The bump map
This one has quite a few layers, and it uses a rough copy of the "sediment lines" Gradient Ramp. You could just instance it, but I didn't. Why? It will all be clear soon... Here's an image of the bump map maptree. I've left out the water part of the bump, I'll cover that later. Below is a render with both the diffuse and the bump map enabled.
- Well then. Again we start with a Compostite map, again to separate the water from the rest, which means two slots. Next, put a Mix map in the first slot, name it "canyon wall and mud bump" since that's precisely what we will be mixing there.
Before I continue, I need to talk a little about the vertex colour mask. If you need to adjust the transition from one map to another, you can put two vertex colour maps on top of each other. In this case, I would put an additional Mix map in the first slot with the Vertex Colour map as mix amount control, and the mud bump map in the first slot, leaving the second slot empty. This will make the transition from mud bump to canyon bump a little more abrupt, and let the mud bump area be a little smaller. This will mostly be noticeable in the transition area, so it's pretty subtle. Here are two images where you can compare the difference. With the added vertex colour map, without the second vertex colour map. So, a second Vertex Colour Map softens the transition, but I won't be using it in this version of the shader.
That's the one of the ways you can control the Vertex Colour map without having to repaint it (since repainting it might destroy other maps and masks that you've setup). The best thing would be if you had different vertex colour channels, as you have different mapping channels. That would be awesome. But we don't, so we have to resort to trickery. Oh well. Back to creating the bump maps.
* There's a way to use multiple vertex colour channels in max 5 using these two plugins: Copymap and UVWRGB. Thanks to Reality3d for pointing it out. 3dsmax 6 comes with an improved vertex paint modifier and 99 channels which should make this a breeze.
- Put an Output map in the first slot, name it "mud bump strength control". I put this Output map there to have better control of just how bumpy the mud will be. Since there will be many layers of bump maps, having additional control over how much the different layers affects the end result is very useful.
As you can see, we once again have a Mix map on your hands. So lets fill that sucker up. This is where the copying and instancing starts, and where you can start wiring parameters.
- Copy the Mud Diffuse map to the first mix slot. Here's where you could use an instance instead of copying since they will need to use the same settings except the colour slots. If you do an instance, and keep the colour maps, the mud bump won't look as cracked as it should, since the Noise maps will interfere. There are a few ways around this:
- Going back to the Diffuse level, you could separate the Noise maps we put in the Cellular with a mix map. We wouldn't get as much variation (Cellular maps come with a Variation setting for the colour) nor control over the colour of the mud. The benefit would be that we get a "raw" Cellular map that we can instance all over the place, the downside is that we get an even deeper Diffuse map.
- Second way would be to wire the important parameters, such as Size, Spread etc. With wiring you can have bi-directional control, so if you change the size in the diffuse version, the bump version will change too. Very handy. The downside is that it's a bit of a mess to try and link the right parameters together, many levels to wade through to get to the right place. Also, wiring might cause max to be a little unstable.
- Third way is just manually copy values and never change them again (as if that would ever happen).
- Going back to the Diffuse level, you could separate the Noise maps we put in the Cellular with a mix map. We wouldn't get as much variation (Cellular maps come with a Variation setting for the colour) nor control over the colour of the mud. The benefit would be that we get a "raw" Cellular map that we can instance all over the place, the downside is that we get an even deeper Diffuse map.
- Going back up a level, we put an Output map in the second slot of the Mix map, name it "mud bump strength control". This one, together with the mix amount map, will preserve the cracks, but give the flat areas a soft bump. The Output map is there to give us finer control over how much it will affect the end result.
- In the Output map, put an Electric map, named "mud bump softener".
- Back up one level and instance the Cellular in mix slot 1, the one I have so fittingly named "same settings as colour mud" to the mix ammount slot. Thus the dark areas, the cracks, will be sharp and the flat areas, the "chunks", will recieve a slight bump. Since it's supposed to look as if water has been running over the mud, having a strong bump is not what we're after, but having perfectly flat surfaces is also a big no-no. So just slip that Electric map in there with an easy to control instance and you get a soft bump which fades into the cracks nicely.
Lets move on to the canyon wall bump.
© Peter Åsberg 2003