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View Full Version : What's the best way to import chromakey info into 3dsMAx?



Deer Film
02-12-2013, 05:20 PM
Hi
Shot some green screen footage. After I chroma key out my green, how do you export your footage to 3dsmax? I have always exported my original footage as an uncompressed avi and the alpha or black and white footage out as an uncompressed avi too. Then in max, I add the black/white footage as the opacity.
Are these the steps for best result?
Around my edges in Max, I am getting green spill, but I didn't see it in vegas. I will try the same steps from After Effects tonight.

After I am done in Max, I export my 3dsmax footage as an uncompressed avi back into Sony Vegas or After Effects to finish my production.

Second question, what chroma key software/program do you think offers the best control and result?
I have used Sony Vegas BBC chroma key, but I think After Effects Chroma key is better. I am open to new things.

Working between Sony Vegas, After effects, and 3dsmax, do you think uncompressed avi's is the best to move around.

Thank you for your time.

danjenkins
02-12-2013, 07:06 PM
It's usually a better workflow to integrate video footage into a 3D environment at the compositing phase (that is, in After Effects). What type of shot are you trying to accomplish and why are you bringing 2D footage into a 3D package? It can be done (i've tried it a few times with different levels of success), but it's way easier in a compositing program.

But the best workflow I found is exactly what you outlined, assign the video to diffuse then a track matte for the transparency. I am unfamiliar with Vegas but if it's anything like Keylight (in AE, which is a pretty good keyer to address your question about keying software) it's applying some spill suppression when it creates the track matte. If you are loading your raw footage into the diffuse channel then it's not getting the benefit of that spill suppression. You would need to either use the keyed footage in the diffuse, or another color corrected version (ie. with a spill suppression applied).

I would say that AE is probably a better piece of software for keying. Check out Andrew Kramer's tutorials on Keying, he uses Keylight in AE and explains it all way better than I could. http://www.videocopilot.net/tutorials/basic_color_keying/

As for the format question, i'm not an expert on that. Obviously you want to keep as much quality as possible, so staying uncompressed sounds like a good approach. But those AVI files get real big in a hurry and will make Max slog while trying to play back and render. I've used quicktime in the past, and h.264 didn't look too bad to me.

Deer Film
02-12-2013, 08:05 PM
Thank you, I will check out the things that you wrote.
What I am doing, is filming myself as the actor in front of a green screen. Then I apply that footage to a plane in Max and have 3d elements in back and in front of the plane. That way it gives the illusion that I am in a different place. It works well for me. I have gotten better with my lighting the green screen, but I had some footage that needed lots of chroma work, and I have used Primatte in After Effects and BBC Chromakey in Vegas. I think Primatte gives more control, I just need to work with it more this week.
thanks for your help

danjenkins
02-12-2013, 09:30 PM
Just for your info, in a production environment, that exact process would be done in AE or something else like Nuke. You would either render out the elements that are in front of the footage and behind the footage in separate layers and just put your footage between them. Or a more advanced way is to render out a z-depth pass and use that to create masks for the footage, giving the illusion of depth.

Once again I refer to VideoCopilot to better explain. http://www.videocopilot.net/tutorials/depth_compositing/

Deer Film
02-13-2013, 10:54 AM
I thought about what you wrote, and it makes a lot of sense to put it all together in AE. Then I can control any small changes to my chroma-key and have a lot more control. I can just put in a test footage on my plane in Max to get everything aligned right, and like you said, export the background and foreground as 2 seperate footage.
May I ask what file format and how you export the foreground, because I want it to include an alpha. I assume a TGA with alpha.
Thanks for opening my eyes to a new way of doing my production.

danjenkins
02-13-2013, 12:42 PM
TGA sequence is a great choice.

Give this workflow a shot and see if it works for you. If you like it then great. But hey, if you like your way better then do that. As long as you get the results you are looking for.