Comments for sevenson.com.au

Comment on Separating Axis Theorem (SAT) Explanation by How to resolve collisions of compound shapes using SAT? | Q&A System

How to resolve collisions of compound shapes using SAT? | Q&A System — Sun, 11 Dec 2011 09:30:27 +0000

[...] SAT is a decent way to determine collisions between arbitrary convex polygons. You’ll even get the vector that is needed to resolve a collision. [...]

Comment on MathML Parser written in ActionScript 3 by Heloy

Heloy — Fri, 28 Oct 2011 17:00:21 +0000

Thank you so much, this is really what I need…even if I still don’t know how to adapt it to my code ( I already have a XML in which I would like to put the formulas).

Comment on Separating Axis Theorem (SAT) Explanation by Matt

Matt — Mon, 24 Oct 2011 01:25:06 +0000

In your article you mention that this technique does not provide the features of the two colliding objects. This is not true. This technique can be easily extended to provide the features of each object for further processing i.e. finding actual contact points.

Comment on Graph Classes written in ActionScript 3 by Matheus Castello

Matheus Castello — Mon, 10 Oct 2011 20:42:13 +0000

How I can use the GraphLine functions?

Comment on Separating Axis Theorem (SAT) Explanation by Andy

Andy — Thu, 11 Aug 2011 21:55:25 +0000

Ah I got it!
var shape = new Polygon();
shape = Polygon.basicPolygon();

Comment on Separating Axis Theorem (SAT) Explanation by Andy

Andy — Thu, 11 Aug 2011 21:48:13 +0000

I can get circle and box working, but not polygon. How do I create a basicPolygon?

Comment on Separating Axis Theorem (SAT) Explanation by Andy

Andy — Wed, 10 Aug 2011 14:54:44 +0000

I agree with meming – Great tutorial, but a simple useage example is always nice!

Comment on Testing Regular Expressions in ActionScript 3 by Marcelo

Marcelo — Tue, 26 Jul 2011 04:27:38 +0000

Congratulations! Great example. The source code of this application is open?

Comment on Separating Axis Theorem (SAT) Explanation by Dave

Dave — Fri, 10 Jun 2011 15:07:23 +0000

Nice work!

Just thinking though – is all that shadow detection really necessary? What about:

1) I know the centroid (middle) of the two polygons
2) I know the angle and length of the line between the two centroids (hypot of a triangle)
3) I can work out the point that’s closest to the other shape on one object.
4) I can use that point and the hypot to create a plane (using a line equation) that sits against my first shape but perpendicular to the hypot.
5) And then I can test if any points in the other shape are beyond that line – maybe by checking against the lines normal value (dot or cross product – I always get them confused)?

I don’t know if that’s any faster – just musing. Seems like more math but less work and no loops?

Comment on Separating Axis Theorem (SAT) Explanation by dysseus88

dysseus88 — Sun, 29 May 2011 18:03:40 +0000

Thanks for this powerfull code. It will be very helpful to me and I see I am not the first. I was looking for solid explanations about SAT and thanks to you, I know this is exactly what I should use. Please, could you publish source code of the above demo ? I tkink it would be easier for everyone to use your library in the future by analyzing this example.