View Full Version : Can you plug multiple maps into Bump?

06 June 2006, 12:44 AM
I'm using multiple maps on a character mixed with mix nodes and alphas.

For example

Arm color map
Chest color map
Head color map

They get mixed with a mix 8 node then piped to the color layer.

How would I do this for bump maps?

The bump channel is vector...

I'd need a:

Arm bump map
Chest bump map
Head bump map

and mix with 8 node, then pipe them into a bump channel.

The problem is if i do a conversion, the object looks self illuminated. The bumps not working if i pipe the mix node into the bump generator node or bump channel...

Any ideas how to do this?

06 June 2006, 04:20 AM
I think i figured it out. I'll write a tutorial on this stuff to keep me from forgetting it might just help others...

But so far... what i'm doing is using texture layers...

I'm piping in the mix node with all of the maps mixed (with bump map turned on in the image nodes), into a layer that effects just the bump. That seems to add some color to the diffuse and ambient as well. It seems if you put the layer on hide/reveal/multiply it wont effect diffuse...

not sure why. hehe

But ti seems to work, although my eyes may deceive me.

06 June 2006, 08:26 AM
in theory threre's a couple of ways to do this:

mix everything in RGB space then push through a bump map generator node

or add stuff together in vector space. See for a vid tutorial on how to do this.

The former is the simpler but there are caveats. Most notably, all the nodes you use have to pass bump map information through and many of them don't. Most annoyingly the mix nodes don't and that kind of banjaxes the whole thing.

alternatively, get Ben's Zbump node which will take RGB input from anything. The quality is way higher than the bump generator node too.

06 June 2006, 11:35 PM
yeah Zbump is great.

Makes you wonder what they're doing over there at soft and MI ;)

sigh.. i'm using 2 mix 8 nodes. 1 plugs into the base of the other mix 8 node. I ues this for all of the diffuse color maps and its causing my render to hang.


06 June 2006, 03:30 AM
Another thing that you can do is use the Mix 8Vectors shader here: Basically, all you do is use a bumpmap generator for each of your bump maps, pick the proper texture projection, bump factor, etc. and then enable each input in the Mix 8Vector. I recently used this in conjunction with the Texture Layer Editor with good success. Depending on what you are trying to accomplish, you can create render maps of your object(s) and flatten everything down to a single texture and single bump map.

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06 June 2006, 03:30 AM
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