Max texture size for terrain

Does anyone know if there is a limit as to how big/detailed the texture for a terrain can be? From what I understand the bigger the texture vs the actual size of the terrain the more detailed it tends to be. So if I created a terrain lets just say 1280 x 1280 could a texture map be 12,800 x 12,800? Also if that is possible what terrain program allows this and would it make a difference in MED? WED? In game?

Texture map of size 12800 * 12800 > NO WAY!

On today's graphics cards the maximum texture size is usually 4096 * 4096.

ATI radeon > 2048
Geforce > 4096

I guess it is possible to make a texture that big but the RAM requirements are phenominal!!!

Here are some RAM (in MegaBytes) requirements for single textures >>>

Texture Size -- 16 bit -- 24 bit -- 32 bit

1024 -- 2 -- 3 -- 4
2048 -- 8 -- 12 -- 16
4096 -- 32 -- 48 -- 64
8192 -- 128 -- 192 -- 256
16384 -- 512 -- 768 -- 1024

So your 12800 texture will use just under a GB of RAM...so forget it.

Just experiment with UV tiling or detail mapping.

Tables taken from > http://www.vterrain.org/LargeTextures/

I agree with most of what DJBMASTER says, would'nt dare anything else being a Bruce Lee fan too. However, I did try to push the GS system and was able to load a 8192x8192 terrain map on an unchunked 129x129 vertices terrain. It took a while to load, less than a minute though. Didn't try larger texture than that. I used a nvidia card with 128 meg, so it probably used a bit of virtual memory too. Not sure if it is really usable in a game at this point with currently available hardware. Just say that I loaded it and moved around the terrain a bit without problems.

cheers,

I appreciate the words of wisdom you kind folk have granted me. I didn't think anything that big would work. I have a radeon so I guess 2048 is my max. Oh and tindust did the terrain look noticeably different or more detailed just wondering?

To answer your question, the terrain shows the details of the texture just fine with the build-in antialiasing (pixel blurring, can be turned off). In the example below I used a 8192 x 8192 texture map in the form of a .tga file loaded through an action script assigned to the unchunked 129x129 terrain. The texture file was loaded at startup. A nexus of 240 mb was assigned to the engine. (The texture file was a whopping 192 mb alone).

testimage1 shows a closeup of the texture pattern as shown in PaintShop Pro:



testimage2 shows the resulting terrain with the texture applied and antialiasing turned on:



The loading time for the terrain with this texture was over 4 min and the computer was obviously croaking under the burdon. Background music that usually starts up right away stopped a number of times until the level had loaded. After that everything worked just fine including music, player mobility and physics.

The main difficulty using this size terrain texture may be with making the texture in the first place. Graphics programs that can handle these textures well are few. PaintShop had noticable difficulties with this texture and the image files could not be saved as .dds or .hdr, at least not with the nvidia plugin used. I would not dare to think about what would happen if you try to use and work with original BlueMarble World images of 21600 x 21600. Still, with the right hardware it should be possible.

cheers,

I originally thought that there might be a good reason to having a massive texture image. So far I'm thinking that is not the case. Too much of a good thing I suppose. Looks nice from a distance but I can't really tell a difference from this and a map not as large.

Right, better to use chunked terrains, or even better small subterrains and models for a more detailed terrain. That will give you as much details as you want. Only depends on the amount of work you care to put into it.

edit: Then of course you can also use fixed pipeline shaders with tiled terrain textures to improve details.

What do you mean by "small subterrains and models for a more detailed terrain" it didn't quite click?

Well, you can use any model and use it as terrain structure like cliffs, rocks, plants, or whatever. The model can be quite detailed both in structure and its texture. Make a big model and decrease its size when you assemble the level to increase the appearance of detail. Same goes for using hmp terrain files. You can spread out a few small terrains with good textures on top of the main terrain, decrease their sizes to get really high detail much the same as you do models above. There is nothing that limits you to use only one terrain entity. Read about the differences of hmp and mdl files in the manual. Just make them passable if necessary. Only imagination is your limit.

If you are not very good with modelling but are fairly ok with programming then check out some of the other ways to make more detail on terrains such as shaders, Fixed Function Pipeline, Normal Mapping, Post processing, etc...

They are not as easy as standard code and require a bit of rendering knowledge, but shouldn't be too hard to pickup.

Check out the shader workshop on the download's page. Search for terms like normal and bump.