Water
Now that we've completed the bump and diffuse maps, it's time to create the water portion of the diffuse map. Some of you might wonder why I'm putting the water in the same material as the rest instead of using a plane or something similar. The reason for this is that the canyon mesh in itself is smooth. If you wanted to have water between the cracks of the mud, yuo'd have to model the cracks by using a displacement map (or by hand if you feel like going insane) This one uses 2 bitmaps to mask the water, and it will be very scene specific. First of all, lets look at what we need for the water to work. Click the images for larger versions.
- We will need one bitmap for where the water flows. The main stream, small ringlets of water joining or branching off from the main stream etc. On my model, that looks like this:
We will also need a mask for the area where water has spread in between the cracks in the mud material. It will basically be the same map as the water mask, but a blurred and expanded version. On the left is the actual mudmask, on the right it has been layered on top of the water mask:
The small white area that we get with these two maps is where the water between the cracks will appear.
- If we add the vertex colour map to the equation, you will see how it all fits together. On the left, just the vertex colour map, on the right, all three elements together:
Here you can see how you have the mud as a wide dark grey area, then you have the little white band where the water has gathered in the cracks, and in the middle the actual water.
These are the only maps you need to make the water composite work. The order in which you create the maps is entirely up to you, although I can offer some tips. Start out by drawing a small stream with vertex colours on your model. It doesn't have to be very detailed, just a gnereal purpose stream. Export this using Texporter and bring it into Photoshop or other paint program to paint a detailed water mask. That way, you get a rough sketch you can paint on top of. When you're done with the water mask, show the texture in the viewport and paint the mud layer on top of it with vertex colours. Since you can display both textures and vertex colours in the viewport, it makes painting the mud a breeze. No guessing where the water will be etc.
Next we will put these maps to use. I've tried to name the materials so it's easy to follow what each will do. Let's rock.
© Peter Åsberg 2003