About static meshes with no collision

[Bret Hart]

What can I do about tree meshes with no collision? Such as the gnarled trees found in UT3 UN_Trees package? Some of them have no collision but I want to use them.

[Sharpfish]

Put a blocking volume around them (A cylinder or two), as before. The actual collision would be too costly and a DOP box may not fit too well so a thin blocking volume on the trunk and a wider one up top (if it needs it) may be ok. Oh and I think you can turn on collision per mesh in it's properties if you want to try that and test the performance impact... I can't tell you because I don't have UT3 yet.

[DGUnreal]

Use Blocking Volumes, you don't want to use per-poly collision at all if possible. The other option is to create a custom collision for the model in the editor using CSG and "Save Brush as Collision" but you can't do this easily for stock cooked content.

[-=¤willhaven¤=-]

Some of those meshes had a "_BC" version added near the end of development. BC stands for Better Collision and was used for one instance in one map so it wouldn't cause any issues with other levels. I know some of the static mesh trees had two versions for that reason.

[Entil'Zha]

On the topic of Static Meshes and Blocking Volumes.
Why do almost all static meshes have a blocking volume around them.
(like the stock maps, at least the maps I looked at)

Some maps are loaded with blocking volumes.

Is it because the "calculations" are easier on blocking volumes? And if so should collision be disabled in the properties of the static mesh ?

What when how to use them ?