Files
orx/orx-camera
2025-10-14 13:30:41 +00:00
..
2025-10-14 13:30:41 +00:00

orx-camera

2D and 3D cameras controllable via mouse and keyboard.

Usage

import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.draw.DrawPrimitive
import org.openrndr.extra.camera.AxisHelper
import org.openrndr.extra.camera.GridHelper
import org.openrndr.extra.camera.OrbitalCamera
import org.openrndr.extra.camera.OrbitalControls
import org.openrndr.extra.meshgenerators.boxMesh
import org.openrndr.extra.meshgenerators.sphereMesh
import org.openrndr.math.Vector3

fun main() = application {
    program {
        val camera = OrbitalCamera(
            Vector3.UNIT_Z * 90.0, Vector3.ZERO, 90.0, 0.1, 5000.0
        )
        val controls = OrbitalControls(camera, keySpeed = 10.0)

        val sphere = sphereMesh(radius = 25.0)
        val cube = boxMesh(20.0, 20.0, 5.0, 5, 5, 2)

        extend(camera)
        extend(AxisHelper()) // shows XYZ axes as RGB lines
        extend(GridHelper(100)) // debug ground plane
        extend(controls) // adds both mouse and keyboard bindings
        extend {
            drawer.vertexBuffer(sphere, DrawPrimitive.LINE_LOOP)
            drawer.vertexBuffer(cube, DrawPrimitive.LINE_LOOP)
            drawer.stroke = ColorRGBa.WHITE
            drawer.fill = null
            repeat(10) {
                drawer.translate(0.0, 0.0, 10.0)
                // 2D primitives are not optimized for 3D and can
                // occlude each other
                drawer.circle(0.0, 0.0, 50.0)
            }
        }
    }
}

Keybindings

  • w - move forwards (+z)
  • s - move backwards (-z)
  • Left or a - strafe left (-x)
  • Right or d - strafe right (+x)
  • Up or e - move up (+y)
  • Down or q - move up (-y)
  • Page Up - zoom in
  • Page Down - zoom out

Demos

DemoCamera2D01

Camera2D demo

click and drag the mouse for panning, use the mouse wheel for zooming

DemoCamera2D01Kt

source code

DemoCamera2D02

Camera2D demo with static elements

An approach for having certain elements not affected by the camera. See DemoCamera2DManual01.kt for a new and simpler approach

DemoCamera2D02Kt

source code

DemoCamera2DManual01

Demonstrates how to use Camera2DManual to have some elements affected by an interactive 2D camera combined with other elements not affected by it.

In this example both PINK circles can be dragged, scaled and rotated while the white circle in the middle is static.

DemoCamera2DManual01Kt

source code

DemoCamera2DManual02

Demonstrate the use of Camera2DManual to independently translate, scale and rotate one contour in a collection.

When the mouse is clicked, the active contour is transformed using the camera view matrix, then the camera is reset to its default state and whatever shape is under the mouse becomes the new active contour.

As the mouse is dragged or its wheel scrolled, the camera is updated, affecting how the active contour is rendered.

DemoCamera2DManual02Kt

source code

DemoOrbital01

Demonstrate the use of Orbital, an interactive 3D camera that can be controlled with a mouse and a keyboard.

DemoOrbital01Kt

source code

DemoOrbitalCamera01

Demonstrate the use of OrbitalCamera, OrbitalControls, AxisHelper and GridHelper.

Press the t key to toggle camera interaction, or r to reset the camera to its defaults.

DemoOrbitalCamera01Kt

source code

DemoOrbitalManual01

Demonstrate the use of an orbital camera to render a sphere and a cube in 3D space as wireframe meshes, positioned and rendered independently using the camera's isolated drawing state. A stationary pink circle is also drawn in the center of the scene.

Functionality:

  • Initializes a sphere mesh and a cube mesh with predefined dimensions.
  • Spawns an orbital camera, initially positioned away from the origin, to allow for focused rendering.
  • Renders 3D wireframe shapes (sphere and cube) using the camera's isolated perspective.
  • Draws a static 2D pink circle overlay at the window center.

DemoOrbitalManual01Kt

source code

DemoParametricOrbital01

Demonstrates the use of a ParametricOrbital camera. This 3D camera can't be directly interacted with a mouse or a keyboard, but only via a GUI (or via code).

The GUI state is saved when closing the program and loaded when running it again.

The GUI also allows randomizing, loading and saving its state to a file via the top buttons it displays.

DemoParametricOrbital01Kt

source code