displacment won't render

[gilicom]

Hi , we are in the middle of a very urgent tv commercial production and i can't render 2 frames out of the 84 that are in this scene.(all the other 82 rendered with no problem)
the problematic frames are 77,78 , if someone have time to look at the scene and manage to render those frames, please tell me what was the problem.
the scene is very simple , just a cylinder and a box with displacment on.
the scene - (right click and save it)
http://www.3dvision.co.il/wip/disp.zip
thanks for all of you who will try to solve it.
Gili

[Candelero]

Hi gilicom,

I am currently downloading the scene and will be looking into it...
If someone else is also trying to help, please report if you guys
manage to solve the problems. Thankx.

EDIT #1
Getting a message for a missing *.mov file...
Is it of big importance ?



Best Regards,
nikki Candelero

[gilicom]

thank you very much for the super fast reply
btw I've tried all 3 aa methoods and dinamic and static memory.

[Candelero]

@ Gili,

Dude, can You please show how a normal frame has to look like...
That would give me the most precious info...
Thanx !

EDIT #1
Render-time for a frame ?

Best Regards,
nikki Candelero

[gilicom]

Nikki
here is frame #76

You can render all the frames exept 77 and 78 .
all the other frames render in 2-9 min per frame.

[Candelero]

Here is Frame# 77



Really strange it is taking so long time... so far 50 min rendering..and still going
I have done nothing BUT hit Render...

At least I will save You the TGA file, so that You can insert it in your animation, if that would help your Rush... !

Probably would be looking for the problem afterwards...

EDIT #1:
I also noticed there is an Alpha chanel involved it that with a shadow, as far as I can see from the Frame Buffer, is that right ?

Best Regards,
nikki Candelero

[gilicom]

nikki
I've got the same thing going on with frame #77.
You can stop it and just try to solve the problem cause i still need to work on that animation.

I also noticed there is an Alpha chanel involved it that with a shadow, as far as I can see from the Frame Buffer, is that right

yes that is right i have a surface with matte shadow material , the final render should be tga with alpha.
ctualy frame #77 and frame # 78 are still trying to render for more then 5 hours so i gues they won't render.
I've also sent the files to vlado.

[Candelero]

Ok, frame stopped.
Looking for the problem into it

BTW, on what PC are You getting those 2-9 min rendertimes... ?


Best Regards,
nikki Candelero

[gilicom]

p4 3.ghz 1g ram slaves

[Morbid Angel]

gilicom, you problem is adaptive subdivision aa. I set my aa to qmc sampler and this frame is rendering fine. I also suggest reducing the number of displacement subdivisions all though that shouldnt matter much. Another thing to be aware of, is how you build your object for displacement, in other words you cant just divide and object in one direction and not keep any polys in another, this is making it very hard for displacement to work efficiently. By doing correct model the displacement amount can be reduced and thus speeding up rendering a lot.
Try this scene here and let me know if it worked well. I was able to render this frame in under 1 min.
http://www3.telus.net/public/vinnik8...ig01_fixed.rar

[gilicom]

thanks a lot mordib
it does render fine.
as soon as you set 128 to max subdiv it render no matter what aa you'r using.

[Morbid Angel]

yep...you see, the denser the mesh is the lesser subdivs you need. If you can achieve good result with lover subdvis then why not?.. I had cases where I had to use 2-4 subdivs and it worked just fine, and render times were barable.

[gilicom]

great help
thanks

[Candelero]

The MAIN biggest problem is the Cylinder itself... I increased the
height segments from 1 to 64, which actually divided the model into
small squared-type poly-model. (that's what Morbid Angel also reckoned).

Rendering the Frames #77 #78 took 1min each, without changing
absolutely anything on the render setup... AA is still Adaptive.

Have always on mind that 3D displacement mode needs an initial subdivided
model to work best with it. Having a low poly-count on the surface or having
extremely streched polies, like the cylinder with 1 height segment, is causing
the problem with the displacement, as V-Ray is trying to subdivide those
single polies and to produce small details like Grass.

And at last - Good work, Morbid Angel !!!


Best Regards,
nikki Candelero