3 Render Mask Requests

[ajroane]

1) Allow the render mask to be calculated using the viewport background as a backplate. This would help to eliminate the dark edge caused by blending the mask against a black backplate.
2) Create an option to split multiple render masks by ObjID, MatID, Object, Texture, Layer, etc.
3) Allow the 'Selected' render mask option to render over Backburner. Currently, the render crashes if the mode is set to Selected and rendered using Backburner (using 3dsMax 2015).

Thanks,
Andrew

[vlado]

For #3 we will fix the crash, but there's no easy way to make it work - 3ds Max does not store the selection set in the scene.

#2 you can sort of do that already with the Object select render element - make sure all the objects that you want rendered are in the mask, and then you can split those by object or material ID using the Object select elements.

For #1, I'm not sure I understand. If you clear the VFB to black, the objects will be rendered in a way that allows perfect compositing over a black background. There will be problems if the VFB has some non-black image before. Btw, you can load a viewport grab into the VFB using MaxScript.

Best regards,
Vlado

[AlexP]

For #1, I'm not sure I understand. If you clear the VFB to black, the objects will be rendered in a way that allows perfect compositing over a black background. There will be problems if the VFB has some non-black image before. Btw, you can load a viewport grab into the VFB using MaxScript.

I think the problem is, you cant cleanly composite over a non-black background, if that makes sense.
I think it would be useful if we could load up a previous render into the VFB from an exr or jpg and then render over that so the edges would blend nicely.

[vlado]

I think the problem is, you cant cleanly composite over a non-black background, if that makes sense.

Not really. It should still composite perfectly if you use premultiplied alpha.

I think it would be useful if we could load up a previous render into the VFB from an exr or jpg and then render over that so the edges would blend nicely.

You can do that with a MaxScript.

Best regards,
Vlado

[MoonDoggie]

Should you really need to find/run a script to do this task?

[AlexP]

Should you really need to find/run a script to do this task?

Indeed.
Would be good to just have the capability in the VFB

[vlado]

If you are going to automate this (which I'm assuming you will), it will need to be scripted anyways.

Best regards,
Vlado

[m_hinks]

I've had this issue in photoshop as well. I've mentioned to Vlado and he looked and said its all working correctly. I think its more an issue with Photoshop and alpha blending.

[AlexP]

Im must be missing something here, but how do I get the image to stay in the vfb so I can render over the top?
Everytime I hit render it is blacked out before the LC starts.
Previous render setting set to "unchanged"
Turned off "show calc phase" of LC

[vlado]

Im must be missing something here, but how do I get the image to stay in the vfb so I can render over the top?
Everytime I hit render it is blacked out before the LC starts.

Can you tell me step by step what you are doing? This works fine for me generally.

Best regards,
Vlado

[AlexP]

So, click the button to open an image in the VFB, pick an exr or tiff file.
Image appears in VFB.
Select an object, and set it to render mask - selected. (or a region)
Hit render.
Image goes black and then render begins.

Im sure its something somewhere I have not ticked?

[vlado]

Still works for me. It might be something specific to that scene - do you think you can send it to support@chaosgroup.com?

Best regards,
Vlado

[AlexP]

I can indeed

[re:FORM]

If you have added a new render element, the vfb will revert to black when rendering. Perhaps that's what's causing your problem?

[AlexP]

Not this time. But probably an equally annoying user error.