Contents
How does an axis aligned bounding box work?
Axis Aligned Bounding Box means the box itself is always on the same orientation. To update the AABB you will need to recreate it each time the model rotates, and move it if the models positions changes. The box will change shape and size depending on the rotation and the model you use.
How to calculate the AABB from a bounding box?
Well, you should apply the rotation on the vertices of the original bounding box (for the purposes of the calculation), then iterate over all of them to find the min and max x, y and z of all the vertices. That would define your axis-aligned bounding box. That’s it at its most basic form, you should try and figure out the details.
Which is the minimum bounding box for a point set?
The axis-aligned minimum bounding box (or AABB) for a given point set is its minimum bounding box subject to the constraint that the edges of the box are parallel to the (Cartesian) coordinate axes.
How does the shape of the collision box change?
The box will change shape and size depending on the rotation and the model you use. If you want to have a rotating collision box than that matches up with the model, then that is completely different than an AABB, and you will need to look into the physics of your engine for that.
Can you pre-compute the ray box intersection?
In the eventuality of testing the intersection of the ray against many boxes, we can save some time by pre-computing the inverse direction of the ray in the Ray’s constructor and re-using it later in intersect. We can also pre-compute the sign of the ray direction which we can use to write the method in a much more compact form.
When does the cone intersect with the AABB?
If any edge does, the cone and AABB intersect. It’s sufficient to the check ray formed by the cone axis against the AABB; this is a pretty standard intersection test. It may actually be better to swap the order the face and edge checks; I’d expect the face checks to be faster that the edge ones, so you might be able to exit earlier.
When does a polygon intersect a box R?
A box R and a polygon P intersect if (and only if), when you clip P to the box R, the result is not empty, i.e., some parts of P are inside R. Thanks for contributing an answer to Game Development Stack Exchange!
What happens when you clip a polygon to a box?
Intersecting a polygon P with a box/rectangle R is the essence of clipping, so you could use a clipping algorithm. There are several, e.g., the Cohen-Sutherland algorithm . A box R and a polygon P intersect if (and only if), when you clip P to the box R, the result is not empty, i.e., some parts of P are inside R.
Which is a better fit of a bounding box?
(b) However, if the triangle’s vertices are first transformed from object space to world space and then bounded, the fit of the bounding box can be much better. An axis-aligned bounding box (AABB) is simply a rectangular parallelepiped whose faces are each perpendicular to one of the basis vectors.
When to use an aligned bounding box in ray tracing?
Such bounding boxes arise frequently in spatial subdivision problems, such as in ray tracing or collision detection. One common way to specify such a box is to provide two points Pmin = [ xmin ymin zmin] and Pmax = [ xmax ymax zmax ], as shown in Figure 11.61.