Stencilling
by Matvei Mihaljov


I know that this tutorial is very monotonic, in "do this and to that" kind of way ;). Just ignore it. This tutorial is aimed at people who are familiar with editing Blender's materials and textures. It will explain you how to use a Blender feature called stencilling.

If you turn the stencil option on for a texture, that texture will be used to give "borders" for other textures to operate within. Stencilling can be used for smooth blending from one texture to another. This feature even works with bump maps. The only texture Blender can't stencil is stucci material.

Some parts of this tutorial might be inaccurate, or even false. This is simply due to the fact that I haven't spent much time with this feature myself. Therefore readers' comments are very much appreciated. Send your feedback to matveim@hotmail.com

Below is a picture of what you will get after finishing this tutorial.

We'll do this tutorial on a plane because the changes on the material are best visible on a plane object. Press Ctrl+X to start with a new scene. Delete the small plane. Then switch to fronview and add a new plane. Still in editmode and all vertices selected, scale the plane 2 times. When you're done leave editmode.

In MaterialButtons screen, add a new material. Make the color of the material blue.

In TextureButtons screen, add a new texture. Make it a marble texture. Push the car button to give it an automatic name.

Go back to the MaterialButtons. Make the color of the texture red. Now you should see a nice, red and blue marble surface.

Now to the stencilling part. Select the second texture layer and open up TextureButtons screen. Add a new material of type blend. Push the FlipXY button, we want our material to be divided horizontally. Click on the autoname button and you're done with this texture. Now get back to the MaterialButtons. Let's get rid of the ugly pink color and make the color of this texture yellow. And now, the part you've all being waiting for... Push that magic little stencil button above texture color sliders!

Next you'll see what that button really does. Select the 3rd texture layer and open up TextureButtons. Add a new clouds texture. Autoname it. Then back to the MaterialButtons (again). Change the texture's color to .5 of green and 0 of red and blue. There you have it, a stencilled material! Not so hard, was it? But the fun doesn't stop here, next week we'll do stencilled and nonstencilled BumpMaps. Same bat-time. Same bat-channel. Okay, that was a lousy one, just read the next step.

Add a lamp and render the scene. You'll notice that the change is too soft. We'll sharpen it by selecting the second layer, and in the TextureButtons change the type of blend from lin to ease. We'll also increase the contrast to 2.

Select the 4th layer and add there a new clouds texture. Adjust the NoiseDepht to 0 and the contrast to 2. Name this texture CloudBump. In MaterialButtons turn off the Col mapping and turn on the Nor. Adjust the nor value to 5.

All we have to do now is add a nonstencilled bumpmap. We'll do this by selecting the 5th layer and adding a stucci texture there. Autoname it. Back to MB screen, turn the col off, nor on and adjust the nor value to 2. Adjust SizeX, SizeY and SizeZ to 5.0. Now were done! For some reason the stucci texture screws up the lighting making the lower part darker. Just add another light source and you'll be fine.