Rotating vectors around the global X axis

Another Rotate Vector example. This time, I rotate the points of a mesh around the global X axis. In short, the point positions are treated as vectors, and then rotated about the specified axis. Of course, this requires some conversion between coord systems, which is always fun🙂

The bottom part of the tree is just for visualization.


Get Closest Location and position coordinate systems

When you’re using Get Closest Locations, positions are local. That is, they are relative to the local coordinate system of the object that “owns” the ICE tree. The input Position is in local coordinates, so in most cases, (0, 0, 0) will do fine. And if you use the output locations to get positions, those positions will be in the local coordinate system of the ICE tree owner.

Hat tip: Gray, who has posted this several (many?) times over the years.

Integer division in ICE

Dividing an integer N by itself doesn’t always give you 1.
I think it’s a problem in the Divide by Scalar node (the division is probably returning a scalar like 0.99999999, and then that is truncated to zero when it is converted to an integer).

A workaround is to do all your division with scalars, and then use modulo to determine whether you Round or Floor the result. Here’s an example compound by Guillaume Laforge:


Missing ICE nodes in the preset manager

I’ve noticed this a handful of times, where a node like Get Data isn’t found in the preset manager. Clicking the Update button always fixes it for me.
The last time this happened, instead of clicking Update, I started Process Monitor and did a few more searches in the preset manager. In my case, Softimage searching only the compounds, not the presets in %XSI_HOME%\Data\DSPresets\ICENodes. That’s why nodes like Get Data weren’t found.

Clicking Update forced Softimage to search both the compounds and presets.

Context matters: Using weightmaps with point clouds

A weightmap is per-point, but it’s per-point on the emitting geometry, not the point cloud. So you can’t just do a plain “get weights” if you want to use the weightmap to control particle values like Velocity or Speed.

Instead, you use get a location, like the particle emit location, and then get the weightmap value at that location. Then you’ll have a particle per-point context to work with.
When you get the weight at a location, you get an interpolated weight value.