Deconstructing Reality Composer Pro (Viewport)
Viewport is deep (modes, debug views, presets/history). We are going to implement just a working viewer + camera for this pass; chasing full parity will balloon scope.
The main viewport is built with RealityKit, and we'll add a layer for gestures, a grid, and a simple Arcball implementation to allow navigation. Also, given we have access to camera history in the .rcuserdata metadata, implementing this function is easy, though I don't use it much myself.
Scene Lighting
Reality Composer Pro also provides environment lighting through a popover panel accessible from the floating toolbar. The panel exposes:
- Environment presets—HDR panoramas that provide both lighting (IBL) and optional skybox background
- Rotation—spins the environment around Y-axis (0-360°)
- Exposure—adjusts light intensity in EV stops (-3 to +3)
- Background toggle—this feature allows you to display the environment as a skybox or as a solid color.
Each one of these features is essential for art direction, so we will add them using ImageBasedLightComponent.
Release 3-viewport · elkraneo/Deconstructed
Viewport menu + framing, grid toggle, camera history
elkraneo
RealityKit Outline Selection
TLDR: MeshResource.contents, three passes, one PostProcessEffect 1. Rasterize the selected mesh into an offscreen R8Unorm silhouette mask 2. Dilate the mask into a pixel-wide edge ring, suppressing the interior 3. Composite the outline color over the source frame One of the most commonly requested affordances when dealing with 3d
Cristian Díaz
