Vray 5 - Vray Clipper is unintentionally moving with camera when rendering with any output other than Single Frame

[adamf13]

I'm rendering an animation where I have a vray camera linked to a dummy which is animated. I also have a stationary vray clipper object in the scene. When rendering single frame, the vray clipper appears in the correct location no matter which frame number I render. However, as soon as I render a sequence using "Range", "Active Time Segment" or manually inputting a range in "Frames", the vray clipper moves with camera.

I have also tried placing a stationary dummy in the scene and linked the clipper to the stationary dummy, which did nothing. However I really don't think it has anything to do the clipper accidentally getting animated seeing as though it works fine when rendering only a single frame.

This is a rather significant problem, cause I can't really rendering each frame individually in the whole animation.

[adamf13]

I may have figured out a workaround. I added a keyframe on frame 0 and one at the end of the animation for the vray clipper. It seems rendering by range is working now cause the clipper is staying in place. It's just bizarre that without a keyframe, it would move with the camera when rendered by range.

[matanov]

Can you please strip the scene and send it over?

[geoffneck]

I've encountered this today except with a mesh as the clipper and was left completely puzzled as it definitely feels like its a bug. Just one thing to add to adamf13's post, when adding a keyframe to the clipper, make sure its moving the smallest amount over the animation... just adding a keyframe without movement did not work for me!

[secondplace]

This bug is still prevalent in the latest V-Ray version.

The Clipper actually seems to stay in place but the cut edge seems to move along with the camera.
The workaround mentioned above works but only as stated by geoffneck if the VrayClipper has a tiny bit of animation. It must be triggering the VrayClipper position.

I've made this quick picture to illustrate the problem


I can provide the scene if needed.

[hermit.crab]

secondplace Could you attach the scene here?

EDIT: Nevermind, matanov reproduced it.

[matanov]

The initial complaint was about a regular (plane) clipper and it is already fixed. The mesh mode requires extra love though, I've logged it as VMAX-11714.

[secondplace]

In case people run into this issue until it's fixed i made a little Powershell script to create a batch render.
Since single frames work fine it will basically render your sequence by renderering each frame separate. I guess this would also work in maxscript but i don't know enough about it.

$Output = "C:\Folder\Batchfile.bat"
$Sequence = 0..100
#$Sequence = @(10,25,66,90)
$Line2 = '"C:\Program Files\Autodesk\3ds Max 2020\3dsmaxcmd.exe" "C:\Folder\File.max" ^'
$Line3 = '-outputName:"C:\Folder\File.tif" ^'

$Batch = @('@echo off','')
for ($i = 0; $i -lt $Sequence.Count; $i++) {[INDENT]$Line1 = 'echo Rendering Batch: Frame ' + $Sequence[$i]
$Line4 = '-showRFW -frames:' + $Sequence[$i]
$Batch += $Line1,$Line2,$Line3,$Line4,''[/INDENT]
 }
$Batch | Out-File -FilePath $Output -Encoding 'utf8'

Copy the above code and save it into a *.ps1 file.
The Paths obv need to be changed to be your own.

The reason i also included the "#$Sequence = @(10,25,66,90)" is because some frames sometimes give errors. If this happens they can be set manually as in the example. remove the "#" after!

Nothing fancy here but might save you some grey hairs