When building shader networks in the hypershade window it is common to drag-and-drop one node onto some attribute of another. When you do this maya attempts to guess the type of connection you are making. If you drag a texture or a material onto a color attribute then maya will automatically connect either the .outColor or the .outValue, depending on the node type. There are other default connections for other types of attributes but if maya can't figure out what to do it opens the connection editor and leaves it for you to make the connection manually.
There is one notable case that seems to confuse people - mia_material_x and mia_material_x_passes. For example say you want to layer mia_material_x over another shader using mib_color_mix or mix8layers. If you drag-and-drop the mia_material_x onto one of the color inputs instead of connecting as you might expect, up pops the connection editor. If you've done this before then you probably know that you simply need to connect mia_material_x.result, but wouldn't it be great if maya was able to do that automatically, and skip the connection editor?
If you said "yes, that would be great" then you'll like the next bit. Back around the turn of the century, the thoughtful folks at alias provided a mel script called connectNodeToAttrOverride.mel which states
// This procedure is provided as a hook for customers to allow
// you to redefine the behaviour of drag and drop.
Well that's what I've done. Three lines of code was all it took! Now dragging mia_material_x and mia_material_x_passes works just like the other materials.
You can download my modified connectNodeToAttrOverride.mel from my downloads page.
A few months back I wrote about using puppet's p_shader_replacer to override maya's fur shading with the p_HairTK shader. I discovered a strange anomaly that I thought would be worth a mention. But for the rest of this post to make sense you need to know how the p_shader_replacer works. If you don't, have a look here.
So here's the thing: The name of the object that holds the geometry shader and the name of the furFeedback node actually matter. Specifically, the name of the object that holds the geometry shader needs to come before the name of the furFeedback node from an alphabetical ordering point of view. And in this case capital letters come before lowercase.
So this works: pCube1 , polySurface1_FurFeedback - because "pC" comes before "po"
but this does not: pCube1 , PolySurface1_FurFeedback - because "pC" comes after "Po"
and this works: ApCube1 , PolySurface1_FurFeedback - since "A" comes before "P"
Easy once you know, but if you don't then depending on your naming some of your fur will just ignore the p_HairTK.
I'm currently using shaders_p v.3.3 beta 11 for Maya 2010 (win64) and find that p_HairTK is very stable, often quicker to render than maya fur and has better shading attributes. An especially interesting, and welcome benefit is that it fixes the NaN (black pixels) problem that seems to haunt maya fur.
Several years ago I wrote a mel script called djRivet.mel that makes it easy to constrain things to deforming surfaces using follicles. Matt Oldfield, one of the TD’s at Disney Interactive, suggested that I update it to include support for multiple uv sets. It was pretty cool to hear that someone other than me finds this script useful, and being able to specify different uv sets for the textures and the follicles makes perfect sense.
You can download the update here.