Posts Tagged ‘Compositing’

Tips – Offset tracking in After Effects

Wednesday, July 22nd, 2009

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10mins 49sec 29meg Quicktime H.264 MOV


Alrighty, back with another one of those block rockin’ beats to quote those Englishmen, the Chemical Brothers.

Last time we looked at offset tracking in Shake, a relatively straightforward and easy affair . . . not so in After Effects as it turns out. Hopefully this will help you out. Thanks to my co-worker Dan Bryant for showing me this method which I then finally found somewhere else on the net with Carl Larsen’s video over at Creative Cow. If you are an After Effects user and aren’t checking Creative cow, then shame on you!

Tips: Offset tracking in Shake

Sunday, June 7th, 2009

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5mins 55sec 36meg Quicktime H.264 MOV

 

Offset tracking?  What about tracking in general, Matt?  Hold your horses and steady on!  I freely admit that this is an old tutorial I did for the University course I taught, so apologies to my previous students . . . please don’t let this make you feel any less special.  You are all unique snowflakes!

 

Actually the real reason is that upon reflection my original tracking video might raise the ire of Teh Appel Corporation as I used the standard footage provided in the shake tutorial book . . . soooooo, rather than risk a multi-billionaire dollar lawsuit and put Steve Jobs already strained health under more stress, I will look at doing a re-edit with some techniques I learned on ‘Australia’.  

 

Now, these concepts can be applied to pretty much any compositing software.  As far as I know they all have the ability to offset or append a search region.  Why do we do this?  The main reason is because your main tracking points become obscured or head offscreen.  The thing is, as an aspiring compositor or 3D person, you might not know that this is possible, so you will be fighting your footage trying to get “the perfect track” on a point when it either just can’t be done or you can get a better track quicker and with less time wastage by choosing better tracking data at some point in your clip.

 

So, without further delay, check it, like, totally out.  As always, comments, questions and additions are welcome.  Only unnecessarily over the top profanity is frowned upon.

 

Offset tracking.  Sexxy, no? No.

Offset tracking. Sexxy, no? No.

 

 

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Tips: Using RGB mattes in CG compositing pt2 – the video!

Sunday, May 17th, 2009

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16mins 38secs, 54meg Quicktime mp4 mov

 

I finally got my desktop fired up and grabbed this video I made last year for class.  I have a 50meg version of this I will try and get up soon if 80meg is too big.  I have used Simon Reeves’ excellent breakdown on his website www.bankaffairs.com.  Check it out for some very clear examples of using RBG passes for compositing in CSI Please note that all images are copyright Simon Reeves and are to be used for education purposes only.  Check out Simon’s main site at www.simonreeves.com.

 

Note: for clarity (and my own workflow), I have reordered the channels of the RBG passes before feeding them into nodes.  You don’t have to do this in Shake.  In the node being masked you can choose which channel you want to use as the mask.

 

Images (c) Simon Reeves

Images (c) Simon Reeves

Tips: Using RGB mattes in CG compositing

Sunday, April 12th, 2009

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This topic came up recently on CGTalk and I also covered it in the compositing course I taught at the Queensland College of Art.  I do have a video screencast as well that I did that I will try and dig up as I think it is on my main PC which is in pieces at the moment.

 

Inspiring, no?

The question was: “How do I use ID passes (or RGB mattes) in my compositing?”

 

I guess the first place to start is to remember that compositing is all about colour channels.  Pretty much the first thing you do when you get your plates is check the colour channels (red, green and blue) to see what kind of information is there.  When you are working with straight CG images, it is a bit different.  You will often have various black and white mattes rendered out for you to isolate various objects in a scene.

 

As we (hopefully) know by now, mattes are essentially greyscale (grayscale for you North American types) images that affect an area of your based on the intensity of the pixel colour value, usually with pure white affecting the change the most and black affecting the least.  These can be things like images, patterns, keys or rotoshapes.

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