Attached is an image that has bump mapping on. The shader is pretty simple. Color channel is white and bump has a brick shader on it. The following message has the bump channel not rendered and is closer to what I expect. The object is just a simple vertex object. Is this a known issue. Has anyone else hit this situation? I'm using Carrara 4 on a windows machine.

Now the image without bump mapping. Something much closer to what I was expecting to see instead of the dark side conversion.

Is Indirect Light checked on? I've had a similar issue using GI, when light comes from an oddly shaped object with a glow channel.... holly

I've rendered with GI/indirect lighting and without. Unfortunately doesn't appear to make a difference. I'll try some other render options to see if they help. I also tried flipping normals in the vertex editor to see if that was the issue. Didn't appear to make a difference though. :/

What happens if you invert the bump?

Tried that just now. The result looks like the image with no bump mapping which really doesn't make a hell of a lot os sense to me.

Further investigation... Reconfirmed that it does happen with GI turned off. For a second there I thought I'd be making a fool of myself.

Decided to try a different shader instead of brick. Veloute tools' 2D gradient worked rather well. Although I was looking for a slightly more understated effect than the one it gave me. I couldn't make the transition 'fine' enough.

I tried Anything Grooves on the beast but it made a hash of the mesh. Also, to get the understated look that I'm gunning for, the UV sampling would really need to be cranked up and that would make a huge mesh or a long time to calculate. Anyway, the generated mesh was unusable so the point is moot.

Ended up going with the following formula

a = u * 2;
a = a * 13;
a = mod(a, 1);
b = ((0.01 < a && a < 0.99) ? 1 : 0.5);
value = b;

And found out that formulae also don't behave as you'd expect in the bump channel. Not as hideous as the brick but not really close to what I expected from seeing the same formula shader in the color channel. Sigh, looks like I'll just leave it part of the color channel and hope that it'll be enough. If not then I'll compromise and use the veloute 2D gradient.

Thanks

Message edited on: 04/15/2005 00:43

Really doesn't make a lot of sense. How posting a shot of the original shader? You are using Veloute? 1 or 2?

Ok some things: -Interpolate..on or off? Turn it off. -Lights, what settings do you have for shadows? And how many lights do you have, positions etc. -Shadow and object quality set at what in rendering settings? -Full raytrace on? -Antialias setting? Any actual details about scene setup and rendering settings would help. It not the shader that is the issue. (I don't think) Brian

I have veloute 1. I'll try to reduce the scene and post it here. Currently the scene is 57MB. That's a tad much. ;) Render settings are irrelevant. GI, no GI, ray tracing, no ray tracing, pixel accuracy for shadows, object etc. do no change the fact that the arches are displayed improperly. There are 2 lights and they are roughly close together near the center of the four visible pillars. Total intensity amounts to 100%. It should all become evident (I hope) when I post the carrara file. It could well be that the vertex model for the arch is partly responsible for the problem but for the most part it looks fine to me.

Have textures saved internally? Unless necessary, remove textures internally. You can email the file to me at brian @ vizualds.com

Attached Link: http://members.shaw.ca/zekaric/arch.zip

Here's the scene. The car file can be found at the given url. Row 1: shader used in bump channel. Row 2: shader used in colour channel. Col 1: veloute Col 2: formula Col 3: brick Colour channel for the brick case didn't seem to do a thing. Odd. Anyhoo. The veloute in bump channel worked as I expected. The formula case doesn't look at all like the color channel even though the formula is exactly the same. The brick has the shown problem tha the creases are light instead of being dark and the surfaces are dark instead of light. I also tried changing the brick to be in combination with a mixer operator. Meaning. Bump: Mixer - Source 1: 100 - Source 2: 0 - Blender: brick It gave a different result but the result was still incorrect, or at least not what I was hoping for.

I thought I'd throw some light on the subject to get a better look at things. I assumed you had Veloute 2 installed.

Message edited on: 04/15/2005 23:17

In Amapi 7 I found these points on the ends of your arch. I tried to fix it so that only quads were used. But then the UV mapping was made worse by by doing that and I don't know enough about Carrara to wrap the right kind of UV info around the arch for the Brick bump function to orientate correctly without pulling facets apart like what's happening in the previous image.

This information might help: I know that some of Carrara's shaders have a nice bump implementation (like the Cellular shader), but others use a default implementation that depend a lot on the scale of the shader (like the brick one). When I did Veloute, I made specific developments for the bump, so they usually give better result than the Carrara one's. What you could try if you want to use the Carrara brick shader in the bump channel, it's to use it after the Veloute Filter shader: it should improve the bump. Julien

You notice that on row one col 3 the bump on the upper surface of the arch is as you would expect and only on the inner surface is it reversed. Is this an anomaly due to normals being reversed on the inside of the arch or something similar?

Message edited on: 04/16/2005 07:15

Actually on another forum (3dxtract) someone was smart enough to set 1 to the vertical brick count. The black I/we are seeing is the groove of the first brick layer seam (grout). I feel dumb. :P Mystery solved in my opinion. However with 1 for the vertical you get a seam that runs the length of the object. Not what I want so it would appear brick isn't an option for me to use in this case. However the formula case for bump mapping still doesn't look proper. Maybe that is something Eovia could look at. Thanks all!

I would just keep the arches you did with the Veloute 2 plugin. They came out the best. I'm curious though what more can be done to get brick bumps to work better on the inner edges and outer sides?

I made this with the Tiles bump pattern. But I must delete two points from the mesh. I dont have Velout so you can try use it with my file: [arch2.zip](http://www.grutadaonca.com.br/noviski/arch2.zip)

Message edited on: 04/17/2005 10:42

Another way to skin a cat.

Thanks all. I think I've settled on veloute with some tweeking with brightness, contrast and bump height and I'm getting close enough to what I am looking for.