I was trying to make a defocus pull matte by starting with a black solid (comp size) and using the 4 Color Gradient effect on it, with the color points set to white and black so that I could place where I wanted the blurring to occure. I used the Compound Blur Effect on the Layer that I wanted to blur and chose my "defocus matte" as the Blur layer.
I tried precomping the "defocus matte" layer and again NOTHING HAPPENED. Nothing Blurred.
What am I doing wrong.
Also is there a better way to create a defocus matte. The four points of the color gradient didn't quite follow the outline that I wanted. Do I need to create the Defocus matte in Photoshop or Illustrator.
Thank You in Advance
Using CS4 on a Mac
Make sure you precompose the matte layer, and be sure to "move attributes" into the precomp.
Yes, PS is probably a better way to build specific, complex mattes. Or use the paint tools in AE...?
The 4 Color is not the best tool. All compound effects rely only on luma values ad ignore chroma information. And remember the blur layer is sampled before all effects are applied, unless, as Andrew notes, you carefully precompose.
The best compound effects are the result of careful experimentation. Compound and grayscale effects are one of the more powerful control systems in After Effects. They can drive animation systems in Shatter. Very cool.