DDS vs Ace

[James Collins]

Using forest regions and using the "load dds in preference of ace" option I get this picture below.



The alpha seems to be cutting out too much of the tree?

Below is the same exact tree using ace instead.



Same exact file, but one is saved as an dds and one as an ace. I have created the dds from an ace and I have created the dds from the original picture and saving direct to a dds using dxtbmp.

[rdamurphy]

I like the top one better...

Robert

[OTTODAD]

After saving an ACE file to TGA with TGATool2 it can the be saved easily to DDS using Paint.NET !

[gkhager]

I prefer the top one as well, it just appears more 'realistic' to me.

[James Collins]

I like the top one better...

Robert

Ok, here are some of the same trees in a different location, Ill compare dds to ace. DDS seems to look fine up close, but even then the tree is not nearly as full as it is with an ace file.





As we back the camera away you can see with the dds texture is starts to lose a lot of its fullness about midway in the tree. Trees up close are ace files and distant trees are the dds.





More of the same at a further distance. Trees up close are ace files and distant trees are the dds.





Lets try track level, or close to it. Trees up close are ace and trees further down track are dds.

[James Collins]

After saving an ACE file to TGA with TGATool2 it can the be saved easily to DDS using Paint.NET !

Doesnt saving to ace degrade the quality of the texture?

[gkhager]

James,

I see what you are saying, but I also think that it comes down to personal preferance. I sort of like the 'thinner' look to the DDS textures. As you can see in the final ACE picture, there is an obvious line showing up in the trees due to their placement, that is 'softened' in the DDS version.

Geoff

PS> I can also see how the DDS 'thinness' (if that's a word?!?) would be more of a negative in a deep forest type of setting.

[EldoradoRailroad]

From http://www.fsdeveloper.com/wiki/inde...sion_explained

DXT3
The colour information in DXT3 is saved similar to the DXT1 format without an alpha channel. So a palette of 4 colours is used to represent 16 pixels of the texture. But the alpha information is stored with 4 bit in the DXT3 format. That means that in total 128 bit are used for the 16 pixels (32 for the palette, 32 for the colour indices and 64 for the alpha information). So this results in a compression ratio of 1:4.

Because the alpha information is stored in 4 bit, the smallest step in the alpha value that can be stored is 16. This means that very smooth transitions in the alpha channel can not be stored in the DXT3 format.

DXT5

The DXT5 formats differs from the DXT3 format in the way the alpha information is saved. The colour information is stored in the same way.

For the alpha information it uses a palette, similar to the way the colour information is also stored. This palette contains a minimum and maximum alpha value. Then 6 other alpha values are interpolated between this minimum and maximum. This thus allows more gradual changes of the alpha value.

A second variant does interpolate only 4 other alpha values between the minimum and maximum, but also adds an alpha value of 0 and 1 (for fully transparent and not transparent). For some textures this might give better results.

In dxtbmp what compression method did you use? If the original .ace is not using a 1 bit alpha channel (which is what it looks like in your screen caps) using DXT3 instead of DXT5 will make a difference in the result. The thinning out will most likely be certain levels of alpha being tossed out during the compression with dxtbmp.

Try both DXT3 and DXT5 and see what the results are....better still post the screen caps of just the .ace and .dds files from your paint program (the texture AND the alpha channel).

Just my guess

[scottb613]

Hi Folks,

I haven't had the opportunity to check myself - but - perhaps the way DXT5 handles Alpha's differently - could possibly fix the alpha sorting issue with signals - such as not displaying smoke when looking through the alpha ???

[OTTODAD]

Doesnt saving to ace degrade the quality of the texture?

I am saving the loaded into TGATool2 ACE into TGA because Paint.NET can not load ACE files and using TGA also includes the ACE's Alpha channel if it has one !