Skeleton bounding rectangle

terryhau

I want to be able to cull skeletons by comparing the camera rectangle with the skeleton rectangle.
Something like

if(camera.rectangle.overlaps(skeleton.rectangle))
    render(skeleton);

Would it be possible to calculate the bounding rectangle of a skeleton when it is loaded?
Since the rectangle changes if the skeleton is animated, perhaps calculate some kind of worst case rectangle?

Nate

Here's Java code to do it:
www.esotericsoftware.com/forum/viewtopi ... p=147#p147
It's slightly outdated, but that is how it works.

terryhau

Thanks Nate.
That looks a bit too expensive to call every frame for every skeleton.

What I'll probably try is, calculating the rectangle once, storing it, and then translate the rectangle as the skeleton moves. Even though the rectangle becomes invalid after animating the skeleton, I think it's close enough that it won't matter. Or maybe just add 20% to the size of the rectangle to account for animations.

Nate

Another approach is to use an image in the editor that you don't draw at runtime. Then get the vertices of that attachment and use them for hit detection. This is nice because the attachment will move with the bones. This is essentially what the bounding box feature will do. You will need a point-polygon test since the vertices aren't an AABB.

terryhau

That's a good idea.

So eventually there will be a built in bounding box, and I won't need the transparent image ?

Nate

Yup!