Rendering large amount of trees for animation
 

Hello, it's been a while since i was here.

Now, I have this scene where customer is asking me to create lots and lots of trees. I made them using paint effects and converted them to polys (like 8k polys per tree),and if i render scene that doesn't show distant tree, it's all ok. But if i point camera so that it show distant trees too, maya just stops rendering. The problem is, that i'd like to render nice, raytraced shadows. So, one thing that comes to my mind, is something i know games have.
So, is it possible, when you render short animation with this scene, to tell renderer to render only tree that are close to camera? If not, what other option is to render it?
I'd use paint effects, but they don't have raytraced shadows.
So, any suggestion?

---edited---
Also, i don't know much about render layers, but would this help?

Render layers or maybe swap out some of that stuff for planes with images on them. Your poly count can go through the roof with converted paint FX, I'm not surprised Mental Ray choked on it lol.

yep.., like GecT said :)

Ok tnx.
You mean like planes that automatically rotates towards camera? Hm, for some of that i suppose it could work, any other idea?

A lot of games have the trunk of the tree and a few large branches made from geometry while the leaves and smaller branches are made from a bunch of rotated planes (so they give the illusion of being 3D geometry) with textures. From a very far away distance, they look convincing...

many film use plates too.., its usually only 'hero' objects that have geometry.., you wouldnt believe how much 2D you are looking at in every movie.., ie, could easily be the inside of the death star thing in starwars.., being the landing bay. the ken burns effects has been appended to a very high level.

this question has come up so often it would be worth one of the mods running a ut on it.., if you look at mikes free alpha tut you might get some ideas.

no pint creating geometry for an object in the distance.., its a time waster.., production houses everywhere would think anyone who did that crazy.., though for a hobby at home.., why not?? (time and stress??)

Well, what I mean by "very far away distance" is a distance that is far away but where non-geometry trees are easily noticable. That is why the large solid parts use geometry and the leaves don't.

Well one problem is, that when i say distant objects (trees), it's only distant for some time. since camera is going around this city, at some point, trees are far away, but later, camera will get close to them. I'm not sure how exactly this works, but i just though i wouldn't render all those trees from distance until camera gets near them, and only them would it show full detailed tree. Something like LOD levels in games.

How ironic, I've already been working on something very similar, but geared more toward features than games.
So, think larger, and more photoreal.

Were working on it, have no fear:)

Btw, how would i make so that paint effects uses polygon plane for branches instead of models?

In games, they are mainly textures with alphas mapped to planes.

So if you can imagine the tree as geometry, (or a plane also in some cases), then 2 or more planes with branch textures applied on top in a cross-pattern.

Like so:
http://www.datenform.de/blog/uploade...000-703606.jpg


Then when rendered, and/or seen from a distance, they look pretty convincing in a game situation:
http://img.photobucket.com/albums/v5...H/WIP/tree.jpg

ok tnx.
So, i suppose there isn't a way to tell maya to render tree only when it's close enough to camera?

Also, if i make instance objects, i suppose that could reduce memory useage. I was makeing test and watching memory usage and i saw that while regular 3 trees used 274 mb memory, while instanced only took 264mb. which is 10 mbs less and that's for only 3 trees. But is there any way to cut down memory usage even more? Even if it takes a bit longer to render?

Just a thought, maybe swap out out some of the geometry for those image planes with the level of detail feature. /shrug

i remember seeing a tutorial that showed how you can have maya automatically swap out models depending on how close the camera is to the model. in the tutorial they used a lamppost - so when the camera was close to the model, it would be a highpoly version, when it was a certain distance away, it would be a mid poly model and when it was far away it would be a low poly model.

i'm pretty sure it was a free digital tutors lesson that i got off of itunes - so it might be worth checking out their podcasts.

hope that helps. :)

tnx a lot arran, i'll check it right away!

--edited--
ok found the video, and i like it a lot. Now if i could only add distance from where the last lod can be seen, so that from that distance on, it wouldn't be seen at all. That would help a lot.

Also, i tryed rendering from command prompt. I think it uses a bit less memory this way. Can somebody tell me how much memory do i save this way?