Is it possible to have two different bumps within the same shader?  Let me give you an example.  Lets say I want to make a really good brick shader.  Once I get the colors down now I need to have a very fine bump for the grout and a larger bump for the bricks.   I have tried mixing the bump channel with the Mixer operator, but that didn't work.  I also tried using layers, but again there is something I'm not understanding because that didn't work for me either. Here is my attempt with the mixer in the bump channel.  Can anyone tell if its possible to do this?  If so, how?!

Thanks
Mike

Hi Mike, I think you were getting too complicated with your shader tree. Try this structure. The color and bump must share the same mixer function so everything lines up correctly. Another option is to create two shaders and blend them as a multi-channel mixer with the brick function. Doing it like this actually makes for a more simple shader structure. They both get the job done however. Mark

Mark, thanks for the reply.  I'm still missing something.  I setup my shader like yours and I don't get any bump at all.  Maybe i'm just tired or something...

Here is the scene file.

Arrghh!!  okay Ichanged the file extension to .txt but it's really a .car file.

I use the Veloute Tile plugin.  It allows you to choose different color and bump for the brick and the grout.  Then I turn on displacement for the entire shader.

I had thought of Veloute also but I could not imagine it would be any better than with Enhance C in this instance. We really do have great options with the plugins available for Carrara.

Mike, your bumps are probably too similar. For the bricks, only mix the lighter values. For the Grout, mix just the lower/darker values. There needs to be enough difference between the two so that one receeds and one advances. 50 percent gray is flat as far as Carrara's thinking. Veloute is an excellent choice too as mentioned by Shonner. But since you set up with Enhance C, so did I. Enhance C is soooo versatile and so deep in features though - it's got to be my favorite plug for texturing.

Mike I just played with your file. Because of the way that it is mapped onto the Cube primative, you'll need to use the 1-1000 value slider instead of the color or the 1-100 slider. This kind of weirdness can be prevented by either UV mapping the object or by using Flat mapping and designataing a face on the cube. The stretching of the object plays havoc with bump and texuring.

Thanks for the help, Mark.

So if I add a UV map I will have less problems with this?  Interesting... If I don't go into the UV editor what does Cararra use to map the shader?

Also I discovered something strange while going through this excercise.  When I change the shape of the cube by shortening one side the bump all but goes away.  But if I make that side larger than the original cube the bump gets deeper.  I believe this is why I wasn't getting any results with my original straight forward mixer shader.  I already had the cube shortened to a wall shape.  Now, this doesn't seem quite right to me.  What do you think, is this the way it's supposed to work?

I used Anything Goos to age my tiles.