View Full Version : How do I render bumpmaps that extend to infinity without getting texture buzz?

09-26-2005, 04:53 PM
I am rendering a bump mapped lake that extends to the horizon. My bump map gets very buzzy towards the horizon because of camera motion and bumpmap motion.

I remember hearing in a texturing tut on an earlier version of LW that there was a way to adjust anti-aliasing on textures as they receeded in depth just to avoid the problem of small details getting buzzy.

I have Mip Map to high, and the problem is visable even at medium antialias settings. I can't afford the render time to do it any higher.

I don't think that fading the texture is possible because the camera is moving in x and z, but I will admit that I'm a bit fuzzy on how to set that up. Besides, if I were to simply fade the texture off in distance the reflection on the water would simply be like a mirror at the horizon, which isn't what happens in reality.

Any Ideas?

PS. I ran across an Ansiotropic setting somewhere that sounded like it might address this issue but I can't find it again.

Any Ideas appreciated.



09-26-2005, 05:16 PM
Try turning on Adaptive Sampling in the Camera properties. Then specify an amount in the threshold entry. Adaptive Sampling allows Lightwave to only apply the anti-aliasing solution to specific areas of a frame. Thus you can specify the areas that are fuzzy without having to wait as long as a fully anti-aliased render. I'm not sure if that would help, but hope it helps and good luck.

- Rachel D. :lwicon:

09-26-2005, 05:42 PM
You can apply a gradient set to 'distance to camera' and set the key at 0 to have alpha 0. Then set a key at a distance at which you want the bump to have faded off and set that to 50% so the gradient fades from transparent to grey. then as the cameramoves towards and away from your object, the bump will disappear at the same distance from the camera.

09-26-2005, 07:55 PM
Hi Dodgy,

I am missing something.

I am in the surface editor under Bump map.

Layer # 1 is my bump map. Blending mode is set to normal.

Layer # 2 is my gradient set to "Distance to Camera". My blending mode is "texture displacement".

I have a grade going from white to transparent mid-graph But I see no affect. No Fall-off of texture.

What details am I missing?


09-26-2005, 10:03 PM
The gradient layer goes on top of the map layer, with it's blend mode set to Alpha. To keep things simple, use a black to white grad, leave the alpha of the keys at 100%. The number at the bottom of the grad is the furthest distance, so set that value out on the horizon somewhere. At 0, the top of the grad, start with black, and put a key somewhere in the middle also black, because you probably don't want to start fading the bump 5 meters from the camera, and a white key out at the end. You'll have to mess with the settings to get the look you want.

I believe what Firegirl was saying was that you could use higher anti-aliasing, and adjust the adaptive threshold to speed it up a little. While I'm not a fan of adaptive, that could work. Turning on Enhanced will definitely help here too.

09-26-2005, 10:23 PM
Silly me, the online documentation states that setting a layer to Alpha makes it an Alpha channel to the preceeding layer. To me that implys that the Gradation is UNDER the layer that you want to affect.

Thanks for saving me lots of headbanging until I hit upon that combination.