Photo frame and it's reflections in separate files or alpha-like channels - HOW?

[Tim in Hollywood]

Hi,

We are creating a very basic scene with a digital photo frame on the wall and a reflective floor. We have shots of this scene from many cameras. Due to the render times and different images, we cannot re-render all of them individually in V-Ray/3ds max. We need the availability to enter the digital photo frame content in post using Photoshop, After Effects, or another editing application.

I have attached a couple examples of both an example scene render and what we need to generate as a separate pass or separate channel. If possible/necessary, the alpha-like image can be two separate images (one with the only digital photo frame content, one with the reflection).

We have been able to generate what we need for the actual monitor content (using VRay object properties, then checking the "Matte object" checkbox and making "Alpha contribution" to -1.0).

If there is a better way to do this, we are open to it. We also need to get the reflection as a render element or separate channel or file.

We are open to any options. Any advice, tutorials, or suggestions will be greatly appreciated.

Thanks in advance!
Tim

[WobiNich]

Hmm, you may want to have a look at this:

http://3d-kstudio.com/scripts/tracks...RenderElements

[joconnell]

There's no really smart way to do it unfortunately besides the way you've done it - 100% reflective floor and a white object for the screen to be reflected. Either that or make the screen pure green to start off with, render a raw reflection pass and see if you can get a matte from that. For this type of stuff a pass manager is definitely the way to go though.

[Tim in Hollywood]

WobiNich: Thanks for the suggestion. It really looks promising. I installed the script, but it then game errors. Also, there appears to be no help file or description of the options. Any other suggestions?

[Tim in Hollywood]

joconnell:

Thanks for the advice. I know that this is possible in 3ds max scanline. I did this about five weeks ago with the scanline renderer. Unfortunately, immediately after completing that rushed project, I was out of town for a few weeks and didn't make good records of how it was accomplished.

From memory, it had something to do with a matte material on the floor. Does that help anyone's memory about how this could work?

[Tim in Hollywood]

I'd like to revisit this. We still have not found a solution to this problem. This has to be possible, somehow, some way...doesn't it?

I tried the 3d-kstudio script, but that didn't seem to work as I had hoped.

If anyone can offer some new suggestions, I would be very grateful!

[nirsul]

I think I manage to achieve what you were looking for:

1. Floor plane has a simple Vray material with reflection applied to it.
2. Create a photoframe and place it where you need it - make a duplicate (change its rendering settings as in the attached image) and move it to the same height but under the floor (so a photo at 100 cm will be mirrored to -100)
3. Duplicate the floor and apply a matte material to it.
4. select the matte duplicate and right click and select Object Properties
5. press the By Layer and change to By Object.
6 Uncheck all of the options except for the Renderable (see image attached)
7. In the Render Setup dialog - go to Render Elements and add a MultimatteElement
8. In it chnage to a number similar to that of the materila applied to the photoframe
for example 4 (,ake sure the materila is set to 4 in its material ID channel)
check all checkboxes for the MultiMatteElement. (see image attached)
9. I suggest you render the scene twice - once with the Matte object turned off for the
beauty render and once with the floor turned off - to get a smooth reflection element
I tried it with both turned on and I got strange floor (because the 2 objects were rendering the same pixels)
also the floor reflection element was to noisy.
10. I attached a simple MAX scene (max 2011)
11. the attached image showing the rendered element result has an invisible object hiding the floor reflection - you will see it in the MAX scene - it can be removed nad was only added to check its influence.

NIR