• Apple Motion

  stroking a motion path

  Posted by Electricpig on June 19, 2007 at 4:24 pm

  Before I bang my head against the wall after a very frustrating afternoon, can I stroke a motionpath over time? I’ve tracked a point in the scene, and I wish to stroke this track over time. I’ve tried everything I can read and find, but I’m chewing up hours at the moment.

  I just want to have a completely stroked track at the end as though I’d drawn a graphic infront of the lens. The timing and direction of the stroke should all be dictated by the tracker.

  thanks in advance

  Tjkobs7926 replied 18 years, 11 months ago 3 Members · 5 Replies
• 5 Replies

• 

  Electricpig

  June 21, 2007 at 10:16 am

  Just to be clearer, I want to start with a blank page, and end with a finished drawing, drawn in a single stroke. This stroke is just a plain red ink or similar, nothing fancy.

  The stroke is dictated by the track, drawing a diagram in the air.

  I can’t make motion be this simple, please help.
• 

  Doyle Rockwell

  June 21, 2007 at 5:26 pm

  Heya,

  Just to clarify: you’ve motion-tracked something in your footage and you want to use that tracking data to draw a stroke, as if a brush was following the tracked point?

  If so, just use a particle emitter. Use a Match Move behavior to have the emitter follow the track, and have the emitter release particles that have a Speed value of 0, so they just sit there. You’d need to extend the Life value so that the particles don’t die before the shot ends. Here’s a quick example: https://homepage.mac.com/specialcase/movies/trackline.mov

  Good luck with your project!
• 

  Electricpig

  June 21, 2007 at 5:48 pm

  Thankyou, that’s perfect. That was frustrating the hell out of me.
  Sometimes the ‘automatic’ side of Motion I find limiting, not able to get ‘under the bonnet’ enough, but dipping back into Shake where I feel totally at home after losing hours trying to solve my problem in Motion was a welcome relief.

  Ah, the joys of noodles…
• 

  Electricpig

  June 21, 2007 at 8:03 pm

  Just to add, I just upgraded to 10.4.10, and some weird display (or rather non-display) shenanigens has now dissappeared on my MacBookPro Core2. Suddenly a whole raft of stuff in motion suddenly makes sense again, and I can now see my particles, whereas before I couldn’t.

  Thanks again for your help, specialcase.
• 

  Tjkobs7926

  June 22, 2007 at 5:31 am

  Hello,
  I am struggling to use paint….I am no that good with motion to begin with…

  I want to use light, for example the present for light 2. I draw it on. And all looks well….

  But if I want to shorten the stroke or re-time the stroke I am lost.

  The only thing I can find are the key frames for the color, but that is long and difficult.

  Another item…when I draw the paint stroke on with the mouse or pen the computer can play it back at almost full frame….but when I put the paint stroke onto a shape or something else the computer seems like it can’t play it at all. I’ve got the MacPro Dual 2.6. with 256 MB of Vid RAM…? Don’t know if there is some that can be done to change that.

  Thanks as well!!!

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