Camera Frustum
Thu, 05 Oct 2023 12:58:09 GMT — Properties
Properties
| Key | Value |
|---|---|
| Identifier | camera-frustum |
| Name | Camera Frustum |
| Type | Topic |
| Creation timestamp | Thu, 05 Oct 2023 12:58:09 GMT |
| Modification timestamp | Thu, 05 Oct 2023 12:58:09 GMT |
In the context of computer graphics and three.js, the camera frustum represents the viewable portion of the 3D scene. It is a geometric shape that resembles a pyramid with its top chopped off. The frustum defines what can be seen (the viewable area) from a particular camera position and orientation.
Here are the key components of the camera frustum in three.js:
- Near Plane: The near plane is the closest clipping plane of the frustum. Objects nearer to the camera than this plane are not rendered. This prevents rendering objects that are too close to the camera, which can cause visual artifacts.
- Far Plane: The far plane is the farthest clipping plane of the frustum. Objects farther away from the camera than this plane are not rendered. This prevents rendering objects that are too far away, which can also cause visual artifacts. Adjusting the distance between the near and far planes is crucial for managing the depth precision of the scene.
- Field of View (FoV): The field of view is the angular extent of the scene that is visible from the camera. It is usually specified in degrees and defines how wide the frustum is at the near plane. A larger FOV value results in a wider view, while a smaller FOV value results in a narrower, more zoomed-in view.
- Aspect Ratio: The aspect ratio is the ratio of the frustum's width to its height. It is typically derived from the width and height of the viewport or the screen. Maintaining the correct aspect ratio is essential for preventing distortion in the rendered scene.
- Projection Matrix: The camera frustum parameters (near plane, far plane, FOV, and aspect ratio) are used to calculate the projection matrix. This matrix transforms 3D coordinates into 2D coordinates on the screen, accounting for perspective effects.
In three.js, the camera frustum is set when you create a camera object, such as PerspectiveCamera or OrthographicCamera. You specify the near and far planes, field of view, aspect ratio, and other properties during the camera initialization. The camera frustum determines what objects are visible from the camera's viewpoint and how they are projected onto the screen.
Managing the camera frustum correctly is essential for creating visually accurate and efficient 3D scenes. It ensures that objects within the frustum are rendered, while those outside it are culled, optimizing the rendering process and improving performance.