Hey cheers!!
I just experimented, instancing trees also works when they have leaves (which are instances themselves, so this could have been a problem)
Too little ram for renders though ;(
Using the tree itself for an instance for its leaves, lead to a crash


Maximus: The ICE tree for the instance is like this: I used a primitive->pointcloud->grid, randomized the points in XZ axis a bit, and tweaked a little terrain elevation with the move point tool.
Then attached an "instance shape" node with the tree point cloud, a "set particle size" and a "set particle rotation", last two fed with random values.

It's important to go into the "particle display" property of the grid pointcloud, and set it to something else than "automatic", otherwise you'll have OpenGL performance problems.

I've also experimenting some tree instancing with leaves, and they work just fine, aside from the heavy openGL which I had to set display as BBox, and tremendous amount of RAM mental ray needs to render it (12gb was not enough for 50 instances!). I'm sure Arnold can handle some million instances very easy though.

About using the tree istself for instance on the leaves, probably led to an infinite loop, that's why it crashed! =)

Yes after rethinking this, I'd suggest to rather steer clear of instances of instances. Mental ray doesn't really handle this well.

It should keep the hierarchy, instead it "unpacks" all those instances, probably in order to avoid double SRT lookups. I had 6000 trees with 4000 leaves each. Mental ray creates 24 million instances now. This is bad, imagine having 50.000 trees with 10.000 leaves each. If you have 1 kb overhead for each instance (not a too unrealistic number) you'd be at 500 GB RAM usage

I think I'll try the Pointcloud deinstance script next

Ok I modified (&uploaded) Jules' pointcloud deinstance script so that it works with trees (In his version every point has to have a shape, for trees only leaves have a shape)
Some foresty renders might be following xD

I assume the version on your website is the upload you're referring to.
If so, it probably would be wise to denote it as a/the modified script
(as the file name "pointcloud_deInstance_03rrmod.py" implies)
not the original...

done

nice, I'll try the script asap.
Also this would solve the problem with colors/materials of instances of instances.
Maybe for mray the less problematic workflow would be to generate mesh from the pointcloud using Andy's saveRenderMesh (for branches), and deInstancing leaves using your mod of Jules' script (since saveRenderMesh cannot handle instances, at least that I know). It'll need an extra step in the workflow, but can be more render friendly and controllable (read: lattices, weightmaps, uv editing, etc)

let me know if you have any success.

I have done a few poly instancing tests. These are 45.000 instances of this simple tree (1-polygon leaves, no branches, only trunk remodeled)


firefox does some weird color correction to jpgs so I uploaded this as a gif

*rendertime: 3 hous
*ram usage: 1 GB
*randomized Y rotation, particle size, particle Y scale

Hi ray thanks for tests,

btw Its not weird colour correction but embeed in jpg color profile of your monitor. Same goes with alot of screengrabs from diffrents users posted here. I see yellow xsi interface instead of gray. Check photoshop options when saving for web.

btw2 I think I will send you some of my scripts Ray...I had one pc deinstance script with str animation to keyframes...lost in when doing hdd cleanup.

rray - nice tests! You should really have a look at arnold for those renders, its much much better at memory management on big scenes.