Hi there again.
Currently I'm looking for ways to optimize rendering and/or enhance the visual richness at the same time.
So I was thinking of these:

1. Can a terrain be rendered with more than 3 textures? (even by custom shaders). I feel the need for extra detail.

2. Can a terrain have a normal map?

3. Can a terrain benefit of parallax?

4. Can someone please enlighten me about the light map of a (large) terrain - is it one large texture? If so, how doesn't it cripple the performance (memory)?
I'm asking this also because I have an interest in using large textures for different purposes.

1. Yes
2. Yes
3. Yes
4. Yes. Although it might use another UV set. I don't see how memory is a problem for performance. As long as you don't exceeds the users VRAM there is no drawback in using more memory.

Thanks Uhrwerk. But come on, would you care to tell me more - where to look for the first 3?
Not sure 100% for 4 (more like 85 ) but
A. lo mem = textures swapping more often
B. VRAM is slower even than system memory, albeit video mem.
C. I guess rendering time increases with texture size.
I'd be happy to be wrong.
I thought of using large transparent sprites to somehow simulate volumetric light (stop laughing). I suck at shaders.

You didn't asked where to get those tell us more about your specifications and you might get fruitful answers, directions and maybe, even maybe links



If you want to have a multitexturing shader, you have to sample for each pixel N colors for N mixed textures plus one or more texture samples for the blendmap, plus one sample for a lightmap, if you use one. If you use normalmaps, things might get complicated and you need two samples for each texture (1 texture and 1 normalmap fetch).

If you want one single texture fetch for color + normal, you could use a two-channel colorspace encoding scheme like RG color space (Technicolor, see Wikipedia) and only X and Y component of the normal, while you decode the color and the missing Z-component of the normal in the fragment shader.

Other than texture samples, one drawback is also the amount of data you push through your GPU card. The bigger the textures, the more data is going back and forth, and, yeah, that could reduce performance as well.

BUT, this depends only on your specifications.

Tell us.

Thanks for answering.
I've read the manual (most of it) like half a year - a year ago. I followed the tutorials but I couldn't find anything about terrain normal mapping. I *guess* NM and parallax for terrain entities are not native to 3DGS which wouldn't be a problem if I could find anywhere custom shaders to d/l. Still it would have been best if I didn't need to add/write extra shaders.
About specs, I don't understand what you mean, I simply want to make a RTS and find a good balance of speed/no of textures per terrain, to use. I want small objects to be normal mapped and parallaxed instead of entities.

Here is a terrain multitexture shader with 3 textures + normal maps, and a lightmap, and sun + 2 dynamic lights, and fog support:

link

Wow. That is a glass of water to a dying thirsty man! I'll reply there.