1. Title Shadow and light 2. Paragraph Representations on the surface are dependent on imitation in the sense of an optical illusion. In order to fully represent the perspective in its functionality, not only light, but also the casting of shadows is important so that the illusion and creation of a third dimension is perfect and so that the eye can perceive this effect on a two-dimensional level. This strengthens the spatial understanding and makes “the work” easier to understand. For the representation of the shadow, "the location" of the lighting is of decisive importance and the course of the light-dark boundary of the shadow, which is determined by the physical laws of optics as a beam path from the light source via the object to the shaded area (see second section). Accolti also uses these auxiliary constructs in his representations in the third chapter and can determine the shadow cast b an object when designing an image with the aid of this representation geometry and thus create the construction of the shadow of a drawn object in a three-dimensional or projective representation on the two-dimensional image plane. The shadow can be created not only for central lighting and parallel lighting, but also for penumbra for multiple sources. In the third chapter Accolti also deals with a kind of light-dark contrast method based on the simple assumption that the shadow is darker than the light and shows it as hatching. However, in order for the shadow to be created precisely, it is important, as mentioned above, to understand the geometry and recognize its importance as one of the most important tools for creating the shadow and for achieving this three-dimensional effect. Descriptive geometry enables three-dimensional objects to be represented in two dimensions using a specific set of procedures. These theoretical foundations of descriptive geometry form planar geometric projections, which Accloti uses and thus creates an image generation technique based on imaginary, parallel projectors that start from an imaginary object and intersect an imaginary projection plane at right angles. These cumulative intersections create the desired image. These resulting techniques are important to architecture, but also to engineering, constructing, design, and art. Mastering these three aspects is an important foundation of architecture. Even if a lot is left to computers these days, nothing can replace the profound understanding of the written representation of three-dimensional optical illusions on two-dimensional levels, and is a prerequisite for everything else in terms of architecture. 3. Three Keywords Shading Geometry Optical effects / Illusion