Problem texturing a track for racing games

arkaneXXI

Hi. I'm trying to make a track for a racing game in 3ds Max. First I modeled and textured a segment of the track:


Then I duplicated it many times and attached it in a single mesh:



And finally I created a spline with the shape of the track and added the modifier Path Deform to the mesh of the road and picked the spline.


The problem that the texture gets very distorted in the corners.


The only way I know to solve this is to make a new UV for every segment of the track and texture it. But I think there must be a better way. Besides, do you recommend me to make the track in segments with small textures or make all in a single mesh but with a big texture?

Thanks!

kwyjibo

I don't use Max, but couldn't you just separate the UVs for the side sections into a different shell or make them a separate mesh entirely? That way, you can deal with them independently from the road section. Relax and straighten the uvs out into  long strips strips and place them over the texture so that the stripes tile over the length of the strip.

arkaneXXI

Thanks for the reply.

You mean to use a single texture for all the UVs, placing the clusters on the correct part of the texture like this?:


...but having the side sections and the road in two different meshes with two different textures?

That sounds cool, I'll try it now. Thanks again for the tip!

arkaneXXI

The problem is solved and the texture is finished now. But, for some reason I don't know, the texture is distorted in some edges.




Somebody knows why?

Eric Chadwick

Add more edges where you need them.

Use "Flow Connect", and Target Weld any unnecessary extra vertices.
http://help.autodesk.com/view/3DSMAX/2019/ENU/?guid=GUID-D07B4F5B-33AE-4544-A905-A52A678C7D64

arkaneXXI

Actually, I did that. I used the tool Flow Connect a lot. The topology is very clean already.

RN

Can you show the wires and UVs for that troubled part?

arkaneXXI

Sure, here they are (there are more troubled parts, but this is one):






It seems the problem happens in the closer curves because I'm using a rectangular UV. The problem is, if I don't use a rectangular UV, I need to make a texture for every segment and I think isn't nice to make 20 or 30 textures for every track.

Should I use a big texture for all the track or many textures for every segment?

I think is better to keep the track divided in segments for the culling, to don't render the segments that are very far or behind the cam.

Eric Chadwick

Just add more edges. You can't prevent rect UV distortion, but you can minimize it by adding more geometry. More vertices is relatively cheap.

arkaneXXI

I tried that and it just add more distortions. It's a problem on the UV, so I must relax the clusters instead keeping them rectangular. But if I do that, I'll need to make a texture for every segment of the track, because after being relaxed, the clusters won't fit with the current texture.

Eric Chadwick

Oh I see, Flow Connect only works with contiguous meshes, but your track curves are separate pieces.

So, you just have to edit the new edges by hand. Make that middle loop curve a bit more, instead of being linear.

RN

Okay, the same thing happens in Blender, it seems to have to do with mipmapping on the viewport.

If I turn Mipmapping off in the user preferences, it goes away.

Try it on 3dsmax, it's in Customize -> Preference -> Viewports -> Configure Driver -> MipMap Lookup -> None (I think only the OpenGL driver lets you tweak it).

When it's on, it gets worse the smaller you make a track segment or the more you tilt the view at a grazing angle towards the track. 

I'm not sure how it'll look in a game engine, probably the same.

arkaneXXI

I'll try that now. I just wanted to add, the error dissapear if I'm very close to it. So I think isn't a problem of the mapping.


Anyway, I'll ask to my programmer if the problem is also reproduced in the engine.

arkaneXXI

Changing the driver the problem is solved in the viewport, but not in the render.

Eric Chadwick

Check the Blur settings in the Bitmap Map within the material. 

arkaneXXI

Thanks. Yes. That solved the problem in the render too.


Now I'll try with a more detailed texture.

arkaneXXI

The problem is still visible in detailed textures but isn't so obvious as before. I think that's because the UV is all straight. But it's fine like that. Thanks for the help.

kwyjibo

The inner yellow line looks much smoother than the outer yellow line and middle white lines due to higher polygon density. It might be worth unifying the polygon density on the inner and outer sections of the track (ie. less vertices on the inner, more on the outer) so it doesn't standout so much.