Render use 1 Bucket because of displace enabled...

[3LP]

Hi there,

I'm having some trouble using displace on a project that I'm working on for the moment.
I have a simple sphere using displace and when i'm setting the displace as enable (VrayDisplacementMod) my render takes ages because it use only 1cpu.
But my memory isn't struggling at all... Only 29% of my ram is used.

I have tried to increase the dynamic and the static memory limit even to 64.000Mo and it still use one cpu and not all of my ram.
I had read that the VrayDisplacement was based on displacement per bucket to preserve memory if i'm not mistaken, but why does it use only 1 cpu ? I have 8 buckets on my screen.

Could someone please help me, i'm struggling to render my final images. In the mean time i'm disabeling the displace, but I have to get them for the final output.

Thanks!

Stan

[TheLooopCGI]

The problem was already reported earlier and Vlado said they will try to work on it... I'm not sure about the exact cause but it has something to do with a certain part of the displacement calculation being only single-threaded. It's not a big trouble if the displacement is not very heavy, in which case it takes a very little time so you don't notice anything, but in heavy displacement scenes it is a problem.

I don't know how are your scene setup but in our case we tried to minimize the use of VRayDisplacementMod and tried to substitute it with standard 3dsmax displacement modifier where possible. Also try to avoid 3D displacement where possible. With 2D displacement you will also get this problem but only during irridiance map and lightcache calculation.
Another important thing to be aware of is the fact that the displacement is calculated even if it's not in the camera view. So try to limit the extension of the displacement and hide objects not in direct camera view or turn off displacement for those objects. Also you can first render a whole picture without displacement and then render certain regions and enable displacement only for objects in those regions.
What also helps is reducing the displacement quality.

It's quite annoying but at the moment there is no other way I fear

[vlado]

Also, you need to make sure that the "Dynamic memory limit" option is set high enough.

Best regards,
Vlado