The first rule in using a shape or mask path as a motion path is that the layer containing the mask must be at the default position [thisComp.widh/2, thisComp.height/2)], the anchor point must be at the default position [thisLayer.width/2, thisLayer.height/2]; and the scale must be 100% and the rotation must be at 0º. If these conditions are not met then your mask or shape path will not line up with the motion path. The second rule is that the motion path will always start at the first vertex and proceed clockwise on the X and Y plane.
Here are some work arounds if you want to position a layer, scale it, then use the shape or mask path for a motion path.
- Auto trace your shape layer or layer with a mask using current frame and copy and paste the new mask path
- If you have a text layer you can create masks from text and pick a mask to use as a motion path
- If you have a vector layer you can create shapes from the vector layer after the vector layer is positioned
- If you are drawing a shape layer or modifying a shape layer do not scale or modify the layer's transform properties, instead double click one of the points on the path to bring up the transform tool and position rotate and scale your path to it's desired location then copy and paste.
If you need the motion path to be in the X Z plane then you add a 3D null, make the layer with the motion path 3D, parent the layer to the null, rotate the null in x and then remove the parenting.
As long as you follow rule 1 everything will be just fine.
All I did was follow along with the tutorial in the link below and it worked perfectly fine. Then the next day I come back and it doesn't and I have to precompose the text to get it to work correctly again. This makes no sense that it can work one day and not the next when I have changed nothing???
Check your text path by selecting it and pressing the u key twice to reveal the modified properties. Something is not at the default. You have changed something.
By the way, I just watched the whole tutorial and while it has some good ideas that are much better and more professional techniques that should be employed two great this project. Right off the top of the repositions I'm scales the text which means that his technique will not work. The text layer must be centered in the comp in at 100% scale to manually draw a path and successfully paste it to a motion path. This let me know right away that this was not a tutorial from a professional. You should never take as gospel a tutorial that says "this is good enough for the tutorial but I would never do this on a professional project."
A better way to do this project is to convert the text layer to shapes then copy and paste the shape path to motion paths. Your project isn't working because the rules, which are unbreakable, are not being followed.
I just made the emitter, the particular layer and the texts the same position and then it works correctly however I dont want to do this because I need the text to be where I need it to be. The only way is to pre comp the text before making the masks. This is ok but doesn't explain how yesterday I did not have to do this??
You are still not following the right workflow. There's a tutorial I knocked out uploading to YouTube right now.
Here's the steps:
- Create your text layer
- Position, rotate, scale your text layer to fit your design
- Create Mask from Text using the layer menu
- Select the path you want to use for the motion path
- Verify the first vertex of that path and change if necessary
- Select the position property you want to follow the path (Particular>Emitter>XY Position) and set a keyframe
- The position property will move counter clockwise. If you want it to go the other way use the keyframe assistant to time reverse the keyframes.
That's all there is to it. You plan, design, create your mask layer, set the first vertex, copy a mask keyframe, set a position keyframe and paste and you're done.
Sometime soon I'll post a whole series of better produced short tutorials on the basic workflow you should follow to use AE efficiently and professionally.
Ok thanks Rick for your help. I will try this.
The tut cleared everything up. Thanks.