What is the specific difference between a structural sketch and a chiaroscuro sketch?

Structural sketching is to grasp the coordination of the structure, shape and size of the object, and make a mold, which is the basis of sketching. Chiaroscuro is based on the change of the angle of light, and chiaroscuro is destined for the quality of the object being drawn, which is the icing on the cake. Work hard, classmates, come on!

Structure is the need to draw the place that cannot be seen by perspective Perspective is to better understand the structure of the object Light and shade is to draw the appearance of the object and the relationship between light and shade that the eye looks directly at.

<> "The relationship between light and dark is a very important part of sketch painting, and its most basic function is to express the relationship between volume and space. The relationship between light and dark is divided into five major levels, which is often said: "five tones of light and dark".

The five tones of light and dark include: highlight, the brightest point on the light-receiving surface.

Bright surface: refers to the layer between the bright and dark gray surfaces of the light-receiving surface.

Gray surface: refers to the level between the light side and the boundary between light and dark.

Light and dark junction: refers to the turning point of the light and dark sides, and the general light and dark junction is the heaviest place.

Dark Side: Contains the backlit side of the object, reflections, and shadows.

These five levels can actually be summarized into three levels: the light side, the gray side, and the dark side. Of course, there are more and finer levels in these five tones, which can be summarized and distinguished according to the degree of detail of the painting.

Let me first explain the relationship between light and dark of objects through the cube. You have to have light before you can have light and dark, so I'm going to assume a light source direction for now. The area where the light can shine is called the light-receiving surface, and the place where the light cannot shine is called the backlit surface.

The backlit side includes the dark side and the shadow side, and the lighted side includes the light side and the gray side. The shape of the shadow is directly related to the direction of the light and the occlusion of the object. According to the principle of near real and far virtual, the contrast between the front, especially the junction between light and dark, should be strong and clear, and the contrast behind should be weak and blurred.

Also, the shadow gets darker and clearer the closer it is to the object.

We all know that the earth is always half a world day and half a world night, and the time close to night is morning and dusk, and generally the light is brightest at noon. The same is true for drawing spheres, half a ball is bright and half a ball is dark, the position where the bright part is perpendicular to the light is the brightest, and the closer to the boundary between light and dark, the darker it will be, and these places close to the dark part are called gray surfaces. The reason why the dark area is not pure black is because it is also affected by reflections and other ambient light sources.

There are three main elements in the formation of light and shade and the careful change of light and shade in the sketch art of sedan chair, one is the existence of light, the second is the structure of the object itself, and the third is the inherent color of the object itself. These three main factors are interrelated, mutually influencing, and mutually restricting, and the changes of each factor directly affect the effect of painting. For example, the amount and timing of the light source, the intensity of the light, the angle, the distance, etc., will directly affect the change of light and shade of the shape.

Secondly, the square and circle of the structure, the simplicity and complexity, the strength and weakness of the wide rubber surface and the undulations, also affect the change of light and dark tones. At the same time, factors such as the color depth and transparency of the shape itself, and the reflective performance also have an impact on the change of light and shade. Among them, the presence of light is the first element and prerequisite, the change of light and shade of the object is governed by the movement of light, the stronger the light, the stronger the light and shade of the object, and the clearer the object we see.

Conversely, the weaker the light, the weaker the contrast between light and dark, the more blurry the object is seen, the contrast between light and dark is not significant, and the farther away this phenomenon is, the more significant it is. For example, the dark side of the cube is closer to the brightest side, the darker it is, and it is because the contrast between light and dark here is the greatest that it appears darker and brighter. The texture also has a certain effect on the brightness and darkness of the object, and the coarser texture of the material is darker.

Conversely, materials with a finer texture and a smooth surface are brighter.

Structural sketches, also known as "body sketches". This kind of sketch is characterized by using lines as the main means of expression, without light and shade, without light and shadow changes, and emphasizing the structural characteristics of the prominent objects.

There are three differences between the two:

1. The concept is different.

The most basic difference between structural sketching and light and shadow sketching is that structural sketching does not have so much light and shade, but only slightly brings the boundary line between light and dark and projection, mainly relying on the weight of the line to reflect the sense of volume and space of the object.

2. Different means of expression.

The characteristic of structural sketching is that lines are used as the main means of expression, abandoning the depiction of light and shadow changes, and deliberately emphasizing the structural characteristics of the essence of objects. There is no change in light and shadow, or some light and dark relationships can be appropriately interfered to emphasize the structural characteristics of the object.

Light and shadow sketching is a powerful stage of the three-dimensional sense and spatial sense of the object through the change of light and shadow on the object, reflecting the rich light and shade levels of the object, and playing an important role in the real representation of the object.

3. The way of expression is different.

Structural sketches are not just outer contours, but also lines that are facing away from us or are invisible. In addition to drawing visible exterior objects, we also draw invisible internal coherent structures and invisible external contours.

Light and shadow sketching is suitable for judging the shape structure of the object under the illumination of the three-dimensional surface, the different textures and chromaticity of the object, the spatial distance of the object, etc., so as to make the picture image more specific and have a strong intuitive effect.