PROYEKSI PIKTORIAL

Summary

This video lesson discusses projection techniques, focusing on two main types: pictorial and orthogonal projections. Pictorial projection is divided into perspective, oblique, and axonometric types (isometric, dimetric, and trimetric). The video explains how objects are represented on paper with different scaling ratios based on angles and axes. It further touches on the concept of foreshortening and how to apply it when drawing in various projections. Orthogonal projection types (European and American) are introduced, but further details will be covered in the next session.

Takeaways

• 😀 Understanding projections: How to present a real object in a drawing.
• 📏 Types of projection: Divided into pictorial and orthogonal projections.
• 🖼️ Pictorial projection: Further divided into perspective, oblique, and axonometric projections.
• 🎨 Axonometric projection: Includes isometric, dimetric, and trimetric methods.
• 🌍 Orthogonal projection: Split into European and American methods.
• 🔍 Isometric projection: Uses a 30-degree angle, and the reduction scale is 1:1:1.
• 📐 Dimetric projection: Uses a 35-degree angle, with reduction scales of 1:3/4:1 for the X, Y, and Z axes.
• 🎛️ Trimetric projection: Involves different angles for X and Y axes, with unique reduction scales.
• 🌀 Oblique projection: Objects are angled, with reduction scales based on the tilt angle (e.g., 30, 45, 60 degrees).
• 👁️‍🗨️ Perspective projection: Divided into one, two, and three-point perspectives, each representing different vantage points.

Q & A

What is the definition of projection in the context of this lesson?

Projection is the method of representing a real object in a drawing, showing how an object is presented on paper.

What are the two main types of projections mentioned in the script?

The two main types of projections are pictorial projection and orthogonal projection.

What are the three types of pictorial projections?

The three types of pictorial projections are perspective projection, oblique projection, and axonometric projection.

What is axonometric projection and how is it divided?

Axonometric projection shows the edges of an object tilted relative to the projection plane, making three surfaces visible. It is divided into isometric, dimetric, and trimetric projections.

What are the differences between isometric, dimetric, and trimetric projections?

In isometric projection, the angles between the axes are 30 degrees, and the scale reduction is 1:1:1. In dimetric projection, the angles are 35 degrees, and the scale reduction is different for each axis (1:1 for X and Z, and 3/4 for Y). In trimetric projection, the angles and scale reductions vary for all three axes.

What is the purpose of scale reduction in projections?

Scale reduction is used to proportionally reduce the dimensions of the object along specific axes to accurately represent it in the projection.

How is scale reduction applied in dimetric projection?

In dimetric projection, for an object with a length of 100 mm along the Y-axis, the length will be scaled by 3/4, resulting in a 75 mm representation on the Y-axis, while the X and Z axes retain their original dimensions.

What is oblique projection and how is it different from orthogonal projection?

Oblique projection occurs when the projection is not perpendicular to the projection plane, resulting in a tilted view. Orthogonal projection involves projecting the object perpendicularly to the projection plane.

What is perspective projection and how is it categorized?

Perspective projection focuses all projection lines toward one or more vanishing points, creating a realistic sense of depth. It is categorized into one-point, two-point, and three-point perspective, depending on how many vanishing points are used.

What will be covered in the next lesson according to the speaker?

The next lesson will focus on orthogonal projection, as the current session only covered axonometric projection.