i spawned several trees and rocks with the help of a scatter and a point wrangle (to set prefab instance and rotation) node. In unity some trees (small rotation of x- and z-axis, full rotation on y-axis) are rotated like rocks (random rotation of all axis).
I compared the rotation data in unity and houdini and it is different. What can cause this behaviour?
I did some more tests and it looks like there is something wrong with the conversion logic in the engine:
1. Scatter some points, add “unity_instance” and “instance_prefix” to some of them. Result is having e.g. trees without instance prefix. -> Seems wrong
2. Scatter some points, add “unity_instance” to all of them (some with invalid prefab name “remove”). Result is having trees, rocks and empty gameobjects. -> Seems ok
3. Scatter some points, add “unity_instance” to all of them (some with invalid prefab name “remove”) but now remove all points with unity_instance==“remove”. Result is having trees and rocks only. –> Seems ok
But in all cases i still got wrongly rotated trees. I even found a tree which should be a rock (assuming ids match: 3470 in this case):
Does the rotation bug show up only when combining trees and rocks in the same scatter? Do you get correct rotation for the trees if you only have trees?
How are you setting the tree and rocks values to your scatter points in your HDA network? Is it through 2 scatter nodes, or a single scatter with groups? Can you post a screenshot of it?
Can you provide a simple HDA that produces the problem so I can debug it here?
Would be great if you can submit this via our bug system so we can track it. Thanks.
seelan Need some more information to debug this issue.
Does the rotation bug show up only when combining trees and rocks in the same scatter? Do you get correct rotation for the trees if you only have trees?
How are you setting the tree and rocks values to your scatter points in your HDA network? Is it through 2 scatter nodes, or a single scatter with groups? Can you post a screenshot of it?
Can you provide a simple HDA that produces the problem so I can debug it here?
Would be great if you can submit this via our bug system so we can track it. Thanks.
I just put together a HDA with the three use cases from my second post. But case three refused to work, it removed the terrain somehow. But this showed me something interesting… without a terrain the rotation is correct!
I attached the asset with a sample network to test. If you toggle the blast nodes you see that the rotation changes with/without terrain.
