projection is used. To limit the number of displayed objects, two additional clipping planes are used; The visual volume is therefore a truncated pyramid (frustum). The parallel or orthogonal projection is used, for example, for technical representations because it has the advantage that all parallels in the object space are also parallel in the image space, and the surfaces and volumes are the same size regardless of the distance from the viewer. Maps use, for example, an orthogonal projection (so-called orthophoto), but oblique images of a landscape cannot be used in this way - although they can technically be rendered, they seem so distorted that we cannot make any use of them. The formula for calculating a perspective mapping matrix is: With h = cot (fieldOfView / 2.0) (aperture angle of the camera); w = h / aspectRatio (aspect ratio of the target image); near = Smallest distance to be visible; far = The longest distance to be visible. The reasons why the smallest and the greatest distance have to be given here are, on the one hand, that this distance is divided by in order to reach the scaling of the scene (more distant objects are smaller in a perspective image than near objects), and on the other hand to scale the Z values to the range 0..1, for filling the Z-buffer. This buffer often has only a resolution of 16 bits, which is why the near and far values should be chosen carefully. A too large difference between the near and the far value leads to so-called Z-fighting because of the low resolution of the Z-buffer. It can also be seen from the formula that the near value cannot be 0, because this point is the focus point of the projection. There is no picture at this point. For the sake of completeness, the formula for parallel projection (orthogonal projection): with w = width of the target cube (dimension in units of the world coordinate system); H = w / aspect Ratio (aspect ratio of the target image); near = Smallest distance to be visible; far = The longest distance to be visible. For reasons of efficiency, the camera and projection matrix are usually combined into a transformation matrix so that the camera coordinate system is omitted. The resulting matrix is usually the same for a single image, while the world matrix looks different for each object. In