Disegno Tecnico. Capire le Proiezioni Ortogonali, in 6 minuti

Summary

This video explains orthogonal projections, a method for graphically representing three-dimensional objects on a two-dimensional surface. It introduces the concept of projecting an object from three perspectives: top view, front view, and side view. The video details the use of horizontal, vertical, and lateral planes, and how they interact with the object’s placement to generate accurate projections. It also covers the 'flipping plane' (piano di ribaltamento) and how it aids in creating the side view. The viewer learns the significance of distances from these planes to ensure accurate representations of the object’s position.

Takeaways

• 😀 Orthogonal projections are a method for representing 3D objects on 2D surfaces using three distinct views: top, front, and side.
• 😀 The object is projected onto three planes: the horizontal plane (PO), the vertical plane (PV), and the lateral plane (PL), all of which are perpendicular to each other.
• 😀 The horizontal plane (PO) represents the base of the object and is located in the lower-left corner of the drawing.
• 😀 The vertical plane (PV) represents the object's front view and is located in the upper-left corner.
• 😀 The lateral plane (PL) represents the side view of the object and is located in the upper-right corner of the drawing.
• 😀 The line of ground separates the two sets of planes, marking the intersection of the horizontal plane with the other two.
• 😀 The position of the object relative to these planes affects how its projections will appear in the views.
• 😀 Changing the position of the object relative to the planes results in different orthogonal projections, altering the representation of the object.
• 😀 The plane of rotation (piano di ribaltamento) is used to transfer projection lines from one plane to another, particularly useful for obtaining the side view.
• 😀 The method of ribaltamento (rotation) involves projecting points from the horizontal plane to the lateral plane using a compass for accuracy.
• 😀 Understanding distances from the planes (e.g., 2 cm from the vertical plane and 3 cm from the lateral plane) is essential for accurate projection placement on the drawing.

Q & A

What are orthogonal projections and how are they used?

Orthogonal projections are a graphical method for representing objects, including three-dimensional ones, on a two-dimensional sheet. They are obtained by representing the object from three different viewpoints: top view, front view, and side view.

What are the three planes used in orthogonal projections?

The three planes used in orthogonal projections are the horizontal plane (Po), the vertical plane (PV), and the lateral plane (PL). These planes are perpendicular to each other and help in representing the object from different angles.

How is the horizontal plane represented in orthogonal projections?

The horizontal plane (Po) is located at the bottom left of the sheet and represents the base of the object in the projection.

What does the vertical plane (PV) represent in orthogonal projections?

The vertical plane (PV) is positioned at the top left of the sheet and is behind the object in the projection. It helps in showing the object's front view.

What role does the lateral plane (PL) play in orthogonal projections?

The lateral plane (PL), located at the top right of the sheet, represents the side view of the object in the projection.

What is the 'line of the ground' in orthogonal projections?

The 'line of the ground' is the intersection line between the horizontal plane and the other two planes (vertical and lateral), separating the two upper planes from the two lower planes in the projection diagram.

How are orthogonal projections affected by the position of the object?

The position of the object relative to the three planes (horizontal, vertical, and lateral) influences how it is represented in the orthogonal projections. Changing the object's orientation results in different projections.

What is meant by the 'flipping plane' in orthogonal projections?

The 'flipping plane' refers to a method of projection used to transfer points from the horizontal plane to the lateral plane. This process involves using a compass to perform the projection shift from one side of the sheet to the other.

Why are the three views (top, front, side) connected by projection lines?

The three views (top, front, and side) are connected by projection lines to ensure that the representation of the object remains consistent across all planes. These lines help to align corresponding points between the different views.

How are distances from the planes determined in orthogonal projections?

Distances from the planes are calculated by projecting the object's points and lines onto the respective planes. For instance, if an object is 2 cm away from the vertical plane (PV) and 3 cm from the lateral plane (PL), these distances are represented in the projection as segments on the corresponding planes.