Hi…
We are rendering an animation with a boat on sea with Backburner. We use Vray displacement in .ILF file on top of a noise map as sea. But halfway in to the animation the displacement has started to “flick”. It seems like it use the wrong displacement file in some frames.
Question: Does the ILF file have to lay on all of the machines in the renderfarm? or does it take them from the machine where the backburning was started from? (I think I restarted that machine at some time)
… 
try lowering your edge length in your displacement settings.
It would be helpful if you can post some images or send them to vray@chaosgroup.com so that we can take a look.
Best regards,
Vlado
here is a mov file of the prob!
http://rapidshare.com/files/13767504/flick.mov.html
Percy: we are using 2d displ., we used the settings for the ocean in this thread, http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=17959
the render nodes will look at the same path as the saved max file , meaning if your ifl is on d:/maps all of the servers will look at their local d:/maps
so you can do the folowing :
1. copy the ifl and maps to all the servers , make sure they have the same path.
2. map one of the hd on your network as map network drive, keep all of your textures over there and in the future you won’t have those problems.
yep, we have one map’ed drive, also tried to copy all locally.. but thats not the problem.. the problem is that some frames is not rendered correctly..
mabe some of the servers find the same map , but older version on their local drive.
rename all their local maps pathes so all the servers will render only from the network drive.
Thanks for the reply, but we have tried it, and it doesn’t seem to be the issue.. 
Maybe you can try to convert the animation into another format (e.g. separate image file for each frame).
Best regards,
Vlado
we have tga files files of the displacement, which we used, but it was converted to ilf at some point..
Did it work with the .tga files?
Best regards,
Vlado
sorry vlado, the files is not tga but jpg’s… (I’m the other guy on the project)
When we render the sea on one computer there is no problem, so it must be a network/backburner thingy. We really should have a solution on this because this sea is by faaar the best to use… We used DM before and there was a lot of trouble with it (memory, tilling and scaling)
Chris
Well, maybe you can do some tests to figure out where is the issue (I am not sure of that myself):
(*) render the sea without displacement, but with the displacement map as Diffuse map, just to see if it really is a mapping problem
(*) if it is a mapping problem, render just the noise texture and then just the bitmap textures to figure out which one of them is actually flickering;
Depending on what you get from these tests, the solution could be different.
Best regards,
Vlado
This might be impracticable but might get you moving.
Try using the displacement modifier instead of render time displacement via VRAY. Take your displacement maps and stuff them into the modifier.
A plane sub-divided via Meshsmooth at render time to the point just were is is not crashing works for projects I have done and you will know if it’s Max or Vray causing the issue as a result.
Cheers
Mike k
Hi again…
When studying the frames closer I’m not sure it is the disp map thats flicking, but perhaps the lighting or something. We are using Irrmap as first bounce and lightmap as second bounce in render settings (I know… it should be QMCin first bounce). Vray sun for lighting and a VraySky in the environment slot of the sea material.
There is no problem for the first 5-600 frames but then it starts and gradualy increasing to every 5-20 frames (in a different sequence it started after ca 250 fames) It seems to be random, not a particular computer in the renderfarm
There is no problem when rendering all the frames on a single computer. Lenght on total animation is about 5-6000 frames.
Here is two following frames in the animation. The structure in the waves is pretty much the same, but the way the light reflects on the wave is quite different. In the “flick” frame the sea gets a bit darker and its less internal reflections on the surface.
Any tips?
Vray Displacement on sea:
Sea Material:
RenderSettings:
Sun:
[/img]
I havent read through all of the post. However I will say that this is not the displacement indeed. It looks like one or, some machines on the farm are not loading a texture or an object or something. Since the surface of the water stays consistent throughout, and rather something else offscreen pops on and off.
I suggest to make a step back. Render a test animation with a vrayMtl grey override, to see if it is the geometry/displacement first. If its not, then turn off the displacement and render the animation with the water shader and all objects. See if something is poping on and off.
Hope that helps.
Hi… Have done some tests. In the first column you see two frames rendered by the renderfarm. Frame 4186 represent the “look” of the sea and frame 4187 is the frame that “flicks” and is again followed by a frame that looks similar to 4186. The frame that flicks on the renderfarm (4187) is actually the “correct” result as shown on my workstation (see “My workstation”).
* When this frames is rendered on my workstation they both look correct.
* Rendered with a grey vray material the displacement is the same so it is definitively not the displacement that is the problem.
* There are no objects in the scene that flicks on/off and thereby affects the reflections/light on the sea as “Morbid Angel” suggested (see “overview”)
Possible problems?:
* I get a “Scene bounding box is too large, possible raycast errors” (the sea surface is quite large. It the seasurface plane too big? (1000 meters)
* That the scene is in millimetre?
It seems like QMC in the first bounce fix the problem…
holdon…yes ofcourse! since you are using displaced animation, irradience map wont cut it. Though I dont know if the artifacting is what the irmap should have done, but usually if objects are deforming/moving frame to fram irmap is outof the question.
But why dont we have this problem when we render on one machine then? Does different machines calculate different? :? Just curious…