Trees "popping" during animations

[kopar]

So, every few frames in my animation, all the trees seem to lose their transforms (rotation, scaling, etc). I am using Vray Proxies in Max 2009 with Vray 1.5 RC3a and backburner. It's Forest Pro 3.2.7b.

This has happened with several scenes and several proxies and is fairly predictable. It only seems to happen every 30-40 frames, sometimes more. It isn't tied to a single machine or any other single entity I can identify.

Has anybody had a similar problem before?

[iToo]

Do the trees reset to their default values of rotation and and scale, or are getting different random values ?
Does the problem happen in all trees of only with some of them ?
Did you have this problem in versions previous to 3.2.7b ?
Are you using area density falloff ? (because this bug fixed in 3.2.8b: "Fixed popping trees issue when using spline density falloff")

However, we have almost rewritten from scratch the scattering algorithm in 3.2.8b, is possible that this bug be already fixed. Although this version has its own issues (because the changes introduced), in the next days we will release 3.2.9b with many bugs fixed.

[kopar]

It happens to every forest system, some using the distribution map and area splines and some using explicit points. It would appear that they are being reset to no rotation and scaling. I can't say if we had the problem before as we had additional problems on old versions that would have superseded this issue. Otherwise, we're rendering tens of thousands of trees pretty effortlessly!

As you can see in the two bad frames, the trees are all very aligned and uniformly scaled, whereas in the good frame they are nicely randomized.

[BB1610]

Hi, i had similiar problem, and it was caused when using `horizontal mirroring` on custom objects was turned on. Disable it and try to render again.

[iToo]

Yes, we have recently fixed an issue related with random mirroring. We detected it in 3.2.8b, but possibly it was failing in previous versions as well.