Rendering with Region or Render Mask on clears all channels on the Frame Buffer.

[Dominic_Patel]

Hi,

I keep running into this issue where if attempt to render a region or use the render mask to check certain parts of the image the entire frame buffer resets and I loose all the previous channel information. I have previous render set to unchanged in the system rollout. I tend to run into the issue when I've been working on a scene for a while and I've imported a bunch of models for furniture, have lots of shaders etc. The only way I can seem to rectify the issue is by merging the latest iteration of the scene into a new model. Last time it appeared to start happening after I accidentally clicked 'Duplicate to MAX Frame Buffer' at the top of the VFB.

I've noted this thread for Maya but the advice isn't relevant to MAX. We're running 3DS Max 2017 sp3 and VRay 3.60.03

Is this a bug or am I have altered a setting somewhere without realising?

Thanks,
D

[yavor.rubenov]

Hello,

I can't seem to reproduce the issue on a simple scene. Can you share a scene that shows the issue with our support - you can replace the geometry with something simple as long as the issue still happens.

Best regards,
Yavor

[Vizioen]

I had something similar lately on a scene. I saved an image to my VFB. A few days later I wanted to render a region so I loaded the image in the VFB, selected a region and rendered. Result was as OP describes, VFB was cleared only the region was there.

[Dominic_Patel]

Hey Yavor,

I've deleted everything out of the scene bar the boxes I used a guides for people placement, Cameras and Lights. I just did a quick test and the issue seems to still be happening. I cant upload the file on here for some reason but here's a wetrasnfer.

Thanks,

D

[yavor.rubenov]

Thanks for the scene - I reproduced it here.
Its an old bug that we haven't yet fixed unfortunately - if some of the render elements have names with more than 64 characters some internal checks go wrong and we decide that the render elements have changed and we have to clear the old results.
In your scene - some of the multi matte elements have long names that cause the issue.

I'll add a note to the bug report and write back here when there is some progress.

Best regards,
Yavor

[Dominic_Patel]

Ah! Yeah I'm using the AutoMultiMatte script to generate them. I could probably just rename with numbers or something for now. But it's good to know whats causing the issue.

Thanks for your help its much appreciated. And yeah, it would be great if you could let me know when there's some progress.

Best,
Dominic

[stevesideas]

Rather than start a new thread I thought I'd add to this one. I'm still experiencing this issue. I saved a render to the VFB history. Came back the next day to change some materials, loaded the image into the VFB, selected objects for render mask and the screen clears to black before the render mask items start rendering. Not great! Nothing else changed, same res etc.

[hermit.crab]

Rather than start a new thread I thought I'd add to this one. I'm still experiencing this issue. I saved a render to the VFB history. Came back the next day to change some materials, loaded the image into the VFB, selected objects for render mask and the screen clears to black before the render mask items start rendering. Not great! Nothing else changed, same res etc.

Indeed, the issue seems to be present when a saved image's render element's name has more than 64 characters too. Not sure if there's a workaround for this.

[stevesideas]

Indeed, the issue seems to be present when a saved image's render element's name has more than 64 characters too. Not sure if there's a workaround for this.

Is this a windows type limitation or is this something that can be corrected in the software? I mean, for me one of main reasons of having Vray history is to be able to have the option of rendermasking specific objects without having to render the entire scene again. It can add hours to a project if I have to do this. My filenames aren't long but I assume it takes into consideration the path to the file name also which can be a network path...

[hermit.crab]

Is this a windows type limitation or is this something that can be corrected in the software? I mean, for me one of main reasons of having Vray history is to be able to have the option of rendermasking specific objects without having to render the entire scene again. It can add hours to a project if I have to do this. My filenames aren't long but I assume it takes into consideration the path to the file name also which can be a network path...

The issue is related to the names of the Render Elements themselves. If yours aren't as long (64 characters +) maybe something else is going on and it would be best to send the scene for troubleshooting.