Hi
I am trying to render using the VRay Render Mask set to Layer. The VFB updates perfectly during rendering but the file sequence that is saved are all empty 32bit PNG’s.
Any ideas?
If I select None for Render Mask it saves the rendered images fine but that is not what I need here.
I also clear the Vray FB before starting this process as I just want one layer rendered with scene reflections captured in the layer object materials.
Thanks
VRay Next GPU, Update 1.1, Max 2019
Just an update, the only way I can get the animation to save to files is using the “Vray Raw Image File” option to save. The normal “Render Output - Save File” does not save renders that use a Render Mask.
Stuck again.
The docs say I can set Vray to clear previous render (when animating with Render Mask) so that I do not get a kaleidoscope effect but where is it?, been through every single panel and just can not see that option under VRay CPU or GPU.
Scroll to bottom of the help page here: Chaos Docs
The docs say: "When rendering animation with Render Mask, the previous render can be cleared by going to the Render Setup window > Settings > System rollout and setting the Previous parameter to Clear"
Where is that setting? It is missing?
You would need to switch to advanced or expert mode for that to be exposed. It’s then top right in the system tab 
Cheers
Half way there as I can see that is now exposed when rendering engine is CPU.
What about GPU? This job is a Vray Next GPU render and uses the Render Mask. No System Tab, No option to clear previous.
Hello,
Thanks for the pointer - I managed to reproduce the issue with saving from the “Render Output”. Will log this bug in our system.
As for the option to clear the frame buffer - it is indeed not present in V-Ray GPU. We have this logged in the system but unfortunately it is not fixed yet.
Sorry for the troubles.
Best regards,
Yavor
I have given up and just done done this part using VRay CPU and will colour match it all in post.
So to recap this experience.
VRay GPU does not support saving animation files if you use the Render Mask
VRay GPU has no option to clear previous making it a useless option for animation
VRay CPU supports Render Mask and saving to files as you would expect
VRay CPU Render Mask set to Layers does not work, it still wants you to select objects.even if you have chosen next to it which layer to render.
VRay CPU can render a single masked image in 20 seconds on a 4770K vs Vray GPU which takes 2 minutes using 2 x 1080 Ti’s
On a simple test this seems to work - can you elaborate a bit more ?
Hi
I selected a Layer from the popup window after clicking the “Layers…” button but when I tried to render it showed a dialog that said “An object must be selected” and aborted. I double clicked the layer in the Layer Explorer to select those objects and then it worked but that is the same as “Selection” for Render Mask.
My layer did include a few objects that had the object properties “Renderable” deselected so not sure if that was a factor. I will re-test this on Monday to see if I can reproduce this one.
Thanks
Hi Yavor
Have these been fixed at all?
>> VRay GPU does not support saving animation files if you use the Render Mask
>> VRay GPU has no option to clear previous making it a useless option for animation
Thanks
The first one - not saving animations when using the Max output is fixed in the nightlies already. The other one is not.
Ok thanks for replying Yavor,
Is there a pre-render MaxScript command that I could use to set a global “Clear Previous” if it is just missing the UI element or is it more complex than that?
Thanks
Unfortunately there’s also a bug related to the clearing that prevents it for progressive rendering. I’ll have to test it with bucket actually - it might work.
Ok. Fingers crossed when you find a solution, good luck.
Hmm I found kind of a solution but it is not very user friendly
You need to:
SettingsOutput output_settings {
img_width=640;
img_height=480;
img_pixelAspect=1;
img_file="test_1_.png";
img_dir="C:\Users\Yavor Rubenov\Documents\3dsMax\renderoutput\";
img_file_needFrameNumber=1;
anim_start=0;
anim_end=5;
frame_start=0;
frames_per_second=1;
frames=List(
List(0, 5)
);
}
and you need to add a new line "img\_clearMode=5;" to it so you will get something like this:
```
SettingsOutput output_settings {
img_width=640;
img_height=480;
img_pixelAspect=1;
img_file="test_1_.png";
img_dir="C:\Users\Yavor Rubenov\Documents\3dsMax\renderoutput\";
img_file_needFrameNumber=1;
anim_start=0;
anim_end=5;
frame_start=0;
frames_per_second=1;
frames=List(
List(0, 5)
);
img_clearMode=5;
}
"C:\Program Files\Chaos Group\V-Ray\3ds Max 2019\bin\vray" -sceneFile=D:\path_to_scene\exported_file.vrsceneIn this way you can also use the Max output - it will work too.
As I said - that’s not very usable so we’ll try to fix it to work directly in Max soon.
Yavor, Great thanks! This animation is heading to around 3000 frames long now and the deadline is end of this month so this workaround will greatly help any render mishaps we find. Thanks for taking the time to find a workaround.
Got another problem and Render Mask.
I have a scene with a chrome washer moving down a Bolt.
This is what the normal full render looks like (note that the washer seem dark)
And this is with Render Mask Selected for the Washer and no change of materials.
So why does the Render Mask not match the full render? I have not changed anything at this point so it should be identical.
Note: Please note that I enabled the vray settings for camera exposure and then dial that back in post. I do it this way because this scene is usually 50% darker and noise was a huge issue to solve in that middle area, even with 3000 light cache samples and a 0.01 noise level. Over exposing fixed the noise issue while keeping render times under 4 mins per frame.
Thanks
Do you use the automatic exposure and white balance ?
Vray Settings → Camera → Automatic exposure was ticked for this shot yes. White balance was unchecked.
Auto exposure and render mask don’t work together - after you do the full render you can transfer the auto exposure settings back to the camera and then turn it off. That way render mask will give you the same result later on.
