• Adobe After Effects

  help with space tranforms

  Posted by Jason Brindley on January 20, 2022 at 7:03 pm

  I’m trying to make a few simple video compositions for an art project. I know the basics of Maya, but I’m a complete newbie to After Effects.

  In essence, it’s a simple screen replacement. But using a 3D scene instead of video footage seems to have complicated things massively.

  What I’m trying to do is probably simple by compositors standards, but I’m already completely bogged down by expressions and layer space transforms. I could do with a little hand-holding; I’ve no knowledge of code or programming at all – I’ve searched all over the place, but the documentation and tutorials I’ve found are way over my head.

  What I’ve managed so far (see attached pics) –

  – Created a Maya scene with a simple plane and camera animation;

  – Attached locators to the corners of the plane, imported them and the camera data into AE

  – aligned the data over the rendered sequence, so have nulls giving corner position data,

  Next, I wanted to place a square animated GIF over the plane. I tried parenting and corner pinning, but it didn’t work properly. I found the following expression to help –

  layer = thisComp.layer(“null_bttmRight”);
  layer.toComp(layer.anchorPoint);

  I didn’t understand it but pasted it in and fluked it. Although this pinned the corners, the transform controls for the GIF layer are still in the top left corner. I’ve asked around, and someone suggested I might need toWorld or fromWorld… but no explanation on how to do this, and I’ve been stuck at this point for weeks –

  I could do with an idiot-proof explanation of how I’d use fromWorld to move the transform controls back over the GIF (if this is indeed the right thing to do). I’ve been reading about layer, comp and world space, expressions, values
  and arguments. The different spaces AE uses kind of makes sense now,
  but I’m entirely baffled by expressions – what I need to type and where
  they need to go.

  Thanks

  Jason Brindley replied 4 years, 7 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Jason Brindley

  January 20, 2022 at 7:09 pm

  didn’t seem to attach the pics –

  

  

  

  

  
• 

  Walter Soyka

  January 21, 2022 at 3:09 pm

  Corner-pinning is an effect applied to a layer, it is not an intrinsic property of the layer itself. The actual layer’s anchor and position (and thus its transform controls) will not change when you apply a corner-pin effect.

  Instead of sending 4 nulls from Maya to Ae to do a 2D corner pin, you could send the Maya camera and 1 null at the center of the plane, then use those to drive the GIF as a 3D layer. Then the object would be set in the scene via its native transform properties.
• 

  Jason Brindley

  January 21, 2022 at 7:10 pm

  Thanks for the insight, Walter. It’s a great relief to learn I don’t need to worry about the layer transforms.

  And it makes a lot of sense to use a single locator and a 3D layer; it’s something I’d thought of doing, but as nobody else had suggested it to me I assumed it was a daft idea. I’ll try that method out now.

  Thanks again

  j

Reply to this Discussion! Login or Sign Up