• Adobe After Effects

  Hit by car effect

  Posted by Moviemaker2727 on June 23, 2007 at 2:58 pm

  Hey, im trying to do that AE classic hit by car effect, where you film the victim getting hit and then the car driving by. My mistake was that in between the time i filmed the vitim and the time i filmed the car the camera moved a fraction of an inch. What i have been trying to do is to draw a mask around the car and then move the mask with the car (because although the shots are positioned slightly differently the car still stays on the road but everything around the car and me looks really blurry cuz there are two of em). My problem is that when i try to move the mask i cant. How do i move it or is there a better way of doing this. I can reshoot the shots if i need to

  thanks

  Michael Zoppo replied 18 years, 10 months ago 3 Members · 2 Replies
• 2 Replies

• 

  Erik Pontius

  June 23, 2007 at 5:52 pm

  On the layer with the mask…hit “M” to bring up the Masks for that layer. Click on the mask name (ie. Mask 1). All the nodes along the mask should be small solid squares. Take your mouse and position it directly over one of the lines in the mask..the cursor should change from white to black, click and drag to reposition the entire mask.
  To move only one node, click on the layer itself, the node points shoudl change from squares to diamonds. Then very carefully click on one of the nodes, it will turn into a solid square, changing the unselected points to hollow squares.

  You can animate the position and shape of this mask by hitting “MM” to bring up all the mask properties and clicking the stopwatch for “mask Shape”, start setting keyframes by moving down the timeline adjusting and adding nodes with the arrow and pen tools.

  You might be able to compensate for the camera move by lowering the opacity of the top layer slightly to then be able to align both shots.
  Duplicate one layer drop it to the bottom of the stack, scale it up a bit to cover any edges exposed by your realignment.

  Erik
• 

  Michael Zoppo

  June 24, 2007 at 11:44 pm

  I would also like to add that it seems as though you are masking the car? It might be easier to mask the actor , and then on impact follow the actor with the front of the car, i.e transform the rotoscoped actors position with the hood of the car, and if the car is driving fast enough it will look legit.

  Mikey

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