Problem with High Resoloution Renders in 3ds Max using VRay 3.60.04 (after using 'Large Image' settings)

[ryan_wright]

Hiya

I am having problems rendering using VRay 3.60.04 in 3ds Max at a high resolution (9933x7016). I have used the published standards documented in https://docs.chaosgroup.com/display/...y+Large+Images. However, this does not seem to work and the render still crashes when 'building embree static accelerator' with the 'dyn mem limit' is set to 0 under the Settings/ System tab in the render settings window. Can anyone please help?

[Art48]

Do you have displacement in the scene and maybe forgot to turn down edgelength? Have you monitored your RAM if it crashes because of overload?

[ryan_wright]

I do but it is at the default of 4 px and I currently have 64gb RAM. The render works perfectly for test renders of 1754x1240 but anything above that it crashes.

[Art48]

4px seems like way too small for a render that size. So since you didn't answer the question: Are you sure it's not a RAM issue? Have you monitored the RAM usage while the scene is loading up to be rendered and starting to render? Try disabling displacement and see if it works. I strongly suspect RAM overflow.

edit: And sorry, I meant "Did you forget to turn UP edgelength"

edit2: Usually rendering an image that size shouldnt be a problem or even a use case of the special workflow with writing to vrimg directly without memory framebuffer. We render big images like this regularly and we rarely have to go down that route.

[ryan_wright]

Hiya, I did observe the RAM usage and it was through the roof and when compared to switching 'displacement off.' There is a considerable difference in RAM usage and it appears to be working now I have switched it off, thank you so much!

Are there any correct procedures for using displacement or is it mainly used for more close up scenes?

Apologises for my lack of knowledge as I am quite new to this software. You really are a lifesaver! I have a deadline for tomorrow morning which I may actually meet!

[Art48]

Hey - glad it worked out for you. As for displacement there are several ways to manage RAM with it.

When using 3D displacement, the higher resolution your output size, the larger the edgelength of the displacements needs to be to keep RAM in check. 3D displacement actually creates a mesh at rendertime and the edgelength in pixels determines the density. For lower resolution images with lower pixel dimensions you kan keep a low edgelength. For larger images you need to increase it because otherwise you will get a very very dense mesh, blowing your RAM.
I think that VRay already manages the geometry that is displaced well, but you can do stuff like cutting off the geometry outside of camera frustrum.

Another way, depending on the setup of your displacement map and working independantly from resolution is using 2D displacement. This only works with non-procedural textures and a single UVW channel though so it is more limited but at the same time can save a ton of RAM.

With your setup I would first try to double, triple or quadruple your edgedistance until the RAM doesn't overflow instead of disabling displacement altogether.

edit: It actually doesn't matter if you're rendering a close-up or not. The principles stay the same.

[ryan_wright]

Ahh, ok. I will test this out but after my deadline is over with thanks again for your help!