the generation of a mipmap on demand. The output will be stored in memory and put in the global texture cache. This mipmap generation increases render time, especially for scenes with many high-resolution textures. To avoid this performance slowdown, it is recommended to use texture file formats that natively support mipmapping (such as TIFF and EXR), where the mipmaps are preprocessed before the render and stored in the file. This preprocessing can be done with the maketx utility.

Disabling 'options.texture_automip' will result in unfiltered non-mipmapped textures.

texture_autotile

If a texture map file is stored in scanline mode (e.g. a JPEG file), enabling this option will trigger the generation of tiles on demand. The output will be stored in memory and put in the global texture cache. This process increases render time, especially for scenes with many high-resolution textures. To avoid this performance slowdown, it is recommended to use texture file formats that natively support tile mode (such as TIFF and EXR). You can create tile textures with the maketx utility.

texture_conservative_lookups

Determines the texture filter width policy. It will err on the side of softer texture look-up

texture_failure_retries

When opening or reading a tile from a texture fails, Arnold's texture system will pause and try again, up to the texture_failure_retries value before returning a failure. This is meant to address spooky disk or network failures. The default is zero, meaning that failures of open or tile reading will immediately return as a failure.

texture_max_memory_MB

The maximum amount of memory to be used for texture caching. Arnold uses a tile-based cache with an LRU (Least Recently Used) type algorithm, where the least recently used tiles are discarded when the texture cache is full.

texture_max_open_files

The maximum number of files that the texture system keeps open at any given time to avoid excessive closing and re-opening of files when caching individual texture tiles. Increasing this number may result in slightly better texture caching performance. On the other hand, if this value is higher than the maximum number of concurrently open files supported by the operating system (e.g. Linux vs Windows), some texture lookups may fail and return red. This is set by default to 0, which means that the maximum number of texture files that can be simultaneously opened is automatically computed by Arnold using a heuristic that tries to guess what the optimal number would be for each particular machine. We expect that the majority of users will be able to leave this at 0 and get the best performance.

texture_per_file_stats

Enables useful per texture statistics, with time spent on textures queries, the amount of texture data read, memory consumption, etc.

texture_max_sharpen

texture_max_sharpen is used to improve the quality of textures so that they do not appear blurry. As texture_max_sharpen is increased, textures lookups occur from higher-res mipmap levels. The theoretical optimal value of texture_max_sharpen is to set it to AtOptions::AA_samples. The reason we do not have it set to this by default is that querying the higher-res mipmap levels also results in an increase in texture data that must be read into Arnold. This can be an issue when there are GBs of textures being read in. Instead, we allow the tradeoff for slightly blurrier textures to be used in exchange for substantial savings in texture data read. The default setting of texture_max_sharpen=1 will often appear slightly blurry. Setting it to around 1.5 will result in significantly sharper textures which in most cases are almost indistinguishable from the optimal setting. In some situations, even higher quality textures might be required and so higher values should be used. Since using a value larger than AtOptions::AA_samples is not a good idea since aliasing will occur, we clamp values larger than this to AA_samples. This can be used to your advantage if you always want the highest quality settings to be used; just set texture_max_sharpen to an extremely large value, such as 9999, so that it will always end up being clamped down to AA_samples.

 

 

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