Texture Size for a Ship?

[Japal911]

So I've created a Nova class ship and now am at the texture stage. I've seperated the hull into two parts- upper and lower, and I've also mapped the polygons. Now for the question- How big of a texture should I use for the upper/ lower half of the ship- 1000 pixels, 1500 pixels.....? I'm wondering because the bigger the texture- the more ram the rendering takes and I'd rather use as little ram as possible. Thanks!

[JeffrySG]

It all depends on how close you will get to the ship in the renders, and how large the renders will be. Generally you don't want any part of the texture to be bigger than a 1:1 relationship to the final render. If it's going to be moving fast you might be able to get away with a lower res texture also. It might be good to create the texture much higher, say 4096x4096 and then create a few lower res versions. You can always go back to the higher res one if you need. But you can render with the lower res ones if you can get away with it.

[Coolhand]

So far as RAM usage goes, i think you're always best off sticking to powers of 2, so 1024x1024, 2028x2048, etc. In terms of how big a texture you need, you should work out how close you need the camera to get to the ship and what resolution you want to render at, you don't really want your textures to look stretched or to be able to see the pixels in your texture, so one pixel of texture shouldn't occupy more than one pixel in your render, so make the textures big enough to allow for this. It's up to you to decide how small a texture you can get away with.

[Japal911]

Okay- Thanks. Its really great to get some different opinions on the subject. Thanks!

[Sastrei]

Don't forget you can use non-square textures, like 1024x2048 or 512x1024 for example. Useful if your ship's main hull is rather long.

-Stefan-

[Coolhand]

I don't think thats a very good suggestion, i've always been told that that wastes ram, so a 1024x2048 map will use the same amount of memory as a 2048x2048 since computers don't like to work with anything other than square images... your image file size will be smaller, but once it's loaded into memory it apparently treats it as a square, so you're effectively wasting 2 whole 1024x1024 maps.

[Sphynx]

In regards to computers wanting it, that's slightly innacurate, but Coolhand is perfectly correct - most algorithms used for image processing by the software involved find it much easier to use square maps due to matrix calculations and the like. It's just the way that CG software has evolved over the years.

Also remember that most (not all) applications like raw-type image files - so a JPG image on disk will use less storage space, but needs to be decompressed each time it gets loaded into memory. Usually (but again, not always), something like a Targa image can actually speed up processing of the textures even though it uses a huge amount more storage space on disk.

[Japal911]

Great suggestion- I'll try out the using Targa images.

[Ndege]

Like many folks have mentioned power of 2 image size (256x256, 1024x1024 2048x2048, et al.) can be considered a good scene optimization practice.

Another consideration is map size as a function of your final image size. A good rule of thumb here is to have a map be at least twice the resolution of the final rendered size. Meaning, if you have a object that is going to be taking up roughly 256x256 of your final image, it would be wise to give it a texture map of at least 512x512. This gives your antialiasing and sampling algorithms more information to use, resulting in better final image quality. Garbage in, garbage out still applies, so Sphynx' suggestion of staying away from JPG images applies here as well. The compression artifacts will impact your map quality going into the render environment giving you a lower quality output.

Further research here

[Japal911]

Wow, incredibly helpful. Thanks!