Celestia Forums

Why is it that when I use a 4k texture that is in .PNG format my computer explodes into molten lava but when I use an 8k texture that is .DDS it runs nice and smooth?

Reiko wrote:Why is it that when I use a 4k texture that is in .PNG format my computer explodes into molten lava but when I use an 8k texture that is .DDS it runs nice and smooth?

Because unlike PNG, DDS format has HARDWARE support from your graphics card processor (GPU)! It is unpacked this way in almost no time. Remember how slow Celestia would run, if you had to use software OpenGL (called Mesa) rather than it's hardware implementation! In software OpenGL mode you would get at best 1 fps (!) when Celestia runs.


Fridger

Oh I see, thanks! Now I will have to redo all of my planet textures I've been working on into larger .DDS format.

Reiko wrote:Oh I see, thanks! Now I will have to redo all of my planet textures I've been working on into larger .DDS format.

Just download and install the binary NVIDIA-texture-tools 2 package from here
(it's simple, by means of an installer)
http://developer.nvidia.com/object/texture_tools.html
The download is near the bottom of the page, a bit hard to see...

There is a nice DDS viewer from NVIDIA, too, called WTV (aka Windows Texture Viewer)
Install it from here
http://developer.nvidia.com/object/wind ... iewer.html

If you got a RGB colored *.png texture, tex.png, you can convert it to dds simply with this command typed in at your Windows console:

nvcompress -bc1 tex.png

If you have also an alpha channel (A), carrying spec or transparency info, i.e. if your texture is RGBA, then the command is

nvcompress -bc2 tex.png

In the same directory, you will find then a DDS file, tex.dds.

Note that for dds compression, the width AND height of your texture must be dividable by 4!!!

Good luck,
Fridger

Thank you for the tips and links.

--- edit ---

john Van Vliet wrote:even though this is a dds post you mentioned a 4 k png file .If you resave it in gimp and use no compression ( that is set to 0 - the default is 6 , mine are at 4 and some set it to 9 ) then you might get up to 4x faster loading speed

9 indeed should not been used, For the PNG output in my texture tools I also follow that philosopy. 4 is an optimal compromise. Even 1 is already compressed surprisingly much.

Fridger