Announcement

Collapse
No announcement yet.

SpeedTree performance

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    SpeedTree performance

    I am making a very big outside level with a pretty big amount of trees, I have made and compiled my own SpeedTree. I set up wind speed to 0 (i dont need them moving). So any suggestions or tutorial on how would use large amount of trees on the level, with pretty good performance?
    I am trying to make something looking like this:
    http://www.youtube.com/watch?v=BAqbn...eature=related

    #2
    Well, try to keep the trees as simple as you can get. Also don't even try using dynamic shadows. I don't think there's much you can do other than that.

    Comment


      #3
      We're doing some big tree counts and have come up with a few strategies for the speed trees:

      1) Get your LOD working! Getting the LOD to work properly with speed trees is essential! If you cen get all the morphing and fading to billboards to work right, you can really populate your scene with an absurd number of trees.

      2) If you need to do dynamic light, consider using more fronds rather than leaf cards since the leaf cards' shaows change dramatically based on the angle of the camera in relation to the dominant light.

      3) Of course, model the tree in a very low poly manner. Trees in the UDK tend to look much 'fuller' than they do int he speed tree editor, so you will likely need fewer leaf cards/fronds to fill out your trees.

      4) Deco layers on terrains are great! you can paint on your trees/vegetation and can easily edit the trees en masse as well as add or replace trees as needed.

      Hope that helps a bit!

      PS> When you set the wind speed to 0, did the tree stop moving?

      Comment


        #4
        Thanks for tips, one more question, is it possible to do grass in speedtree?

        Comment


          #5
          I think so, but it would seem to be overkill, unless you wanted it to sway along with the trees. A simple mesh based deco layer/foliage factory would probably and likely be less of a performance hit.

          Comment


            #6
            Thanks for help. The big drawback on speedtree in UDK it doesn't allow to save results as static meshes
            Yeah, I guess even for trees, since i dont need wind speed I could use static mesh. Its just how can I create one in 3ds Max without such tool as speedtree. I would be huge amount of work i think, or there is some plugins for max that could do that?

            Comment


              #7
              Usually 'grass' meshes just consist of a few intersecting double sided planes, which is easy enough for anyone to put together.

              Comment


                #8
                Unless I did something wrong, my experiances with LODs and speed trees are really bad. I made a very simple looking tree with around 200 triangles on the highest level, and around 80 at lowest. Oddly enough I got less frame rate with the LODs working rather then the trees staying at their highest LODs. The same can be said with the terrain. My guess is that the more the engine has to calculate changes, the worse the performance seems to get. This seems to make sence because this engine isnt really well known for dynamics. When you have a giant forest of speed trees that are all calculating distance and LODs every frame, it makes sence for the engine to take a dump.

                I'm doing something very similar by the way. I have a huge map with lots of speed trees, and other foliage. My advice so far is forget LODs, but unless someone can tell me that I'm not doing it right and prove to me that lots of trees + LODs = good frame rate, then I'd also appreciate it.

                I think there is a threshold when it comes to LODs with speed trees. My theory is that the more trees with LODs you have the more needs to be calculated for changing LOD levels. But if you have less trees then there doesnt need to be a large number of calculations and that is when LODs would actually increase performance. So because there are a lot of trees, it may actually be better to take the stress away from LOD calculations for hundreds of trees and keep them at their highest LODs.

                There is one thing you could try, and that is make static trees with wind being simulated in the materials of the leaves.

                Comment


                  #9
                  I'll tell you right now that LOD with speed trees work great and is a huge performance benefit, at least in the Jan Build (Feb borked the speedtrees LOD system). Also with the terrain, if you spend the time to learn the objects and get it working "right" there's huge performance benefits over the static versions. You really do have to spend a lot of time tweaking however and it's really an art rather than a science.

                  I have several huge scenes with thousands of static meshes, hundreds of speed trees and miles of terrain all running without a hitch, when I turn off LOD, my frame rate crawls. I did, however spend days and days getting everything to work just right.

                  Oh, another tip for huge outdoor levels:
                  http://udn.epicgames.com/Three/Visib...ance%20Volumes

                  Comment


                    #10
                    Would you be willing to explain exactly how you setup your speed trees with LODs?

                    Comment


                      #11
                      it's at the build time when you pick the option to compile speedtree actor create some billboard then and then open your speedtree properties in the editor and that's it

                      http://kankeine.blogspot.com/2009/11/outdoor-02.html

                      Comment


                        #12
                        i am not sure if he meant UDK setup or SpeedTree application, but if u have just Tree selected in SpeedTree Modeler in option on the left there is section Level of Detail.

                        Comment


                          #13
                          Originally posted by InhexSTER View Post
                          i am not sure if he meant UDK setup or SpeedTree application, but if u have just Tree selected in SpeedTree Modeler in option on the left there is section Level of Detail.
                          you did not understand. To use billboard you need to create them within speedtree. So if you want to create Lod you need to create your billboard and it's done at building time inside speedtree application.

                          Comment


                            #14
                            Well no thats not what i ment. I made LODs already, but the few things I noticed with using them is that my frame rate actually goes down, and I also notice two trees on top of one another where I get the nasty flickering of the textures. I dunno why but everytime I enable LODs on the speed trees I get two trees in one speed tree. It is almost as if there are multiple LOD levels displaying at once.

                            Comment

                            Working...
                            X