Emitting points from polygons


Here’s an ICE tree that emits points from the polygons on the emitter, using their PolygonPosition attributes.

Emit_points_from_polygons

As an exercise, I went to the trouble of using the PolygonNormal as the direction vector. That was slightly complicated, because I couldn’t use the EmitLocation attribute to get at the PolygonNormal. I had to use Get Closest Location with the new PointPosition instead. That’s because when you use positions instead of locations with Add Point (which is inside Emit from Position), then the EmitLocation attribute is “meaningless”, to quote the documentation.

There’s no such thing as PolygonLocation, so I had to use the PolygonPosition attribute.

Note also that I filtered out some polygons, so that I emitted points only from the faces of the soccer ball.

Emit_points_from_polygons_ex

PolygonPosition is read-only


Too bad, I had such big plans for this 🙂
PolygonPosition_red

So, now that I’m at a dead end, let’s go over the different ways to figure out why a node is red…

Point to the node and wait for the tooltip to show the first error:
PolygonPosition_tooltip

Right-click the node and click Show Messages.
(Log port type details can be useful sometimes, but not in this particular case.)
ShowMessages

Read the documentation.
PolygonPosition_doc