stupid vray primary visibility alpha tip

when using primary visibilty and alphas start going black, try doing ->

render globals, vray globals , materials max transparency levels and set it to something higher than the default of 50. maybe 500...
comes in useful for hiding fur and you want a seperate tech pass with just a shadow. omg.

credit to Tony Bosworth Cosgrove for this handy hint

particle kill field, maya sorta

stolen from somewhere...

Maya doesn’t have any such thing as a ‘killField’, so were are going to hack one using a uniform field node. Select the particles, then create the uniform field. Rename the uniform to killField. Set these settings:

Magnitude = 0.001

Attenuation = 0.0

Direction = 0.0, -1.0, 0.0

Volume shape = cube

When you have the particle selected and you create a field in Maya, the field is automatically connected to the particles. Now that the uniform field is created,scale it up in the scene so it is underneath where the particles are falling as I’ve done here:

In the particle attibute editor, change the lifespan mode to lifespanPP.

Now that we understand that, lets create a particle expression to tell Maya what to do with this killField. Open the attribute editor for the particle system, right click on lifespanPP in the per particle (Array) attributes section and choose ‘Creation expression’. Now add this expression:

if (mag(inputForce[0]) >= 0.001)

{

lifespanPP = 0.0;

}

mel script to fix octane render bullshit messing up hypershade..

optionVar -remove "renderNodeTypeTreeInitializeUserProc";
optionVar -remove "renderNodeTreeInitializeUserProc";

yeti things

nice info here - http://the-art-of-rouhollah-toghyani-blog.16451.n7.nabble.com/

basically instead of flooding a mesh with guides, as I've been doing, place guides with a little more thought & use it to drive the length of the "grow" & play with the influence radius.. Using a texture for the initial "scatter" density still seems to work well, although clean edge transitions still look a little patchy. I think using some maps to drive the opacity of these areas might help. ie, start to fade hairs as they approach the edge?

Crux of the link is - Use layers of hair - set A is a sparse distribution with correct lengths and overall shape. set B adds density and is clumped to set a. set C adds further density & some flyaways.

motion vectors nuke/vray/maya

• render in 32 bit exr format
• nothing should be clamped

• in nuke, grade the blackpoint of the velocity pass to 0.5
• shuffle copy the R & G into your target's forward U&V
• use vector blur
• set to forward, tick on alpha
• probably have to clamp values on your beauty before applying the motion blur, otherwise fringing occurs...

pole vector moves joints

One problem that I remember having over and over (since I’ve never rigged frequently enough to ever learn the correct method) is that when applying an IK handle to a joint chain, and then applying a pole vector constraint to that IK handle, the joints can sometimes move subtly. It’s not always a big deal, but it can be a problem when you’re trying to have multiple matching skeletons for FK and IK control, and suddenly your rotations don’t line up anymore.

The fix, as it turns out, is really easy. Before you apply the pole vector constraint, you need to place your controller (whatever is going to drive the pole vector) exactly between the start of the IK chain, and the end effector, e.g., the shoulder and the wrist. This is quickly done by selecting the start and end joints, and then the controller, and creating a point constraint (do not maintain offset). Then delete the constraint. Next, use an aim constraint to point the controller directly at the middle joint (say, the elbow). Delete the constraint. Then you just need to move the controller along its pointing axis a little ways, to push it away from the bones. For example, if your aim vector for the constraint was +X, then push your controller a few units forward in its local X axis. Now you can create the pole vector and the joints shouldn’t snap at all

stolen from http://www.toadstorm.com/blog/?p=129

Zbrush displacement To Maya (arnold)

Zbrush to Maya (arnold) displacement map..

• sculpt your sculpts at higher levels, bla bla
• open up Multimap exporter in the zplugins menu
• set mid to 0
• select the subdiv level you want to bake down onto (typically 1)
• toggle 32bit and exr to ON
• set adaptive, smooth UV & 3 channels to off - http://www.cggallery.com/tutorials/displacement/
• I'm sure there are cases when you'll want to play with those last ones
• When connecting the displacement in Maya, you probably have to connect the R to the Displacement, instead of the default Alpha value. Go figure.

this works with Vray too! Remember to add appropriate renderer specific smoothing - catmullclark/vray subdivs etc.