V-Ray 6. Hotfix VFB Lag and freeze while using IPR and moving in Viewport

Hello,

When I using the IPR, the computer freezes and then the Viewport has a performance drop as its so difficult to move stuff or work Realtime in IPR.
I tried updating to the new hotfix but the issue hasn’t been addressed. I have reverted back to V-ray 5.2.3. this is so buttery smooth compared to V-Ray 6.0

Looking forward to address the issues. I am looking forward to upgrade to V-Ray 6 for production.

//Best Regards,
Mohit Sanchaniya

Hi is this happening to all scenes even a new simple one? It will be best if you could send us a scene that reproduces the issue. You can do this here or through our support contact form.

Hello Vladimir,

Its happening in even with the simplest scene, as well notice a scene loading before light cache taking a extra time compared to the V-Ray 5.3.
I ain’t sure about sending the scene but during the IPR the freeze and defreeze of computer happens. May be I can show it to you guys on live interaction through call or something. Even some of my friends using V-Ray 6 have experience this lag or sudden freeze.

Hi you can write a message to the support contact form. Add a link to this thread and I will answer you there so we can arrange a remote session. Just one last thing - are you using 3ds max standard camera in your scenes (physical camera)?

Hi, I wanted to add that we experience the same overall freezing of the Framebuffer and even Windows since we updated to Vray6.
Most of the times it’s just the Framebuffer not refreshing until the render is fully finished, and sometimes Windows completely freezes. That happens on both Intel and AMD CPUs, on Windows 10.

Hi @joaquim_montserrat1 is this happening in IPR or production rendering? Is it happening in all scenes even a new simple scene?

Hi, it’s happening on production rendering with CPU. It also happens on network rendering. And it also happens with all types of computers, on all scenes. We’re using 3dsmax 2023

Hi the thread is for IPR, please open a new thread in the 3ds max issues forum. Production rendering is meant to take all available resources of your PC. It is expected to have big impact on other processes especially if you are running out of memory.

Hi, I think I found the solution, executing this in MaxScript fixes the slowdown for us :
renderers.current.system_lowThreadPriority = 2

system_lowThreadPriority was = 0 in some of my scenes. Not sure why some had the setting = 2 and some at 0. This setting was exposed in Vray 3 and 4, but not anymore?

I’m having the same issues. It’s very hard to use IPR and work in viewport and the material editor with production scenes. There’s a lag. Maybe V-Ray should not use all threads of the CPU when IPR is working so that the interface and viewport have enough CPU resources?

I have similar problems with IPR. I’m testing V-RayScatter, V-RayENvironment Fog and V-RaySky. IPR is _really_ slow, sluggish, makes 3ds Max unresponsive. I have feeling that prevoius verision was better in that regard

I have the same issues when rendering with Progressive IPR. It used to be less problematic but with V-Ray V6 it’s worse than ever. Running the script ‘renderers.current.system_lowThreadPriority = 2’ does not help much.

I’ve spent a year periodically searching for a solution to my serious lag in Max when renering a progressive IPR. This solution seems to have solved it for me. I use a program with which I can assign which processes a particular program uses. I let Max use all but 4 of my 32 processes. When setting it up for Max I just excluded Max from the first two processes and the last two processes for no particualr reason so that other programs could utilize them. I didn’t realize that there was a priority to the processes that was that important. I reassigned Max back to the first two and and excluded it from others in the middle. Like magic, I now have a pleasant experience using Max while IPR is running. I’m thrilled to have found this. Thank you @3d-laboratory .

So if others are having the issue and even if you don’t use a program to manage processes, try making sure that Max has exclusive use of the first process and see if it solves the issue for you.​

Hi @RobH22 ​ . Very interesting. By “processes” I assume you mean “threads”, right? How can I make Max have exclusive use of the first threads?

Yeah i have very much the same sounding issue.

I have tried setting up max scene by scene to low priority in windows, as well as disabling 2-4 threads.
It indeed worked even thought its quite not handy and annoying to have to do, but it showed improvement.

However i started to have a lot more crashes which of course is not helpful, so to me no real solution found as of yet.