I wanted to know why fpscr is use dds file format and not another format like png?
the game "The Escape" weighs 540MB and the dds files weighs more than 400 MB.
If we convert them to another format such as png It will weigh about 100 MB.
Is this possible???

I have always wondered this myself. Unreal engine accepts .png and in comparison, the files size is tiny. Plus, png is a lossless format. I created some atlas textures at a resolution of 4096x4096 and each image was 64Mb. There are 4 images!

If anyone more experienced with this could answer, please chip in, I would really like to know as well.

Cheers

Jay.

I think this is more a legacy thing that has never been changed, right from the beginning DBPro has supported DDS as it is the DirectX format used for textures since DirectX 7 and the texture loader is in the DirectX SDK. I think that with DirectX 11 and onwards you can have multiple textures inside one DDS file allowing some stuff that PNG can't do.



Did a bit of digging and found the following points:

- DDS is quicker to load in VRAM than PNG, due to no need to decode

- DDS is smaller when stored in VRAM

- The tradeoff is you have a large file size on disk to cut down the time to load in to VRAM

- DDS is designed for use in game engines, PNG isn't. Why not use the format actually designed for this purpose.



I don't see any reason why PNG can't be used now instead of DDS. In-fact maybe my memory is playing tricks on me... but I can remember PNG textures working in FPSC X9, maybe they do work in FPSCR as well.



EDIT: While I was editing this I saw Tattie has posted a similar answer, his also answers this similarly.

PNG files look like they are smaller, they are only smaller on your harddrive. Once loaded onto the GPU they are between 4 and 6 times bigger than the same texture compressed using DXT1 or DXT5



Also dds are good, because they are used directly by the GPU, and are not decoded like PNG or JPEG

DDS is sent compressed to the GPU memory pending, which DTX format you use. Then there is other, benefits additional channel support, cube mapping, 3d voxel support, native mipmaps ect.Where as PNG lacks native support, PNG will also degrade GPU preformance.

DDS format used in the correct manner will allow for a 4096 x 4096 texture at about 22mb, DTX 5, without transparency. DDS was created with game development at it's core.

They do work still in Reloaded, actually, I have some old assets that used .pngs and I never bothered to convert them to .dds. They don't have normal or specular maps though so I don't know if those would work.

I think it was Doom 3 that set the standard for normal mapping dds files.....
Its been like it ever since then that I remember..

Unless the engine stores them in DXT compressed format on the GPU, which is entirely up to the engine to do that. It really doesn't matter what format you load the image from, it's how the image is stored on the GPU in texture memory. I think the biggest deal is that DDS is not only already pre-compressed in the format that the GPU needs, but also has the mip-maps pre-calculated as well, which takes additional time if loading from other formats.

Just look up mipmap in wikipedia and you will see the main reasons they are useful.

.dds loads faster and can be compressed in acceptable on-disk file size!

It also supports transparency and layers. ... so its a decent format. The only downside is less support in traditional image-editing software.







-Wolf