Leaf Collision

I am a new speedtree user and having issues with understanding how the post process collision for leaves works. I understand that you have kill ratio setting w/ tolerance in the leaf generator, and low medium high settings in the tree window to turn on the different intensities of collision culling, but when I turn on collision, at any quality level all my leaves disappear. I have tried adjusting tolerance from 0-1 in the leaf generator to no effect, and setting to either quick or accurate also does nothing. How do I get speedtree to just cull leaves that intersect and not the entire node? Any advice would be appreciated

Hi @kenlyl,

Welcome to SpeedTree!

Could you share your tree with us? That will be the quickest way for us to pinpoint the problem. Go to “File”->“Package for support” and either post the zip here, or email us at support@speedtree.com.

If the file is too big, just drop it in Google Drive and send us the link.

Mira,

I may have found a way to get a better result that I think is the correct workflow? I turned use spherical on, and then adjusted the spherical threshold to .2 for the leaf generator and that seems to be working o.k. I presume the collision for the leaf card does not take the opacity map into account so while it looks like the leaves are not colliding in the viewport, the polys that are masked by the Opacity map are, and that is what is causing them to disappear???

0_HeroTree03_20-12-2024.zip (586.8 KB)
Here is the current tree

Hi @kenlyl,

Thanks for sharing your file!

I totally missed something in front of my face last week :smile:

So, “Cluster plane overlapping” is generally meant to be used in Cluster files. When it’s enabled, any leaves that share the same camera space (not 3D space) will be tested for removal. So you’ll want to make sure that’s off.

To your last question, that’s right. The collision test is based on the cutout, not the opacity map. So transparent parts colliding will still count as a collision.

As for your method, scaling the spherical threshold down like you mentioned can help the look because it will make the sphere colliders smaller and thus reduce the number of collisions (the spheres are initially based on the leaf’s size). For collision without spherical testing, you can adjust the Pivot threshold.

All in all, if you found settings that work for your needs, that’s great! :slightly_smiling_face: