I was comparing render speeds by doing tests on tiled exr vs. tiffs. First I was rather disappointed. There was a speed gain, but only from really far away, then moving the camera closer the rendertime of the tiled EXR started to creep up and passing the tiff shaders rendertime. going in on a closeup of the object finally caused maya to crash.
I re opened the file and turned off displacement in renderglobals, and suddenly the performance I was looking for was there.
can anyone try to reproduce this?
my setup is a vray material with 4 different tiff textures in displace, bump, reflection color and diffuse. A copy of that shader only with exr’s instead of tiffs.
Thanks
Martin
EDIT: I took this snapshot of my netcard load after doing two renderings. It clearly shows that tiled exr’s makes total sense. Nice feature!
I was under the impression that you don’t want to tile displacement due to the nature of the multi-resolution and the way it would dynamically load that you might get undesired results in displacement.
@ Mr furious yes, you might be right here. But I still think it should not behave like this. But it might be unimportant if it not desireble to use tiled EXR’s for it.
Have you tried increasing the dynamic memory limit? You can also try using a separate texture cache using the VRAY_TEXTURE_CACHE=N environment variable where N is the texture cache size in megabytes. By default V-Ray uses a common memory pool for dynamic geometry and tiled OpenEXR files, which may be a problem if the memory limit is too low.
Thanks Vlado, I’ll test it. I have noticed several places that the answer “upping the dynamic memory limit” pops up as it might be set a little low as default. What would you suggest it to be for a lets say a 12gb system? Or is there a % scale I can use? The reason I ask is that I’m thinking about creating a script that sets things up the way that we like to work, so I don’t have to do that manually every time.
Sorry, the -m option is when using exrmaketiled.exe from the openexr webpage. If you use img2tiledexr.exe it should do it by default. ( I tested them both, and I only got it to work with img2tiledexr.exe by some reason. I guess I confused the two. )
Btw. Does anyone know a program that can actually view the different tiles? Right now the only thing I can check is to see if the load time of the bitmaps shrinks when using them…
Thanks Vlado!
I also have some bad news regarding the tiled exr’s. In my test It reads in faster, but doubbles the rendertime some how. It might be because of the higher bit depth, 8bit tif’s vs 16 bit exr’s. So I think for this time around I will have to go with the tiffs after all… If I get the time, I will try to dig deeper into what is going on..
Sorry Vlado, due to a 26 page NDA contract I can’t send anything out..
But I can see that my computer is running out of RAM with the full res textures. I think that the exr’s are consuming a little more ram than the tiffs due to the bitdepth perhaps. rendering with 1/2 scale textures my computer pulls through without reaching my 12 GB limit. The rendertime difference between tif and EXR is almost nothing then.
If I get the time, I will try to dig deeper into what is going on..