2048 map on ipad

[kloveridge]

Realizing that a 2048 map is very expensive memory-wise, is there any kind of speed penalty using this size of a map on a iPad?

[ali31]

UDK supports culling, so the only speed penalty should be the map taking longer to load.

[Blade[UG]]

you mean texture map? try not to use 2048 textures unless absolutely necessary, i'd say. consider how much memory a 2048x2048 texture takes up. it's quite large.

[kloveridge]

Well, I'm solving a particular problem. Its a old problem for games. I have a large building (which happens to be the "star" of the level) that, if unwrapped in a 0.0-1.0 UV space would require a 8192x8192 map to have enough texel density to come off convincing. Obviously, not feasible.

So I've tried three different approaches.

Approach 1. Unwrapped it into four 1024x1024 maps. The trouble was, the texel density was still too blurry. Especially when the camera came close to the building.

Approach 2. Unwrapped six 1024x1024 maps. And reuse portions of the map for elements that were similar (like trim). The trouble with this was, it burned too many maps and the results were starting to feel a little generic. Also I hadn't used any normal maps.

Approach 3. Use a 2048x2048 map for the grunge/AO map which is unwrapped 0.0-1.0 space. But then use smaller 256 maps with high tesselation to achieve the texel density of the underlying texture. Even though the grunge is a little mushy, it seems to hold up well enough for stains and Ambient Occlusion. Plus, the normal maps can also be small. In the end, this seems to get the most bang for the buck for what I'm doing.

[darthviper107]

You're going to have some issues on iPad though

Normal maps run extremely slow, and the iPad in general is not very powerful.

[spyzor]

Why don't you seperate your building in modular mesh which will consume less textures?

For example, you do one window or on wall then you assemble everything. It will cost less texture

[Wraiyth]

But costs you in draw calls... every mesh/material is one draw call.

[seenooh]

Then use an LOD for that building. Only when you come close, the suitable texture should be applied on it. When you are far, use a lower resolution texture.

I think using a 2048 * 2048 texture can be useful also if you use it for multiple different meshes. For example, divide it into four sections, and each is used to texture a different mesh in your scene. This will save some drawcalls too.

[seenooh]

Normal maps run extremely slow, and the iPad in general is not very powerful.

Didn't the citadel demo do a good job with normal mapping?

[darthviper107]

Didn't the citadel demo do a good job with normal mapping?

On iPad it doesn't have normal mapping, parallax occlusion mapping, or specular highlights.

[seenooh]

You mean the device itself doesn't support those? Or there is a special version made for ipad where those features are not included?

Sorry I'm asking this as I don't have much experience in these platforms.

[darthviper107]

You mean the device itself doesn't support those? Or there is a special version made for ipad where those features are not included?

Sorry I'm asking this as I don't have much experience in these platforms.

There are device settings in UDK mobile, by default the iPad 1 does not have those features enabled (although it can actually do them). The reason is that with those features being used the performance goes down a lot. A game developer would have a hard time with the limitations with those features enabled (it really slows it down a lot) so that's why they are turned off by default.

iPad 2 can run them much much better though

[Davision]

Well, I'm solving a particular problem. Its a old problem for games. I have a large building (which happens to be the "star" of the level) that, if unwrapped in a 0.0-1.0 UV space would require a 8192x8192 map to have enough texel density to come off convincing. Obviously, not feasible.

So I've tried three different approaches.

Approach 1. Unwrapped it into four 1024x1024 maps. The trouble was, the texel density was still too blurry. Especially when the camera came close to the building.

Approach 2. Unwrapped six 1024x1024 maps. And reuse portions of the map for elements that were similar (like trim). The trouble with this was, it burned too many maps and the results were starting to feel a little generic. Also I hadn't used any normal maps.

Approach 3. Use a 2048x2048 map for the grunge/AO map which is unwrapped 0.0-1.0 space. But then use smaller 256 maps with high tesselation to achieve the texel density of the underlying texture. Even though the grunge is a little mushy, it seems to hold up well enough for stains and Ambient Occlusion. Plus, the normal maps can also be small. In the end, this seems to get the most bang for the buck for what I'm doing.

8192x8192 map is incredible huge, theres no current gen game that uses such textures except when you would use tech5 with their mega textures tech but even the developers that use that tech make the source textures much smaller and bake it together to big textures in the engine. 2048x2048 is still big for PS3/Xbox360. You should seriously look into building your assets modular. Look at the maps that come with the UDK and with what assets and textures they are build. Also, there is a tool in the UDK that helps you with making buildings modular, dont know the name right now.

[Bhrazz]

There is really no reason why 1 texture should wrap a whole building.

The best way to do what you want to do, is to have many textures. Lets say you want a 256X256 for brick, 1 512X512 for some concrete + windows + object+ trims etc...

you would get somewhere between 1024X1024 - 2048X2048 for your texture.

thats 1 draw call per textures. 1 draw call for the model. All your electricbox, pipes etc... props attached to the building, you want them merged to your model before exporting to UDK, thats less drawcall. ( I have done a building that is about 8000 units long and a 1024lightmap is doing a very nice job)

This way, you get maximum resolution for your building and maximum frame rate for you gameplay.

There is absolutely no reason to do a building the way your describe it unless you are doing a RTS (topview, LoL style ).


Hope it help, good luck!