NatXotic Posted August 10, 2003 Share Posted August 10, 2003 Hi there, anybody can give me some advice in how to generate a tree quickly? I used the L-System and it works pretty fine so far. I put a leaf geometry into it and it comes up. My problem though is that it takes sooo long. I tried a couple of approaches. One was with particles, the other is with bgeo geometry. I thought if i create a twig with a couple of leaves, save the geometry and then insert the twig into my big tree. But it runs forever. I want a nice tree with lots of leaves in it. i know that takes it's time, but i thought it's a bit faster than an hour+ (killed the process after an hour of waiting). The particle approach i tried because i thought it would be needed if i want to make a little wind blow through the leafes. So anybody there that can tell me if it's normal to take so long, or is there a lot easier approach and i am again shooting myself into the knee? Thx Quote Link to comment Share on other sites More sharing options...
michael Posted August 10, 2003 Share Posted August 10, 2003 you could try using instancing for the leaves...so that they will only be used at render time... Quote Link to comment Share on other sites More sharing options...
NatXotic Posted August 10, 2003 Author Share Posted August 10, 2003 can you tell me more about this instancing? I know about particle instancing, but how could i instance a geometry in SOP's while using the L-System? Does the visibility flag help? I'm gonna try that one. And i'll post my tree.hip file as soon as i can go back to houdini Edited: The visibility node seems to work. One more question. Does it matter if i use one L-System as k-Input for another instead of making it as one entire L-System? Or is it better to use a pre generated geometry file instead of a L-System. Leaf ------------------------- | | Leaf - L-System |--- Geometry-File L-System1 or ------------------------- | | L-System2 L-System2 Quote Link to comment Share on other sites More sharing options...
michael Posted August 10, 2003 Share Posted August 10, 2003 check out http://www.sidefx.com/community/learn/effe...ticle_tips4.pdf the last couple of pages give a walkthrough of doing it.. damn...these legacy materials are a real goldmine yeah, post your hip, I'd be interested in seeing it Quote Link to comment Share on other sites More sharing options...
NatXotic Posted August 10, 2003 Author Share Posted August 10, 2003 There ya go. You can go into the Tree SOP and then export the leaf geometry as leaf.bgeo by clicking on the shader SOP. That should give you then the missing bgeo. I will now give the trunk some roots. Thx for the help. Took me like 5 hours But learned something, what is good. edit: if u know how to tweak it to get a better performance, i would be still very thankful. Tree.rar Quote Link to comment Share on other sites More sharing options...
michael Posted August 10, 2003 Share Posted August 10, 2003 how close do you need to get to the tree...or to the leaves? I rebuilt your leaf - yours was huge!...I couldn't even load the final L-System to see it on the tree...LOL anyway...when you open the scene just go to the shader and save it out as leaf02.bgeo, then load it back in and you'll see the difference in how heavy the scene is....note that I spent about 5 minutes building that leaf...so if you spent an hour or so more on it you could get a pretty good leaf I think....then add to that a nice texture an you'd be rocking... HTH Tree_new.zip Quote Link to comment Share on other sites More sharing options...
FrankFirsching Posted August 10, 2003 Share Posted August 10, 2003 I rebuild your scene to use instancing for the twigs. You also don't need to save out a .bgeo-file anymore. The drawback is, that you don't get a feedback in the viewport anymore. The difficult was to to instance the twigs, but to orient them in the same way the l-system did this. Unfortunately the l-system-SOP disorganizes custom per point normals. Therefore you have to feed a local coordinate-system instead of a single point into the k-leave of the l-system. This can then be used again to recompute the normal and the up-vector. It can also be utilized to compute the scale of a specific instance and store this value in the pscale-attribute, which is normally used for particles. Tree_InstancedTwigs.zip Quote Link to comment Share on other sites More sharing options...
NatXotic Posted August 10, 2003 Author Share Posted August 10, 2003 Arctor, the leaf didn't take me long. Maybe a minte or so. i am pretty alright with polymodelling. Still like my leafes better, no offense. Wooww - Frank. Dang if i look at your file i notice that i still have a long way to travel. Some of the nodes are just miracles to me. I kinda get what you'd been doing. Just using those nodes would have never come to my mind. You want credits for that? I will take your version, because this is just so smooth. THX Quote Link to comment Share on other sites More sharing options...
michael Posted August 10, 2003 Share Posted August 10, 2003 I agree my leaf isn't much...I just wanted to point out that you could get something pretty good for about 1% of the polycount...depending on your needs... yeah, I'd take Frank's...<smartypants> Quote Link to comment Share on other sites More sharing options...
FrankFirsching Posted August 10, 2003 Share Posted August 10, 2003 No problem. I just watched coincidently the geometry-instancing video-tut from SideFX this week. Quote Link to comment Share on other sites More sharing options...
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