Range (max = min + range). Isolate specific bounces!
🚀 Auto-focus & Visualization
The default aperture is small, keeping most of the scene in focus.
Lower the F-stop to introduce depth-of-field blur and reduce the in-focus range.
Click any object in the scene to trigger autofocus.
Green = traditional planar focus, Red = Scheimpflug (tilt-shift). Tolerance = pixels of acceptable blur.
☁️ Volume (Particilating Media)
Required for environment fog and volumetric spheres. Only preliminary volumetric support is included, due to the high computational cost of real-time volumetric path tracing.
Each colored dot on the right is the object-side focus of the same-colored image sample on the left, shown at a separate scale. They are neither scene lights nor a blur image. A smaller F-number widens the pupil and defocus cone; it does not move ideal focus. Camera rays follow the selected planar focus (including the three-point tilt gizmo); the image points are equivalent thin-lens conjugates. Thin-lens lesson instead traces from the physical sensor controls: the center ray remains straight, and a ray parallel to the lens axis passes through its focal point. Pupil shows a normalized front-view shape guide, with the current f/N diameter below it; it does not show the sampling density. The sensor icon gives nominal dimensions, and its curvature stroke is decorative: the lesson uses a flat sensor. These rules use an ideal paraxial lens, not an aberrated compound lens. Legacy film-tilt blur, distortion and chromatic effects are not reconstructed here. Thin-lens model · Tilt-shift geometry (chapter 31).
Based on Ray Tracing Gems II - Tilt-Shift Rendering Using a Thin Lens Model
Three-point focus-plane model inspired by RTG II Ch.31. The diagram follows the gizmo and derives a tilted pupil. Near-parallel view rays can have no finite forward intersection; this experimental renderer uses a bounded fallback there, rather than modeling a real lens system.
Shows: RGB spheres, axes, and focal plane triangle. Hover to highlight, click and drag to manipulate.
How it works:
• The gizmo (triangle) defines the focal plane in 3D space.
• Hold on RGB spheres to rotate the focal plane.
• Hold LMB on the center of the triangle to translate it in XY-plane (parallel to the image plane);
• Hold RMB on the center of the triangle to translate it in XZ-plane (perpendicular to the image plane);
• First increase the aperture size (smaller F-stop), then play with the gizmo and see how the depth of field changes in action.
• Near a parallel ray/plane configuration, focus can move arbitrarily far or behind the camera. Treat the fallback as a limitation of this model.
🌈 CHROMATIC ABERRATION & EFFECTS ⭐
Wavelength-dependent IOR creates rainbow dispersion through glass.