1/8/2023 0 Comments Ray box intersectionThe choice of the type of bounding volume for a given application is determined by a variety of factors: the computational cost of computing a bounding volume for an object, the cost of updating it in applications in which the objects can move or change shape or size, the cost of determining intersections, and the desired precision of the intersection test. In computer stereo vision, a bounding volume reconstructed from silhouettes of an object is known as a " visual hull." Common types The basic idea behind this is to organize a scene in a tree-like structure where the root comprises the whole scene and each leaf contains a smaller subpart. To obtain bounding volumes of complex objects, a common way is to break the objects/scene down using a scene graph or more specifically a bounding volume hierarchy, like e.g. (Onscreen objects must be 'clipped' to the screen, regardless of whether their surfaces are actually visible.) In either case, it is computationally wasteful to test each polygon against the view volume if the object is not visible. This is because an 'object' is typically composed of polygons or data structures that are reduced to polygonal approximations. Testing against a bounding volume is typically much faster than testing against the object itself, because of the bounding volume's simpler geometry. In collision detection, when two bounding volumes do not intersect, the contained objects cannot collide. These intersection tests produce a list of objects that must be 'displayed' (rendered rasterized). Similarly if the frustum contains the entirety of the bounding volume, the contents may be trivially accepted without further tests. If the ray or viewing frustum does not intersect the bounding volume, it cannot intersect the object contained within, allowing trivial rejection. In ray tracing, bounding volumes are used in ray-intersection tests, and in many rendering algorithms, they are used for viewing frustum tests. Bounding volumes are most often used to accelerate certain kinds of tests.
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