displacement and big output images

[thablanch]

My standard render size is 3412 x 2700
I do have a really wrinkled seat, wich I do displacement on, works really fine in previews (800x600) but when going to prod size, it just : crashes or get stuck on lightcache for 2 days (really 2 days, killed the rendering after 36h of rendering and I was at the 7th blue bar in the process display)

So, as I can not use displacement, I went normal map, wich does not seems to work with vray material

So, what is the size limit for lightcache to kick in?
Normal map, why does it works in standard mat but not vray mat.

Thanks for any suggestions

[Clifton Santiago]

I had a similar problem when strip rendering through backburner.

I was rendering a 3000x2250px image with a 4 hr render time on the farm.

When I added a displacement map on the grass, the 800x600 draft render only took 1.5 hours. When I rendered with displacement at 3000x2250 it took 14 hours.

My lightning fast new machine which was rendering 11.25 px strips @ 10 min. each, got stuck on one strip for 8 hours!

[Candelero]

@ thablanch

Is that 2D or 3D displacement ?

Best regards,
nikki Candelero

[Clifton Santiago]

2d... I can never get 3d to look good for grass

[TRGraphics]

I'm curious if the newer builds for DR fix that problem. I have the same exact problem with.03 version.

Tony

[Morbid Angel]

for 3d displacement you need to tesselate the surfaces before applying 3d displ.
I may also suggest trying qmc for sec bounce. Could work.

[vlado]

Increase the Edge length for 3d displacement. Since this is pixel-based, increasing the image resolution will make V-Ray to produce a lot more triangles, which will eat your RAM.

Best regards,
Vlado

[thablanch]

Canderelo: this is 3d disp

The displacment map is imported from zBrush, as the lower rez .obj

(Max object, exported to z-brush at first, baut as zBrush changes slightly the geometry, I had to re-import to apply displacement correctly)

Morbid Angel: As it is to match the output zbrush file, can not really tresellate. (but I can try deleting the lower level in zBrusk and re-import a higher density mesh, thanks for the idea )

Qmc does not really work, well, not in my tests

Thanks guys

[Clifton Santiago]

Morbid: Thanks for the tip. I'll try smaller tessellation.

thablanch: Sorry to hijack your thread. I guess my problem is different than your question.

[Candelero]

@ thablanch

If You are using a zBrush Displacement map - best way is to use the VRayBmpFilter...
Refer to :
http://www.spot3d.com/vray/help/VRay...ter_params.htm

And also as Morbid said, it is definately better if the surface is tesselated somehow, as 3D Displacements needs some basic subdivided surfaces to work faster.

Best regards,
nikki Candelero