help! dreaded collision mask!

I located the tile that is causing the problem, bc after removing it, construct doesn't complain anymore.

So I looked at the tiles collision mask... there's only three points in it, a small triangle.

I've placed the triangle in the middle of the tile instead of at the edge. Didn't solve the problem.

I've also placed any collision mask points close to the edge of neighboring tiles a bit further away. Didn't solve anything.

As I've pointed out, if I delete it the problem goes away, but then I loose the artwork for that specific tile as well, and the tile is part of a "spliced large foreground tile".

The message Construct gives me when I run the layout begins with the following line: "assertion failure: physics polygon separation resulted in no polys".

Grateful for any input, thx!

Turn off immovable?

I'm guessing you're using tiles imported into an animation? Anyhow, each animation frame has it's own collision geometry ... are you changing the wrong frame? ;)

I'm really not sure what the correct terminology is, so I'll do my best to describe it. I've seen this before when part or all of a polygon is "flipped", or its sides cross one another. C2 expects the polygon to have a solid shape. For example, you can't do things like take a square collision polygon, and switch its top two corners (or any two corners for that matter), because the polygon would not be a single solid shape. From what I gather, your polygon doesn't actually have crossing sides, but I'm guessing you accidentally turned the original polygon "inside out", or you switched the position of some of the collision points.

I'd suggest trying to "revert" the collision points. If that doesn't work, try reimporting the image (I believe the collision polygon will be reset), or post your capx so we can take a look.

Yeah, I "inverted" the triangle mesh, and voila! C2 works properly again. Thanks Zatyka!