Tracking 3D motion trackers

[Alan James]

Can anyone point me to a really comprehensive tutorial about how to track greenscreen footage ,import that information into a program like Maya and have that applied to the final render of the background?

Basically I am trying to make a movie like Sin City but am not totally educated in 3d motion tracking and need to learn a bit about it before I jump in head first. Anything at all about setting up tracking markers, tracking those markers, applying that info in a 3d rendering program, rendering the video and composting it all together would be great. The programs I have are After Effects 7 and Maya Unlimited so if the tutorial could be using them that would be great, but if not I’ll take what I can get. Thanx guys.

[Emre Safak]

You wanted comprehensive, so:

• Matchmoving: The Invisible Art of Camera Tracking
• Matchmoving: Essential Production Techniques Camera Tracking Techniques with Tim Dobbert
• Matchmoving: Object Tracking in Production Object Tracking Techniques with Tim Dobbert
• Matchmoving: Advanced Production Techniques Camera Tracking Techniques with Tim Dobbert

[Alan James]

I was hoping for something online that I could get my hands on for free but thanx for the links. I might have to invest in a book if I am going to learn this well enough to make it really convincing. If anyone can point me to a web site I would still prefer it.

[Anhar Miah]

Those Books, are great!

I would only like to add further that if you want to learn then get down and start doing it! that’s it, I too was once wondering and searching high and low for tutorials (there does not seem to be that many out there).

My tips:


1. Do not have too many tracking markers, just enough, also make sure that tracking markers are not to big, and use a distinctive colour such as yellow against green. A great Idea is to use "Post It(tm)" stickers.

2. The shot must have some perspective in order to track.

3. Do not do wild camera moves, like rotating the camera 360 degrees, this is mathematically impossible to calculate the 3d motion.

4. Take GOOD measurements and use Proper scaled units in your 3d app this way you can get an accurate sense of scale from virtual to reality.

5. Use a dummy to replace your actor in your 3d app, this can help to position and frame your 3d camera.

6. Spend time to make sure your track is correctly oriented, this is a MUST if you want to avoid further problems down the line.

8. Tracking shots are very time consuming :) so in a feature, unless you have lots and lots of time, keep them shots to a minimum, this is because so many shots can be static/ simple zooms/pan/rotates that are actually 2d moves and can be very easily done in any good comp application like combustion (with motion tracking or key framed) this will save you time and effort. Its not a surprise that a lot of VFX in industry are actually 2.5 D

In the end I found that just jumping in is the best way (and great fun) and you learn alot, and best part is you do not have to worry about making mistakes, because that’s how you learn. Next time round it gets better etc.

Anyway you can find an example of a green screen + tracking on a courtesy video I did a while back:

http://www.youtube.com/watch?v=sdDaqiV6WkI

Not the greatest, but the principle was there. I love this whole subject, right now I'm trying to better my skills in photo-real environment.

I hope that helps

Anhar

[Alan James]

From looking through your youtube account it looks like you are really into any kind of 3d effect. In your opinion what is the best program to get for someone who is starting out? I understand a lot of the concepts and how things work I just don’t know what buttons to push to make the program do what I want. So what’s the best to learn on?

[Anhar Miah]

That’s a tough question, too be honest its one that only you yourself can answer, of course there will be many that will swear by application Z or Y or even X. But in all truths, all apps do more or less the same things, it is only you as the artist that can make the most of the tools.

My experience in different 3d apps is limited, I first started toying with freespace, then blender and finally ended up with 3ds max.

I would say pick any 3d app that you want to grow with, and just digg in, there are many tutorials, BUT don't give up half way through UNLESS its not going anywhere.

And always remember that once you have mastered a 3d app migrating to another 3d app is not that difficult (just a different workflow) but the base concepts are ALWAYS THE SAME. :)

The only thing to mind is that different 3d apps seem to have carved up certain sections of the market, i.e Max is usually dominates the games dev side, where as Maya more Films, however saying that most of the time these companies will always use a bit of this and that and a ton of in house code, so its not such a clear way of saying this was done on app X since its always more complicated then that.

One last thing is do not be scared to experiment, and the fastest way to learn is doing tutorials, do as many as you can. Watch other peoples work to get ideas and motivation, and do not give up(sometimes it feels hard, but just do not give up) if things go badly, go back and try a different tutorial (and come back once your confidence grows).

I known its not much of an answer (you was probably hoping for one application or another) but as I said before, choose one and go on from there (Maya, Max, Modo, C4d, Lightwave, SoftImage, houdni) they are all great professional applications in the right hands they can produce anything.

Anhar

[Alan James]

Thanx for the advice. Actually that was about what I was looking for. This stuff is so much more complex then 2d composting and video editing. I’m a Robert Rodriguez type of guy in that I do everything. Right now I want to be able to write a movie with the confidence that I will be able to create 3D effects for it later. I keep having to write around 3D visual effects because I can’t make them look life like yet. At times I wish I could just have a “3D visual effects guy” that loves to do this stuff that I can count on to just make what I want happen, but I guess the only guy that really has that is George Lucas. Thanx again for the advice. I will probably be asking way way more on this subject in the future.

[Emre Safak]

I do not think this is a path you want to take alone unless you really enjoy it. You will be spending a lot of time behind the computer, rendering and all that. I would spend more time on the script and the lighting. Just a friendly word of advice...

[Alan James]

Oh yeah I do that anyways. I just want to make sure that the stuff I put in the script can actually be made in a reasonable amount of time. I write, produce, light, direct, edit, mix sound, and do simple visual effects. If I can turn that “simple” into “all” then I’ll be set when I get out of college. I do enjoy visual effects but right now all of the 3d stuff is way to time consuming for me to do myself being that I am tied up in all of the other parts. I just need to get faster and better at it and I guess the only way is to really jump in and practice.

[Lee Wilson]

PF Hoe


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