Rendering time problem exponential each frame, ICE instance

[NNois]

hello, this is the second time it happens to me, in scene with ICE instanced objects.
My render time simply grow up by 2 each time a frame is rendered, caracterised by a "pause" between frames, the rendering phase itself isn't more long but it's this computation phase who cause the problem.
I solve it a little by stopping the batch render and restart it (with - skip on), there the rendering is normal... for the first rendered frames and so on...

My ICE tree is static and only generate particles at frame 0 (and instanced objects). I know it's a ICE problem or an XSI problem, but where ? maybe can i add an option for clearing something at each frame ?

this happens on XSI 7.01, 7.5 and 8 (on two completely different projects)

Maybe someone already had this problem ? and a solution ?

Thanks

[origin]

I have similiar issue. Don't know any solution.

A scene with several ICE trees with ~70,000 instances (non animated) each about 400 polys.
Rendertime grows each frame, memory also grows until computer runs out of memory (mentalray crashes, some db tag bullshit dialog pop ups)
For example first frame renders for 1 minute, frame no. 300 renders 3x slower. But If I cancel rendering and start rendering again (even without restarting xsi) it renders again normally, 1 minute per frame.

Rendering with rasterizer.

[NNois]

Arf, for me I'm try to understand why this instances computing phase grow up at each frames, it's a serious problem

[Mathaeus]

It seems to be known problem with using Mental Ray assemblies. All factory compounds under geometry instancing folder, have a ShapeInstanceTime attribute inside, which calls MR assemblies.
If you don't use animation from another frames than current one, you can try to use ICE tree like this:

http://www.matkovic.com/anto/temp/inst-classic.png

This will use 'classic' instances, it should render with same speed like particle instances before ICE times. It will still use animation from instances, but only from current frame.
It's important to use 'Instance Shape' node, and *do not* have 'ShapeInstanceTime' attribute anywhere in your compounds.

[NNois]

whoo ooo, this workaround works very well, and give me also a render speed gain right from the first frame !
Thanks

Noël

[origin]

Well I do use instanceshape because of that bug..

now I started to wonder...I plotted this cloud before rendering and afaik by default it saves some shapeinstance parameters like time... So maybe mr is using assemblies anyway

[NNois]

for me removing the shapeinstancetime port in the compound do the trick.
Piotrek, a small question, how do you plot a cloud ?

[origin]

animation-write geometry cache

unticking shape instance time didnt help, still leaks memory

[NNois]

Hello,
I come back to this tread because today i need setshapeinstance time plugged in....
Anyone had found a workaround to this bug and rendered animated instancied geometry without this very long render time ?

[Hirazi Blue]

Found this post on the mailing list, this may ( ) answer some of your questions, while it probably won't solve the problem, I'm afraid...

[NNois]

For the record, I think i've solved partialy the problem by controling manualy the number of MR "standin" by limiting fractional animation. In fact MR takes memory for each instance time, so if you use a random number for your instance there is a chance you are using a fraction of a frame, and this multiplied by all your instances! For me, by limiting instances frames rounded keeps a reasonable render time...
edit:
well after somes hours of rendering and some thousand of frames, my problem is always here but minimised, i give up and split frames groups of 10