I’m trying to use this code merged with http://www.mikechambers.com/blog/2009/06/24/using-bitmapdata-hittest-for-collision-detection/ , but it’s not working, it always returns false :-(. I did exactly what the 2 tutorials said. My objects have 3D transformation.

A ran into the exact same draw/matrix-problem when working on this thing: http://edvardtoth.com/flashfun/pixel-bender-depth-map-shader/

I’m glad I found this page just before I was about ready to go insane – thanks! :)

This is incorrect, that’s just a scaling Matrix with translation.

“The Matrix3D class uses a 4×4 square matrix”

Matrix3D is really a misnomer. Mathematically more appropriate to name it Matrix4D or 3D Affine Transformation.

“Matrix3D does not inherit from Matrix”

At this point a sane programmer should quit using flash.

When you purely use the matrix3d for transformation during the draw, you are not setting the correct transform on it to make it contained within the bitmapdata.

Although you could still probably make the 3d transform do that, I think it’s probably simpler to rely on the bitmapdata draw as it currently is, since the 3d transform during draw is a confirmed bug and is thus likely to be removed in future versions.

Collisions from top left work, but not from bottom right.

mike chambers

mesh@adobe.com

Yes! Passing in either an identiy matrix or null will work (just tested and confirmed).

I was so focused on how to get the corrected matrix in there, that I missed the easiest solution. Ill update the blog post to reflect this.

mike chambers

mesh@adobe.com