RadianceKit User Guide

What is RadianceKit?

RadianceKit turns photos or videos of real-world objects into interactive 3D models using Gaussian Splatting — a modern technique that represents scenes as millions of tiny, colored 3D ellipsoids (called Gaussians) rather than traditional triangle meshes.

The result is a photorealistic 3D reconstruction you can view from any angle and export in various formats.


Quick Start

  • Import — Drop photos or a video of your scene into the app
  • Process — RadianceKit aligns your cameras and trains a Gaussian Splatting model
  • Preview — Explore the 3D result in the interactive viewport
  • Export — Save as PLY, SPZ, glTF, or other formats
That's it. In Simple Mode, the entire workflow is a single button click after importing.

Importing Media

Photos

For best results:

  • Use 10–50 images taken around the object from different angles
  • Overlap between consecutive images should be at least 60%
  • Avoid motion blur and overexposed areas
  • Consistent lighting produces the best results
  • Supported formats: JPG, PNG, HEIC, TIFF
You can drag & drop images, use File > Browse Files, or drop an entire folder.

Video

Drop a video file (MP4, MOV) and RadianceKit will automatically extract frames. Adjust the sampling density to control how many frames are extracted per second of video.

  • Higher density = more images = better quality, but longer processing
  • A 10-second video at 2 fps density yields ~20 frames

Existing Scenes

You can also open previously exported scene files:

  • .radiancescene — RadianceKit's native scene bundle (includes Gaussians + camera data)
  • .ply / .spz / .splat — Gaussian Splatting files from other tools

Processing Pipeline

Camera Alignment (Structure from Motion)

RadianceKit first determines where each photo was taken from. This step, called Structure from Motion (SfM), analyzes visual features across your images to compute camera positions and orientations.

Two backends are available:

  • Apple Photogrammetry — Built-in, no installation needed. Works well for most scenes.
  • COLMAP — External tool, better for large outdoor scenes. Requires separate installation.

Gaussian Splatting Training

Once cameras are aligned, training begins. The algorithm:

  • Places initial Gaussians at detected 3D points
  • Iteratively refines their positions, colors, sizes, and orientations
  • Periodically adds and removes Gaussians (densification) to capture detail
You can watch the 3D model improve in real time in the viewport.

#### Training Presets

PresetIterationsUse Case
Quick1,000Fast test, low quality
Preview5,000Quick preview
Balanced20,000Good quality, reasonable time
Quality40,000Best quality
Two densification strategies are available:
  • Classic — Original clone/split/prune approach. Faster, produces more Gaussians.
  • MCMC — Stochastic Gradient Langevin Dynamics (NeurIPS 2024). Fewer Gaussians, slower, but more compact results.

The Viewport

Navigation

InputAction
Mouse DragOrbit around the scene
Shift+Drag or Right-DragPan the camera
Scroll WheelZoom in/out
Double-clickRe-center on a point
Cmd+ScrollAdjust field of view

Fly-Through Mode

Press F to switch between Orbit and Fly-Through mode. In Fly-Through:

  • WASD — Move forward/back/left/right
  • Q / E — Move up/down
  • Mouse controls look direction

Camera Views

  • 0–9 — Jump to training camera positions (1 = first 10%, 0 = last)
  • Left/Right Arrow — Step through training cameras
  • R — Reset camera to default position
  • T — Toggle auto-rotation (turntable)
  • B — Cycle background color (dark gray / black / white)

Capturing

  • S — Save a screenshot to the Desktop
  • V — Record a 360° turntable video
  • C — Copy camera position info to clipboard

Editing

Press Tab or use Viewport > Enter Edit Mode to activate the Gaussian editor.

  • Click / Drag — Paint-select Gaussians with a brush
  • Option+Click — Deselect Gaussians
  • [ / ] — Decrease / increase brush size
  • X or Delete — Delete selected Gaussians
  • Cmd+Z — Undo last deletion
  • Esc — Clear selection
This is useful for removing floating artifacts or unwanted parts of the scene.

Exporting

RadianceKit supports multiple export formats:

3D Formats

FormatExtensionDescription
PLY.plyStandard point cloud format. Widely supported.
Compressed PLY.plyQuantized attributes for smaller file size.
SPZ.spzGoogle's compact Gaussian format. Very small files.
glTF.glbWeb-ready 3D format. Works with three.js and other viewers.
.splat.splatLightweight format for web viewers.
SOG.sogCompact sorted Gaussian format.

Media

FormatDescription
Orbit Video360° turntable video (MP4)
Web ViewerSelf-contained HTML file with interactive 3D viewer

Post-Processing

Compactification can be enabled in the Enhancements section. It removes nearly-invisible Gaussians after training, reducing file size by ~55% with no visual quality loss.


Expert Mode

Switch to Expert Mode via Mode > Expert Mode (Cmd+2) for full control:

  • Navigator (left sidebar) — Browse imported images, camera list, and log
  • Inspector (right sidebar) — Training presets, configuration, live metrics, loss chart, enhancements, and export
  • Viewport — Full interactive 3D view with all controls
  • Drag inspector sections to reorder them; collapse sections you don't need

Tips for Best Results

  • Overlap is key — Ensure at least 60% overlap between consecutive images
  • Move around the object — Cover all sides, including top if possible
  • Consistent lighting — Avoid mixed lighting or strong shadows that change between shots
  • Steady shots — Avoid motion blur; tripod or stable handheld
  • Neutral background — Simple backgrounds help the algorithm focus on the object
  • More images help — 30–50 images usually produce excellent results
  • Use Balanced or Quality presets — Quick/Preview are for testing; final results need more iterations
  • Try MCMC for compact exports — If file size matters, MCMC produces ~70% fewer Gaussians

Keyboard Shortcuts Reference

Navigation

KeyAction
Mouse DragOrbit / Look around
Shift+Drag / Right-DragPan camera
ScrollZoom / Move forward
WASDMove camera
Q / EMove up / down
FToggle Orbit / Fly-Through
Double-clickRe-center on point
Cmd+ScrollAdjust field of view

Views

KeyAction
RReset camera
TToggle auto-rotation
PToggle camera playback
BCycle background
0–9Jump to training camera
Left/Right ArrowPrevious/next camera

Capture

KeyAction
SSave screenshot
VRecord turntable video
CCopy camera info

Editor

KeyAction
TabToggle edit mode
Click / DragSelect Gaussians
Option+ClickDeselect
X / DeleteDelete selected
Cmd+ZUndo
[ / ]Brush size
EscClear selection

Other

KeyAction
Cmd+1Simple Mode
Cmd+2Expert Mode
Cmd+OOpen Scene
Cmd+SSave Scene
Cmd+Shift+SSave Screenshot
Cmd+Shift+TStart Training
Cmd+?Keyboard Shortcuts
HToggle help overlay