VFB Spyglass Feature

[im.thatoneguy]

It would be amazing if the Vray VFB saved its current frame buffer to the HDD as it rendered. Or alternately and more advanced functionality would be to offer a TCP listener which would serve up the current framebuffer on demand. I imagine you already have this functionality built in for the purposes of Distributed Rendering so this would be exposing it to the public.

Applications:
- Integration with compositing applications so that you can do more advanced slap comps in real-time to see how say a VrayRT or even VrayAdvanced rendering looks in Nuke. Tweak lighting in 3ds max and with a TCP socket see the updates in real-time in your comp with roto shapes etc.
- Renderfarm 'peeking' so that I can look at a headless slave's progress to ensure it's the correct camera, correct render pass settings etc before a frame finishes.

[3LP]

I though that if you enable the *.vrimg saving process inside the VFB roll-out, vray actually saved each bucket as it's rendered straight to the drive.
This is also really useful when rendering extremely high ress images where the VFB can't hold in ram and you activate the "generate preview" checkbox.
Vray will only store a tigny version of the VFB in ram as a preview, and leave all the ram free for the render.
If you did had a way to look at the *.vrimg straight in nuke like you could with pdplayer, you would be able to see the progress in realtime like you describe.

This might work when you save to exr from there as well, haven't tried it, but if it does, then your solution is already available

Stan

[3LP]

Hey,
Just gave this a try actually.
You need to uncheck the "memory frame buffer" to have vray saving the buckets straight to the drive.
Unfortunately, for some reasons, I can't read the saved *.vrimg neither as *.exr untill the render is ended. (used pdplayer to try reading)

So I guess it's not already available out of the box, and it would be cool to have those images readable on the fly.

Stan

[piotrus3333]

memory frame buffer can be on.
to read vrimg file during rendering make a copy of it and than load to frame buffer.

[im.thatoneguy]

Great idea Stan! If you enable that and hardcode your MaxStart to a temp directory like \userfolder\spyglass\spy.vrimg and push that out to all artists you should be able to write tools to just always look for that. Of course that would mean that in order to create a reliable and predictable automated solution you can't use the Vray Raw Image Output which wouldn't be great. Alternately you would have to track down where the current framebuffer is being rendered to, which may or may not be a vrimage. That's not impossible but it would have its own drawbacks, especially if someone wanted to use Vray raw image output with say... exr. Definitely not something that thinkbox or the foundry etc could integrate into their products. It is though another piece of evidence though that all of the 'hard' parts in Vray are already in place, it's 'just' a matter of exposing the data to plugin developers and users.

[vlado]

Well, it's fully exposed to developers People have in fact written connectors to Nuke, for example. I myself am a bit hesitant as it is yet another plugin to support and we have enough of those already. But we could put an implementation on Github for those that want to play with it.

As for why you can't make the approach above work with OpenEXR - OpenEXR doesn't suppport reading of partially written files and it's not something that we can fix.

Best regards,
Vlado

[im.thatoneguy]

I would definitely sign up for a github repo. Does that mean it's already built into the Max/Maya plugins or does it require an additional plugin on both sides (viewer/server)?

[im.thatoneguy]

Ok a few other problems with the vrimage output approach.
- Progressive rendering doesn't work, since it doesn't write out until the render stops or completes. Is there a hidden maxscript flag to override that behavior?
- It forces a frame number so you have to tell the python script what frame is currently rendering or not to add frame number on a "Single Frame" checked.