The more modern BC4-7 formats should generally be avoided for now since the older Renegade-compatible W3D engine can't load them at all, W3D 5.0 ( APB, AR and BFD) can't load them yet (though afaik it would be trivial to add support) and most importantly, 3ds Max and many other programs cannot open them ( BCn App Support). Missing in this table is a particular trick for using DXT5 for better quality normal or bump maps explained here, also called DXT5nm or DXT5-xGxR and has direct support by a few tools (e.g. A nice overview of features and use cases for all BCn formats can be found here. This means that BC1 should be used where applicable to save memory, don't forget the 1 bit of alpha comes (almost) free! BC2 use cases are rare, usually you probably want BC3. The data rate is constant regardless of image content: 4 bits per pixel for BC1 and BC4 and 8 bits per pixel for every other format. Use BC3/DXT5 for RGBA textures with smooth interpolated alpha (use this over BC2 unless you're certain) Use BC2/DXT3 for RGBA textures with discrete "hard" alpha transitions (this format has 4 bits of alpha per pixel, so 16 different levels of transparency) Use BC1/DXT1 for pure RGB textures or hard "cut outs" which only need one bit of alpha (fully opaque or fully transparent note that some tools have a separate mode for this called "DXT1A") The DXT-Formats mostly differ in their handling of the alpha channel (usually used for transparency). The key ingredient for this to work is that the format is made out of independent 4x4 blocks of pixels that can be decompressed individually instead of the entire texture at once.Ī more thorough look at the details of the compression formats can be found here: The decompression is implemented directly in hardware and happens transparently on memory access. With hundreds of megabytes of textures this adds up quickly and allows us to improve performance (less memory bandwidth used) and target lower end/older GPUs with less VRAM. The advantage of these compression formats compared to something more common like JPEG is that they can be uploaded to the GPU directly and always stay fully compressed in GPU memory. Each of these have their own use cases and advantages, so higher numbers are not just "better" versions.
![ac3d plugin dds texture ac3d plugin dds texture](https://www.inivis.com/images/features/views.gif)
These are also called BC1/2/3 ("Block Compression") respectively.
![ac3d plugin dds texture ac3d plugin dds texture](http://www.inivis.com/images/site/AC3Dlogot86.png)
There are 3 major compression formats defined in the Direct3D 6 standard: DXT1, DXT3 and DXT5.
#Ac3d plugin dds texture how to
In this tutorial I want to teach you how to get the best quality out of your textures when compressing them.ĭDS is a container format designed for texture data and can have different amounts of compression applied (including none).