TransformTransformPoint

TransformTransformPoint is a term used to describe the operation of applying a transform to a point, typically converting from local or object space to world space. In many graphics and game development frameworks this functionality is exposed as TransformPoint or similar methods on a Transform or Matrix class. The phrase itself is not a universal API name, but the concept is widely implemented.

How it works: A transform encapsulates translation, rotation, and scale. Transforming a point means multiplying the point by the transform’s transformation matrix, yielding a new point in the target space. In homogeneous coordinates, this is p' = M × p, where p is the point [x, y, z, 1] and M is the 4x4 transformation matrix. The result accounts for position, orientation, and size changes defined by the transform. Some APIs distinguish transforming points from transforming directions; points are affected by translation, while directions are not.

Usage and examples: In Unity, for example, TransformPoint converts a local point to world space: worldPoint = transform.TransformPoint(localPoint). There is also InverseTransformPoint to go in the opposite direction. Other frameworks offer similar functionality via Matrix.TransformPoint or a method on a Transform-like object. When a hierarchy of transforms is involved, child transforms are applied on top of their parents, so a point in a child’s local space is finally expressed in world space after traversing the chain.

Related concepts: TransformDirection (for direction vectors without translation), InverseTransformPoint, and Matrix4x4.TransformPoint. These tools are fundamental in rendering, collision detection, and spatial reasoning.