Population not resting on object

[sboerner]

Can anyone think offhand why a population would hover above the surface of an object instead of resting on it?

The population anchor is set to "Sit on object" and conforms perfectly to the surface, but hovers about a half-meter above it. It's easily fixed by adjusting the Y translation of the populated object, but I'd like to know why it's happening.

[WAS]

Few things I can think of

• The populated objects center is higher than you think
• There is some sort of displacement applied to the object, changing it's computed geometry
• The object is scaled and for some reason TG is using the base object dimensions

Not sure really. I tried to reproduce this with a few objects and grasses but they all sat on the surface.

[sboerner]

Thanks. Those are all good possibilities but none check out. The object is scaled, but the same offset occurs when I reset the scale to 100 percent.

Strange. If I stumble across the cause I'll let you know.

[Dune]

Strange indeed. And the pop object itself is exactly at 0/0/0? Did you try another object as population to see if it's that particular pop object or the object it sits on?
Occasionally, I had the pop on object change again to sit on terrain, by itself, for an obscure reason (probably a mistake I made).

[sboerner]

It's happening with two different populations. Haven't looked into it any more than that, since adjusting the Y translation of the pop objects seems to fix it.

Probably should set it up in a new scene, with just the main object and populations, to really test it.

[sboerner]

While we're on this subject I thought I'd mention that it seems populations on objects are applied on a Y projection instead of UVs or something like that. So if you have an overhang the population isn't applied to the "shadow" underneath. Hadn't realized that before.

[WAS]

So if you have an overhang the population isn't applied to the "shadow" underneath. Hadn't realized that before.

Yeah this was an issue I was having with it, and was unfortunate. I wanted to do something with floating land masses like Avatar but couldn't populate the depressions I specifically made for plants >.<

[Dune]

Yes, that's right. If you want to populate overhangs/undersides, you have to use a (second) pop with X or Z rotated 180º.