PS3 compression.

[Kb-Smoker]

I Send some questions to the creators of the Terrain Engine (MR. Barry Minor) on compression I saw with the SPE:

->How processing of textures was made (which amount equivalent in used MB in the TRE ?) and which form of applied compression?

->Mr. Barry Minor : Textures are bilinear filtered and provide the base material color for the lighting equations. The textures are stored in an uncompresses 16 bit (5/6/5) format in memory and are converted to single precision floating point via the SPEs before texture filtering. Most of our terrain data sets use several hundred megabytes of texture memory.

I have curiosity to know which processing capacity in SPE for tax compressions in textures (CLUT = 4:1? ) therefore each time more gives to importance the textures ,and more still in the next generation (Unreal Engine 3.0).


( I have some "impression" the use of the SPE can bring taxes of very superior compressions than current techniques - > S3tc/DXTC; 3Dc etc).

This guy posted this here and i knew you guys could makes some sense out of it.

 

[MechanizedDeath]

RSX should support some texture compression. MOST as a matter of fact. Not sure about normal map compression. But I don't see what advantage there will be to having SPEs handling texture decompression. This isn't the PS2. The PS3's GPU will handle decompression. Unless Sony offloaded that to the CPU in order to free up even more trannies for the GPU...but that would just be idiotic IMO. That would kill that bandwidth to the GPU IMO. PEACE.

 

[jvd]

RSX should support some texture compression. MOST as a matter of fact. Not sure about normal map compression. But I don't see what advantage there will be to having SPEs handling texture decompression. This isn't the PS2. The PS3's GPU will handle decompression. Unless Sony offloaded that to the CPU in order to free up even more trannies for the GPU...but that would just be idiotic IMO. That would kill that bandwidth to the GPU IMO. PEACE.

Well the rsx if based on the g70 will do dxtc 1-5 of course . It should also be able to do the 3Dc hack that nvidia came up with . NOt quite sure on how it works however.

 

[robofunk]

This has nothing to do with game engines this is that guy who did that raytracing terrain engine using Cell only. http://www.research.ibm.com/cell/whitepapers/TRE.pdf

Got me thinking though. It could be possible to store textures as JPEG2000 (or some other advanced image compression) on the game disc then convert the textures to S3tc/DXTC; 3Dc etc. when the game is loading into main memory. GPUs could probably even be programed to help with the conversion. Microsoft/Sony could even provide it as optional middleware in the SDK.

 

[Simon F]

Got me thinking though. It could be possible to store textures as JPEG2000 (or some other advanced image compression) on the game disc then convert the textures to S3tc/DXTC; 3Dc etc. when the game is loading into main memory.

That would be rather time consuming. A far simpler, quicker and probably nearly as effective method, would be to run a generic compression/decompression algorithm (eg as used in gzip or bzip2) over the S3/DXTC data. You could, possibly, also do another step of computing the differences of the base colours from block to block to gain a little extra efficiency.

 

[Rolf N]

This guy posted this here and i knew you guys could makes some sense out of it.

This is no compression at all.
The data is stored as a 16bit integer per texel in memory, with five bits allocated for red and blue components and six bits for green. This is a very common uncompressed texture format.

This data gets converted to 32 bit floating point per component for processing. Probably because it's much easier to operate on floats than on partitions of packed bit vector. This can be done in software, and it's much more likely to be done in software than to expect that an SPE somehow has dedicated hardware to perform this conversion.

An SPE is just a programmable processor with a fairly general purpose instruction set. Of course you can do all sorts of fancy stuff on there, but like with any other processor it is going to be done in software and is going to cost cycles. Likewise an SPE can certainly decompress DXT1 textures for a cost.

I really don't understand what the fuzz is all about.