XSINYC Tutorial::::Texture Blending

This is my peach! There are many like it, but this one is mine!

Sadly, however, my peach is somewhat flawed. The problem: you can't really unwrap most objects without edges, lines or uglies. One solution is texture blending. I like to use texture blending because it's fast, easy and effective.

(They do tend to clutter the render tree a bit, but you can always Render Map the end result and bake the tree into a single image.)

So! To begin, let's examine my scene. You can see below the way I've unwrapped my peach.

The ugly area is being created by the top and bottom rows of my unwrap. 10 polys across the top and bottom share vertices: they should connect in a more radial fashion, but they don't.

The first step: Create a second Texture Projection. The way you generate this projection is important, in order to avoid later confusion. You'll need to select the peach,

Get --> Property --> Texture Projection --> Create New Projection

This is important because you need to be able to name the projection, which you cannot do if the Projection is created in the Render Tree Image PPG. (Incidentally, it's always more efficient in the long run to create all of your texture projections this way.)

In this case, it's ok to ignore that it defaults to PlanarXY, as I'm going to do a local reassign.

Tag the problem polys (below) and then re-project them using the tex editor projection tools, until you get something like what I have below. The problem exists on both sides of the peach, which is why there are two crescents in the editor. Next, position the Projections so that they cover, and will therefore project, the desired area of the Texture Map. Since peaches are somewhat asymmetrical, I made sure to choose very different areas of the texture.

Another important step, collapse all of the other polys into a single point. You can do that quickly by selecting the rest of the polys and pressing "CTRL + _" and then "CTRL + |"

Ok, so now I have two separate texture projections that I can cycle through using the UVs button in the Texture Editor. The next step is to Stamp the UV mesh. In the Texture Editor, select

Edit --> Stamp UV Mesh
or Shift + S

I usually stamp to a "blank.pic" with the dimensions of my primary texture. Load your stamp in Photoshop and paint a gradient in the UV areas:

The gradient will control the blend between my two different texture projections. Right now, if I swap between my different texture projections, and textures, it looks something like this:

Original Texture &
original Texture Projection
(Peach_Whole)
Original Texture &
second Texture Projection (Peach_Blend)
Gradient Texture &
second Texture Projection (Peach_Blend)

OK! Almost there! Now, all we have to do is hook it all up in the Render Tree!

Breakdown: Peach Radial is my original texture. I'm piping that texture through two different texture projections (Peach_Bland and Peach_Whole) and into a mixer (literally, Mix mode). In that Mixer, I'm driving the interaction between the two projections through the gradient I created (Peach_Blend_Weight).

Now, if we draw a Render Region around the original problem area we can see that's it's fixed.

Scott Stewart
XSI|NYC Admin
www.scott3d.com