Questions about SpeedTree

Hello everyone,
i have some questions regarding the SpeedTree implementation. Current issues aside, there are a few things not very clear to me and i was hoping to find some answers here.

1. When you generate different meshes/variations of a single tree it's using the same textures as the previous one in the modeller. Does this impact performance when, instead of using the same model, i use different variations of the model ? I noticed that the modeller creates new textures and materials for that new variant even if identical, so i was wondering if i can actually gain some performance when just using variants of the same tree.

2. How do you officially recommend to implement SpeedTree Grass/Bushes. Should it be added as GameObject, like regular Trees or is there a different method ? Does it have a performance impact when placing it as GameObjects ?

3. When adding trees as TerrainTrees is there any limit ? What's a good maximum ?

Thanks!

 

Hi!
thanks for the detailed answers! Will help me a lot making the correct decisions for the terrain.

 

2. So it would be nice if we have usable alternative for using speedtree grass/bushes. Now it's simply not usable with terrains without custom solution.

3. I hope that limit of 65k trees applies to one terrain. So if we use more terrains we can bypass this limit..

Thanks
Peter

 

I've noticed a huge difference in performance between normal Unity Trees and SpeedTree Trees. In my scene I have close to the 65k tree limit on my terrain. I consistently can run my scene between 90-100+ fps (depending on where I look) when using normal Unity trees. However when I use the sample SpeedTree trees this drops down to about 25-35 fps. Has anyone noticed poor performance like this?

SpeedTree certainly looks great, but performance has to be there or there is no point. For now I assume this is just a development bug.

Edit: And to clarify, I'm mainly talking about the billboarded trees! In my example above I am not close enough to any trees to get them to shift into the lower lod levels.

 

Sounds like you are not using Version b22 or higher yet... They improved the performance in that build a lot, give it a try!

 

So there will be no improvements for terrain to use SpeedTree? We need to go with some custom solution to place speedtrees that will work with LOD?

Cause now when we placing the trees with terrain brush - LOD of speedtree is not working (and bunch of other terrain tree related parameters) (we on RC1)

 

You're right. I downloaded b22 and re-setup my scene. Granted there is a small improvement, now I get about 40 fps, but still isn't really acceptable compared to normal Unity Trees (now 130 fps solid).

 

OK, with beta22 there seems to be a HUGE Improvement with near SpeedTree trees (lod0-lod1), but rendering large numbers of billboards is still pretty much an fps killer.

 

You right - LOD is working - my terrain was too small to see LOD kicking in - I had to lower LOD BIAS in quality settings to saw difference.