Constructing shadows in perspective. Classification of lighting sources

WITH CENTRAL LIGHTING (Fig. 18)

Construct the interior and shadows in perspective according to Fig. 18 (the task is common to all students).

Explanations:

The light source is usually designated by point S*, in our case it is a pendant lamp that is attached to the ceiling at point S*. The construction of shadows is best considered using the example of a single point.

Construct a falling shadow from a certain point A of space onto the object plane H. We enclose parallel segments S*S and Aa in an auxiliary plane R and in this plane draw a light ray from the light source S* through point A until it intersects with the object trace Rh at point A* ≡M. The object trace of this ray at point A* will be the falling shadow from point A onto the object plane H. Therefore, the falling shadow of point A onto the object plane H is the object trace of the light ray emanating from the light source S* and passing through a given point A in space.

The construction of a falling shadow is no fundamentally different from a rectangular plate. The solution is presented in graphical form in Fig. 12.

In the proposed interior there is a case of constructing a falling shadow from the inclined plane of the picture onto a vertical wall. Then the construction is carried out in the sequence as in Fig. 12. The light plane S* AB should be drawn through the point S* and the segment AB; obviously, the shadow from the plane will be its continuation. The object trace AB=M1M2 of the shadow plane AA*B is the falling shadow of the segment AB on the object plane.

Directions for work:

1. construct a perspective of the interior and the objects located on it, the dimensions of which are taken arbitrarily, but taking into account the composition of the sheet.

2. When constructing a falling shadow from a hanging picture, conditionally take the plane of the vertical wall as the object plane and, accordingly, Fig. 12, make constructions.

3. Determine your own shadows of objects.

4. Construct falling shadows on the horizontal plane of the floor and vertical planes of the walls.

5. Color solution produce the interior yourself in compliance with the laws aerial perspective and color science.

EPUR 2

Topic: CONSTRUCTION OF PERSPECTIVE OF SHADOWS FROM ARCHITECTURAL

OBJECTS IN SUN LIGHT (Fig. 19)

Construct, using the architects' method, the perspective of a building and shadows in sunlight parallel to the picture. Take data from table No. 5 according to your option.

Directions for work:

1. Based on these dimensions, construct two types of object - facade and plan.

2. In the orthogonal drawing, determine the elements of the perspective apparatus: set the point of view S, the main perpendicular of the picture SP and the bases of the picture perpendicular to it kk. Using the vertical and horizontal lines, we determine the vanishing points F1 and F2 of the horizon line hh.

4. Transfer the given elements to the picture and, using the architects’ method, construct a perspective of the building.

5. Identify and construct the building's own and cast shadows.

6. When cleaning the building, make the falling shadows darker than your own.

EPUR 3

Topic: PERSPECTIVE OF REFLECTIONS IN FLAT MIRROR SURFACES (Fig. 20)

The diagram consists of 2 tasks.

1. Based on the data in Table No. 6, construct an angular perspective of the interior and its reflection in a flat vertical mirror.

2. Based on the data in Table No. 7, construct the perspective of reflections in a calm water surface (a flat horizontal mirror).

Explanations:

You need to remember the basic physical laws of light reflection from flat mirror surfaces:

1. The incident beam SK and the reflected beam KE lie in the same plane with the normal AK drawn perpendicular to the reflecting surface of the mirror BB (Fig. 13).

2. Angle of incidence equal to angle reflections α=β.

Figure 13c shows the reflected rays of light AB and A1b. A viewer looking into a mirror perceives with his eye the reflected rays Аb and А1b and will see point S in the mirror BB at the intersection of the reflected rays at point S0, which is called mirror image S points

In Fig. 13 it can be seen that points S and S" are located on the same perpendicular to the reflecting plane and are located at equal distances from the base of the perpendicular to point S, i.e. Ss = S"s. This is the basis for constructing an image in a flat mirror.

Directions for work:

1. Two tasks are performed on one sheet.

2. Place the format vertically. Divide it with a horizontal thin line, taking into account the stamp on the field of the lower drawing.

3. When constructing a reflection in a flat vertical mirror, move the interior itself slightly to the left to preserve the construction lines in the drawing.

4. When constructing reflections in a flat water surface, place the vanishing points F1 and F2 of the main directions of the objects on the drawing field.

5. Cleaning should be carried out taking into account the laws of painting.

Classification of lighting sourcesLighting source
Natural source
lighting (sun, moon)
Artificial source
lighting (lamp, candle, etc.)
Natural light source (sun, moon)
Natural source
lighting is located behind
observer
Natural source
lighting is located
in front of the observer
Natural source
lighting is located in
neutral plane

The natural light source is behind the observer

The natural light source is located behind the observer to the right

Constructing a shadow from an artificial light source (lantern)

Constructing a shadow from an artificial light source in the interior

Shadows in paintings

The natural light source is located in a neutral plane

The natural light source is located to the left of the observer

A natural light source is located in front of the observer

Constructing shadows from the sun located in the neutral plane to the left

Constructing shadows from the sun located behind the observer to the left

Constructing shadows from the sun located behind the observer

Constructing shadows from the sun located in front of the observer

Constructing shadows of a cone from the sun located behind the observer

Constructing falling shadows using the ray section method

Constructing shadows from the sun located to the left in the neutral plane

Constructing shadows from the sun located to the left in front of the observer

Constructing shadows from the sun located to the left of the observer

Constructing sun shadows using the ray section method

Constructing shadows using the ray section method from an artificial lighting source

Constructing shadows from the sun located in the neutral plane to the left

It is known that a falling shadow follows the shape of the object that casts it. But everyone who has tried to draw has probably observed how the shape of the shadow is distorted and does not absolutely accurately follow the contours of the object. So what are the rules by which a falling shadow is constructed and what patterns can be identified here?

Constructing falling shadows

First, let's look at this using the example of a simple geometric body - a cube. The figures below show a diagram of the construction of a falling shadow:

1. The light source is determined.
2. A perpendicular is drawn from the light source to the plane on which the object stands.
3. From the point on the plane where this perpendicular rests we draw rays towards the object.
4. Imaginary rays are drawn from the light source and pass through the edges of the object.
5. We mark with dots the intersection of the rays on the plane and the rays from the light source.
6. We connect these points with a line and get the outline of the falling shadow.

To summarize the above and put it more simply, you need to: firstly, draw lines from the light source in space; secondly, draw lines on the plane from the perpendicular. The intersection of these rays will be the contour of the falling shadow.

In a cube drawing, this construction of shadows is relatively simple. But what if our subject is complex? For example, a vase, a tree, a car? Or even “worse” - a human figure? From my experience I will say that falling shadows from such complex shapes I always draw approximately. And, probably, most artists do the same. However, this approximate drawing is still based on the above principle. In the mind, in the artist’s imagination, the same approximate projection is made, and on its basis the outline of the shadow is drawn. But to do this, you need to know the key principle that I outlined above. In the next picture you can see how I approximately lined up the falling shadow from the vase. Everything is done very roughly, but the principle is respected.

(Approximate shadow projection)

How does the shape of a shadow depend on the position of the light source?

In the following pictures I want to show how the position of the light source affects the shape of the shadow and its direction:

If the lamp (or the sun) is located directly above the object from above, then the falling shadow will either be very short or disappear completely. The more the light source is shifted to the side relative to the subject, the longer the shadow will be. The lamp can be located directly in front of the object or, conversely, behind it. In this case, the falling shadow will either move backward from the viewer or approach it forward. All these “stretching” or “compressing” of the shadows will affect its shape. In the above figure, I drew the shadows of the ball. But if you project a falling shadow from a human figure, then its contour will be distorted in a similar way - sometimes stretched, sometimes shortened. It doesn't matter what object we draw a shadow from. The principle will be the same.

How the saturation of the shadow and the clarity of its contour changes

There is a pattern that the artist must understand well - the further the shadow is cast from the object, the lighter it is. The closer the shadow comes to the object from which it falls, the darker it is. This change in saturation can be stronger or weaker depending on the brightness of the light, the size of the shadow, and the distance of the light source. But in any case, the shadow will not be “dull”. It should “breathe” or be “transparent”, which is achieved by changing the saturation. If we are talking about academic drawing, then shadows in the form of solid dark spots should be avoided. If we are talking about black and white graphics, then, of course, the shadows can be completely black, but this is a conventional image, not a realistic one.

In addition, novice artists should also pay attention to the clarity of the shadow outline. The more focused the light (electric lamp, sunlight on a cloudless day...), the clearer the outline of the falling shadows will be. And, conversely, the more scattered the light (light in cloudy weather when it is cloudy), the more blurred the outline of the shadow will become.

Conclusion

Correctly projecting the shadow, determining how its saturation and clarity of the contour changes - these are the main tasks that the artist needs to keep in mind when he draws shadows. Beginners, at first, will have to gradually implement all this in their drawing. But, each time these tasks will become easier and easier. And with the accumulation of experience, the drawing will be obtained on an intuitive level.

An artificial light source, like any point in perspective, is defined in the picture as the perspective of the luminous point itself and the perspective of the base ( see fig. 9.22).

The light source can be located anywhere relative to the illuminated object. It depends on how the artist wishes to use light in the composition of the painting.

The length of the shadow depends on the height of the luminous point and its distance to the illuminated object. The shadow should not extend beyond the horizon line or ABOUT-ABOUT. If it is above the horizon, it is an imaginary shadow. Therefore, you need to choose the right light source.

If an object is illuminated by several light sources, then the falling shadows overlap one another. The place where two falling shadows overlap is called full shadow . The mismatched parts of the falling shadows are called penumbra . First they build their own shadow, then the penumbra, then the full shadow, but not the black one, since it is illuminated by reflected light.

Example 1. Construct a falling shadow from the vertical for two given light sources ( rice. 9.27).

Solution

1. Determine the boundary of your own shadow. For a given position of the light sources, the edges of the shadow will be the boundary V" K V K And E" K E K, i.e. in its own shadow there will be edges A" K A K B" K B K And A" K A K E" K E K.

2. Construct falling shadows from edges A" K A K B" K B K And A" K A K E" K E K first from the first light source, and then from the second.

3. Determine the boundary of the full shadow and penumbra.

Example 3. Construct your own shadow and a falling shadow from a vertical cylinder. The position of the light source is determined by the perspective and the perspective of the base ( rice. 9.29).

Solution

1. Determine the zone of your own shadow. From point C" K(perspective of the base of the source) draw tangents to the lower base of the cylinder. Generators of the cylinder drawn from the points of tangency 1 TO And 6 K, will limit the area of ​​their own shadow.

2. Let's build a falling shadow. To do this, we divide the arc of the base of the cylinder in the unlit part into an arbitrary number of sections of arbitrary length with dots 2" K, 3" K etc.

3. Let's draw generators through these points and construct shadows from these generators. Line 1 T-2 T-3 T-4 T-5 T-6 T will limit the area of ​​the falling shadow.

Constructing shadows in the interior

When depicting interiors, artificial lighting is most often used. Solar lighting in the interior is used only if there are large light openings (terraces). If the windows are of normal sizes, then the light “bunny” can be neglected.

Rule for constructing shadows

To find a shadow from a point, you need to draw a ray through the light source and the point and find the point of intersection of this ray with the plane on which the shadow falls. To do this, solve the problem of the intersection of a line with a plane. We draw an auxiliary projection plane through the light beam: if the shadow is on the floor, then the plane is horizontally projecting; if on vertical walls, it is frontally projecting.

Example 1. Construct a shadow from vertical lines on the floor and side wall of the room at a given position of the luminous point ( rice. 9.30).

Solution. In this example, it is convenient to draw horizontally projecting ray planes. The horizontal trace of these planes will pass through the perspective of the base of the light source and the perspective of the base of the points A And IN. The point of intersection of the trace of the plane with the light ray gives the shadow of the point A on the floor. This construction is called the sail method.

9.3.4. Constructing shadows from objects on various surfaces
in natural and artificial light

Example 1. Construct a falling shadow from the balcony on a vertical wall in natural light ( rice. 9.32).

Solution

1. Determine the zone of your own shadow. The right side wall of the balcony and Bottom part floor.

2. Construct falling shadows from the contour of our own shadows. To do this from the points B K, G K And L K Let's draw light rays at an angle of 45° and determine the points of intersection of these rays with the vertical wall of the house.

To determine the points of intersection of light rays with a vertical wall, we determine the perspectives of the base of all points of the balcony on the object plane (points A" K, M" K, L" K, E" K, J" K, B" K, G" K).

Through the perspectives of the base of the points B" K, G" K, L" K Let's draw the perspective of the base of the light rays until they intersect with the vertical wall (point 1 And 2 ). From points 1 And 2 Let's restore the perpendiculars until they intersect with the light rays drawn from the points B" K, G" K, L" K. Let's connect the obtained points B" K, G" K, L" K. These will be the shadows from the ribs B K G K, G K L K. Connecting V T With E K, we get the shadow from the edge L K M K.

Example 2. Construct a vertical drop shadow AB to the object plane N and onto the surface of a truncated prism ( rice. 9.33).

Solution. Since the point IN vertical belongs to the object plane, the shadow of the point IN coincides with the point itself IN. Thus, solving the problem comes down to constructing a shadow from a point A.

1. Through the perspective of a point A (A K) and source perspective ( S K) hold the perspective of the light beam. Dot ( A T) – hypothetical location of the shadow from the point A on the object plane, if there were no obstacle in the path of the light rays.

2. Through the perspective of the base of the point A (A" K) and the perspective of the base of the source ( C" K) draw a perspective of the base of the light beam.

3. Construct a line of intersection of the horizontally projecting plane of light rays (plane CAB passing through the vertical AB and light source WITH) with the surface of a truncated prism – line 1 K 1" K 2" K 2 K.

4. Vertical shadow AB will go from the shadow of the point IN onto the object plane (coinciding with the point itself IN), along the perspective of the base of the light beam until it intersects with the surface of the prism (point 1 TO). Next - along the line of intersection of the plane of light rays with the surface of the prism. The boundary point of the shadow ( A T) will be the point of intersection of the line 1 K 1" K 2" K 2 K with light beam perspective.

Bibliography

1. Makarova, M. N. Perspective / M. N. Makarova. – M.: Academic project, 2006.

2. Ivashina, G. G. Perspective / G. G. Ivashina. – St. Petersburg: SPbGHPA, 2005.

3. Solovyov, S. A. Drawing and perspective / S. A. Solovyov. – M.: graduate School, 1967.

4. Kotrubenko, M. E. Collection of problems for the course “Descriptive geometry and technical drawing» / M. E. Kotrubenko, O. K. Leskova, L. N. Karagezyan. – St. Petersburg: IPC SPGUTD, 2006.

Related information.

Lecture 24 Constructing shadows in the interior Position of the light source Constructing shadows of geometric bodies Inverse ray method Ray section method

Constructing shadows in the interior is a rather difficult task. This is explained, firstly, by the presence of various lighting sources - solar, diffused and artificial light and, secondly, under conditions of illumination with artificial light sources, a large number of them, a variety of shapes and locations in modern interior make the task of accurately constructing shadow contours quite difficult.

Three cases of constructing shadow contours Depending on the type of interior lighting sources, three cases of constructing shadow contours are possible: With sunlight penetrating through window openings; With point light sources; In diffuse daylight

Constructing shadows in sunlight Task 4. 2 p. 34: Construct a sunspot from the contour of a rectangular window opening (the thickness of the walls is specified and taken into account during construction) The sun is in front of the viewer

Sequence of construction: 1. Construct a falling shadow from the inner contour of the opening: from vertical edges 1 and 2, shadows fall along the projection of the beam, from horizontal edges 2 -1 - in parallel. 2°

2. We build a falling shadow from the external opening (from vertical edges 4 and 3 - along the projection of the beam; from horizontal edges 4 -3 in parallel. We get overlays of shadow points 5 o and 6 o The shadow from edge 4 -3 (4 o-3 o) is superimposed on the shadow from edge 1 -1 at point 6 o. 2° ° °

3. Using a reverse beam, return point 5 o to the horizontal edge 2 -1 of the window sill. Return (.)6 o to the vertical edge 1 -1 ° ° 2° ° °

4. Edge 4 -3 rests on the right side wall at point 3 - the shadow closes. The shadow on the window sill from edge 4 -4 falls in the direction of the secondary projection of the beam. ° ° 2° Sunny “bunny” ° °

Creating shadows in sunlight sunlight, penetrating through a rectangular window opening, forms a clear and contrasting quadrangle on the floor.

Constructing shadows with a point light source With a point light source, the ray lines are not parallel to each other and do not have vanishing points, they intersect at the “luminous” point of the light source Falling shadows are constructed using the secondary projection of the light beam

Problem 4. 4 p. 36: A vertical plane is given in the picture. It is required to construct a shadow from a plate with a point light source

If we take another light source - S*, then an overlay of falling shadows will occur. S* ° Во ° ° S 1* ° Ао

The final drop shadow is determined by general outline. The shadow at the place of the overlay will be darker S* ° Во ° ° S 1* ° Ао

Problem 4. 5 p. 36: The picture shows a vertical plate and a rod resting on its upper edge. It is required to construct a shadow from a plate and a rod with a point light source

Solution: 1. Let's construct a shadow from an inclined line: Let's draw a light ray through (.)S' and (.)A', and the secondary projection of the ray S' 1 and A' 1 and find their intersection. Ao‘

Since the straight line AC rests on the plane of the floor, the shadow at the point of support in it itself is C'= C 1'= Co' By connecting the points Co' and Ao' we get a shadow from the straight line to the floor

2. At point B, the rod rests on the plate - the shadow closes 3. Construct the shadow of the plate

Problem 4. 6 p. 37: The picture shows the perspective of a prism and a rod resting on its upper edge. It is required to construct a shadow from a prism and a rod with a point light source

2. Determine your own shadows on the prism. Constructing a falling shadow from a prism 2 1 21 11 1 o 2 o

3. To determine the shadow from the inclined straight line AB onto the upper plane of the prism, you can use: a) the reverse ray method: we return the point of overlap of the shadows from the straight AB to the shadow from edge 2 -3 (Mo) to edge 2 -3 3 m mo 1 11 2 21 1 o 2 o

Problem 4. 7 p. 37: the picture shows a triangular prism and a right circular cone. It is required to construct a shadow from them with a point light source

Solution: 1) To construct the shadow of a cone, find the shadow of its vertex (.)T‘ -To‘

2) Determine the falling shadow: draw tangents from (.)To‘ to the base of the cone, then determine our own shadow. 3) Using the ray section method, we determine the shadow from the top of the cone on the inclined plane of the roof

The second option for constructing a shadow from a cone onto a prism: using the inverse ray method (we return points 1 o and 2 o of the shadow overlay from edge B and the cone to edge B’) °° ° °

When constructing shadows in the interior perspective, you should first construct projections of the light source onto those enclosing planes of the interior on which you will need to construct shadows: floor, ceiling, walls

Task 4. 8. p. 38: Construct projections of a point light source onto the vertical planes of the walls and floor in a given frontal perspective of the interior

Solution: 1) We determine the projections of the light bulb S onto the walls, floor and ceiling (through the light source we draw perpendiculars from (.)S to these planes. Since the frontal perspective of the interior is a plane perpendicular to the side walls, floor and ceiling, parallel to the picture) .

Example: Light source L. Vertical straight line Вв is perpendicular to the floor, therefore the shadow falls along the projection of the beam on the floor to the wall and vertically along the wall. °

L 1“ – projection of the light bulb onto the left side wall. With its help, we construct a shadow from the straight line “A.” °

L‘ - projection onto the end wall - since the side walls are perpendicular to the end wall, the shadow from horizontal straight openings falls along the projection of the ray onto the end wall drawn through L‘ Point of contact in the end plane ° ° Point of contact in the end plane

Task 4. 9 p. 38 b): Construct shadows from furniture with a point light source on the frontal perspective of the interior

From the vertical line 1 -11 the shadow falls along the projection of the ray, from the horizontal edge of the step - parallel and closes to the stop point. Point of stop

We determine the projections of the luminous point S on the plane of the steps (S 2, S 3, S 4). To do this, draw a plane parallel to the picture through the light source and determine the height of the steps at a given depth

We determine the lighting of the steps and build our own shadows. The vertical plane of the third stage is located in the same plane with point S (sliding beam). The vertical plane of the fourth stage is illuminated. Using (.) S 2 we build a falling shadow from the vertical edge 2 -21

From straight N-M on the rear end wall the shadow is parallel, then closes at the stop point M≡Mo. We construct a falling shadow from the cabinet using its secondary projection on the floor. Find the shadow from edge 1 -2 (1 o-2 o)

Edge 1 -3 is parallel to the wall, therefore its shadow falls parallel to the wall, i.e. we build using (.)P 4

Horizontal edge 2 -4 is also parallel to the plane of the wall. We build a shadow 2 o-4 o using point P. Next, the shadow closes at the point of contact of the straight line 4 -5 into the wall. Stop point

To construct a shadow from a vertical line A, we determine the projection of the light source onto the podium (Sp) using an arbitrary vertical plane (point F is taken arbitrarily)

The shadow from the straight line on the podium falls in the direction of the beam projection, on the vertical wall - parallel to the straight line

Task 4. 9 p. 39 c): Construct shadows from furniture with a point light source on the frontal perspective of the interior

Determine the shadows from points A and B (Ao 1 on the floor, Bo 2 on the wall)

We determine the break by constructing the shadow from (.)L and the closure of the shadow on the right wall C=Co Point of emphasis

We determine the falling shadows from the columns on the wall and on the ceiling (closed at the point S≡Sp); to construct a shadow on the balcony, we find the projection of the light bulb to the floor level of the balcony Sb ≡Sп ° Sb

To construct the falling shadow from the balcony onto the columns, draw an imaginary tangent plane to the columns and determine the lines of tangency on the columns. Imaginary plane tangent to the columns

Draw a shadow from a horizontal edge passing through (.)A on the imaginary plane using (.)P

At the intersection of this shadow from edge “A” with the tangents on the columns, we fix the points of the actually existing shadow (peak points)

We find the overlay of shadows from the columns and the balcony - points 1 o and 2 o and using the inverse ray method we return them to the contour of the columns’ own shadow - points 1 and 2 ° 2 1 ° ° 1 ° ° 2 o

Task 4. 10 p. 40: Construct projections of the light source onto two vertical planes of the walls, floor and ceiling in the angular perspective of the interior

Angular perspective of the interior. Method of combining the object plane with a picture Solution: Let's consider the first option - the room has a 90° angle in plan. C is the light source on the floor plan. Let us draw straight lines parallel to the walls of the room through (.)C and determine (.)1 and 2 picture traces of these straight lines 1 2

Constructing projections of a light source in a corner interior We construct perspective projections of a light source C using straight lines parallel to the sides of the plan: We construct the perspectives of these straight lines The intersection of perspectives of straight lines gives (.)Sp - projection (.)C on the floor we determine the nearest points 1 and 2 in the picture on ceiling

Constructing projections of a light source in a corner interior Constructing straight line perspectives The intersection of straight line perspectives gives (.)Sp - projection (.)C on the ceiling At an arbitrary distance we “hang” the light source C Sp ° ° C

Constructing projections of a light source in a corner interior To construct a projection (.)C onto wall P 2, you need to draw a perpendicular to it. Since the angle between the walls in plan = 90°, the perspective of a straight line perpendicular to the wall is constructed using (.) F 1 we determine (.) C 2

Constructing projections of a light source in a corner interior We similarly determine the projection of a light bulb on the right side wall C 3 (using (.) F 2.) ° C 3

Var. 2: Constructing projections of a light source if the angle between the walls on the floor plan is α≠ 90°. Perspective projection (.) C can be constructed using straight lines parallel to the walls of the room, i.e. using vanishing points F 1 and F 2 To determine projections draw the light source through (.)C straight lines m and n, perpendicular to the walls of the room

Construction of projections of a light source at an angle between the walls α≠ 90° on the floor plan. Let us determine the vanishing points of straight lines m and n, for which, through the combined point of view with the picture (.)S', we will draw straight lines parallel to m and n and find their intersection with the horizon line ( Fm and Fn respectively)

Construction of projections of a light source at an angle between the walls α≠ 90° on the floor plan. Using the vanishing point Fm, we find the projection C of 2 points C on the side plane

Construction of projections of a light source at an angle between the walls α≠ 90° on the floor plan. Similarly, we determine the projection C 3 of point C on the right side plane using point Fn

Construction of projections of a light source at an angle between the walls α≠ 90° on the floor plan. planes were constructed passing through the light source (.)C and perpendicular to the side walls to determine the projections of the lamp onto the side walls

Task 4. 11 p. 41: Construct shadows from a point light source in a given angular perspective of the interior

Solution: 1. The internal partition in the closet is in its own Shadow. We build a falling shadow from it using a projection on the floor

We determine the shadows from points 1, 2, 3. From (.)1 hit the wall, from (.)2 and 3 to the shelves
Constructing shadows with diffused lighting With diffuse, diffused light penetrating through a window opening, light is emitted over the entire area of ​​the opening. The contours of the shadows seem to overlap one another, their boundaries becoming more and more “blurred” as they move away from the light opening. The planes of the slopes are illuminated, therefore the vertical and horizontal edges of the slopes of the opening, facing the inside of the room, are shadow-forming.

Construction of shadows in diffused lighting From the many “luminous” points in the opening, points located in the corners of the opening (1, 2, 4, 5) are distinguished. Using points 1, 2 and 3, cast shadows on the floor, and using points 4 and 5 - on the ceiling. To construct shadows, it is necessary to project these points onto those planes of the room on which the shadows should be constructed: on the floor (points 1, 2), on the ceiling (points 4 and 5) and on the side wall (5"). Then draw from the “luminous” perspective points of ray lines through the shadow-forming points of the object until they intersect with the secondary projections of these rays

Constructing shadows with diffused lighting For example, let’s take “luminous” point 1, located in the upper corner of the opening. To construct a shadow from (.)A, it is necessary to draw a light ray through it and find its intersection with the projection of the ray on the floor. 1°° 11

Then we build shadows from AB and from BC ° 1 ° ° 11 Co ° Ao Vo

Let's take “luminous” point 2, located in the upper left corner of the opening. Let's construct shadows from points C and D and determine the shadow from straight line CD on the right wall. Let's complete the construction of the shadow from BC 2 ° Point of emphasis ° Co ° ° Ao Vo

Edge G of the inner part of the opening partially blocks the flow of light. Let's find the “luminous” point 3, located on the upper edge of the opening. To do this, we connect the projection of the vertical edge G (G 1) with the projection (.) A and extend it until it intersects with the projection outside opening – (.)3¯ Ж ° С ° Ж 1 ° Ао Вo

Let's construct shadows from the vertical edge of the table leg E using the “luminous” point 3. We complete the construction of the shadow from the horizontal edge of the table passing through point E ° Point of emphasis in the lateral plane ° ° ° Ao Vo Co

Let's construct shadows from the horizontal edge of the LG opening using the “luminous” point 5 on the ceiling. g g ° Point of emphasis in the lateral plane of the wall ° ° С ° Ао Вo

Let's construct a shadow from the vertical edge GG 4 of the opening using the “luminous” point 4. On the ceiling the shadow falls along the projection of the beam, on the wall parallel to edge G). 44 ° G 4 f g ° Point of emphasis in the lateral plane of the wall 4 ° Co ° Ao Vo

Let's construct a shadow from the horizontal edge of the opening using the “luminous” point 1. The shadow falls on the floor parallel to the edge). f g ° ° ° Co ° ° ° Ao Bo ° °