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Relief3D Guide
Relief 3D turns a flat 2D fractal into terrain. It reads the fractal's own data (how fast each point escapes, how many iterations it took, how dense the orbit is) as a height field, then lights that height as raised relief — or renders it as a full 3D landscape you can orbit, fog, and export as a printable mesh.
Two modes, from cheapest to richest:
- Screen-space relief — embosses the flat image and drapes horizon cast shadows over it. Fast, keeps the exact framing of the 2D view.
- Oblique 3D raymarch — a true 3D render of the height field from a tilted camera: real perspective, a silhouette against the sky, volumetric fog and god-rays, and mesh export.
For ready-made settings, see the companion Relief 3D Cookbook.
Companion pages: User Index · Relief 3D Cookbook · Volumetric Lighting Guide · Heightfield Relief Spike (Technical)
Note
Fastest path to a 3D-looking fractal: open Relief 3D, tick Enable raised relief + cast shadows, and lower the Light elevation to ~25° for long dramatic shadows. That's screen-space relief. For a true orbitable landscape, also tick Oblique 3D raymarch.
Relief 3D has its own standalone panel:
- Control Center → Color & Light → "Relief 3D…" — opens the panel. It's independent of Fractal Params and stays open when you close Params.
- Fractal Params → "Open Relief 3D…" — the same panel, shown whenever the current fractal supports relief.
The panel shares the Lighting & FX dialog (soft shadows, AO, PBR, IBL/HDRI, reflections, volumetric fog). Its "Open Lighting & FX…" button opens it without leaving Relief 3D.
Relief 3D applies to 2D fractal families, each with a natural height source:
| Family | Height comes from |
|---|---|
| Mandelbrot, Julia, Multibrot, Phoenix, Glynn, Spider, Burning Ship, Tricorn, Magnet 1 & 2, and the generated Mandelbrot Z²–Z⁵ / Tricorn / Burning Ship variants | Escape potential (smooth iteration count) |
| Newton, Nova, Halley (root-finding) | Iteration count to convergence |
| Buddhabrot family | Orbit density |
| Apollonian gasket | Synthesised dome (sphere-cap height per disc) |
3D ray-marched fractals (Mandelbulb, Mandelbox, Quaternion, Kleinian, …) are already 3D and don't use Relief 3D — they have their own camera and lighting.
The fractal's per-pixel value becomes a height h(x, y). A height curve
shapes it first (see below), and a height scale exaggerates it. From there:
- Screen-space relief shades that height with a single light and marches along the light direction across the height field to drop cast shadows — all in the plane of the flat image. The result is blended over the themed color by Relief strength.
- Oblique 3D raymarch builds an actual 3D surface from the height field and sphere-traces it from a tilted camera. This gives true perspective, a silhouette edge, and access to the full shading pipeline (shadows, AO, PBR, IBL, and volumetric fog / god-rays — see §6).
Raw fractal boundary data spikes hard — the escape count shoots up right at the set edge. The Height curve tames that into terrain:
| Curve | Effect |
|---|---|
| Log (default) | Compresses the spikes into rolling terrain. Best general choice. |
| Sqrt | Gentler compression — more relief than Log, less spike than Linear. |
| Linear | Raw, un-tamed height. Spiky needles at the boundary; use for sci-fi/crystal looks. |
Enabled by "Enable raised relief + cast shadows." Fast; keeps the 2D framing.
| Control | Range | Default | What it does |
|---|---|---|---|
| Height scale | 0 – 6 | — | Vertical exaggeration. Higher = deeper carving and longer shadows. |
| Light azimuth | 0 – 360° | — | Compass direction of the light. 0 = from the right, 90 = from the top. |
| Light elevation | 1 – 89° | — | Light height above the plane. Lower = longer, more dramatic cast shadows. |
| Shadow strength | 0 – 1 | — | How dark cast shadows go. 0 = no shadows; 1 = fully black. |
| Relief strength | 0 – 1 | — | Blend between relief lighting and the flat themed color. 1 = full relief. |
Note
Screen-space relief reads best on smooth, non-noisy themes and when you're zoomed into filament structure. Busy rainbow palettes fight the shading.
Enabled by "Oblique 3D raymarch (perspective + volumetric)." Heavier than screen-space relief, but a true 3D scene.
| Control | Range | What it does |
|---|---|---|
| Camera azimuth | −180 – 180° | Orbit the terrain around the up axis. 0 = straight on. |
| Camera elevation | 5 – 89° | Camera height. 90° ≈ top-down (looks flat); low = raking, dramatic silhouette. |
| Camera FOV | 15 – 100° | Vertical field of view. Wider = more perspective distortion. |
| Frame-fill zoom | 0.2 – 5 | How much of the window the terrain fills. 1.0 = auto-fit; >1 pulls in (edges may clip); <1 pulls back for margin. |
| Anti-alias (N×N) | 1 – 4 | Supersampling: N×N rays/pixel averaged. 1 = fastest; 2–4 = smoother edges/silhouette at N² cost. |
| Height curve | Log / Sqrt / Linear | Tone curve on the height field (see §2). |
| Edge fade | 0 – 0.5 | Ramps the height to the base plane near the image edges, so structure running off-frame tapers out instead of forming streaky "arms". 0 = off. |
| Field floor (px) | 480 – 2160 | Short-axis resolution the height field is computed at, independent of window size. Only active with Hi-res height field, and only when the window is smaller than this. |
| Toggle | What it does |
|---|---|
| Hi-res height field | Computes the field at Field floor resolution instead of the window size, so shrinking the window no longer turns terrain into a spiky needle-forest — every size matches the maximized look. Costs an extra field render below the floor; no effect at/above it. |
| Orthographic camera | Parallel projection — a clean relief-map look with no perspective stretch. |
| Base ground plane | Renders a floor so the fractal sits on the ground and cast shadows land on it, instead of a slab floating in the sky. |
| Bicubic height sampling | Catmull-Rom interpolation instead of bilinear — smoother terrain when zoomed in, at extra sample cost. |
| Auto lighting defaults | Fills sensible AO / soft-shadow / specular defaults for the 3D view when those Lighting FX knobs are still zero. Anything you set explicitly in Lighting & FX always wins. |
"Isolate object (drop background → transparent)" keeps only the fractal structure as a standalone 3D object over a transparent background — it exports as a cutout. Best paired with Show sky backdrop OFF (Lighting & FX) and Base ground plane OFF.
Two independent cull methods (use either or both):
| Control | What it does |
|---|---|
| Drop low-detail (keep filaments) | Removes cells whose local height gradient is below a threshold — culls flat background and smooth plateaus, leaving the fine filaments. |
| Drop amount | Fraction of the flattest cells to remove (a quantile). Higher = drops more background. |
| Drop colours | Also culls cells whose themed color matches a listed color. |
| Drop colours (hex) | Comma-separated RGB/ARGB hex (e.g. FF102030, 405060). Use Pick to eyedrop a color from the screen. |
| Colour tolerance | How close a cell color must be to a drop color to be removed. Higher = a wider range goes. |
In oblique raymarch mode, Relief 3D is a full member of the 3D shading pipeline. Everything in the Lighting & FX dialog applies:
- Soft shadows, DE-cone + screen-space AO, PBR (roughness/metallic/specular), sub-surface, IBL / HDRI environment, one-bounce reflections, tone-map / bloom.
- Volumetric fog and god-rays — set Fog density + Volume steps in Lighting & FX and the terrain gets real light shafts and atmosphere, including shafts against the sky just above the ridge. See the Volumetric Lighting Guide and Cookbook, but note relief needs higher fog density than a unit-scale 3D fractal and the fog is bounded to the terrain's height band — the relief-specific caveats are in the Relief 3D Cookbook → god-rays recipe.
Auto lighting defaults (§4) is the quick way to a good-looking 3D view: it seeds AO/shadow/spec only where you haven't set them.
The oblique raymarch runs on the GPU by default, with shading-pipeline parity for the surface (shadows, AO, PBR, IBL, reflections) and volumetric fog.
-
Toggle:
Ctrl+Shift+G, or Control Center → Color & Light → "GPU relief raymarch." -
Off falls back to the CPU sphere-trace — the parity oracle used to
verify the GPU output. The window title gains a
[RELIEF GPU OFF]suffix so you always know which path rendered. - The toggle is inert unless oblique raymarch mode is active.
Note
The two paths differ in the fog only. The GPU path scatters fog from the key light (Light 1) only — Lights 2/3 still light the surface, but only Light 1 carves god-ray shafts and tints the haze (via Anisotropy and Fog color). The CPU path scatters all three lights and supports the palette-mapped fog (Palette map). For a single hero shaft the GPU path is exactly what you want; for multi-light colored haze or palette fog, turn GPU relief off.
Use the CPU path when you want the reference image, multi-light/palette fog, or are debugging a GPU artifact; otherwise leave GPU on for speed.
The oblique 3D object exports as a watertight mesh:
- OBJ — with per-vertex color and smooth normals (for rendering / DCC apps).
- STL — binary (for slicers / 3D printing).
Export honours the isolation cull and these knobs:
| Control | Range | What it does |
|---|---|---|
| Height | 0.02 – 0.6 | Relief (emboss) height of the mesh, independent of the on-screen 3D height. Lower = clean bas-relief from any angle; higher = dramatic but spikier side-on. |
| Smoothing | 0 – 1 | 0 = raw detail (spiky); 1 = heavy despike + merge dendrites into clean ridges. 0.5 is the tuned default. |
| Detail (grid) | 128 – 1536 | Grid resolution on the longer axis. Higher = finer detail and bigger file. |
| File size cap (MB) | 0 – 50 | When > 0, the grid is clamped so the estimate stays under this size. 0 = unlimited. |
| Underside | 0 – 1 | Contour the back with the same smoothed relief instead of a flat base. 0 = flat back; 1 = back bulges as deep as the top rises. |
The panel shows a live Estimated size as you tune. Click "Export mesh (OBJ / STL)…" to save.
Note
The mesh Height and Smoothing are separate from the on-screen relief — a scene tuned to look dramatic on screen (tall, spiky) often prints best with a lower mesh height and ~0.5 smoothing so it reads cleanly as a physical object.
- Saved per region. Relief settings travel with a saved region, so a relief scene recalls exactly. Relief also carries through slideshow cross-fades.
- Lock Relief 3D (Control Center) — off: relief follows the region (on for relief regions, off for plain ones). On: relief stays as-is regardless of the region's saved setting — handy for auditioning relief across many regions.
- Gamma (Control Center, −100 … +100, default 0) is a post-FX brightness control that compounds with the theme's palette gamma — a quick way to lift or deepen relief contrast without touching the lighting.
- Animate camera azimuth (turntable), light angle, or fog over a Scene Engine timeline for video.
- Dedicated relief themes — Gold Relief, Marble Relief, and Neon Relief are tuned for the height shading. Smooth, low-noise themes generally read best.
- Long shadows come from low light elevation (screen-space) or low camera elevation + a low-elevation Lighting FX key light (raymarch).
- Tame the boundary with the Log height curve; drop Edge fade in if panned structure grows streaky arms at the frame edge.
- Shrinking the window makes needles? Turn on Hi-res height field and set a Field floor (e.g. 1080) so small windows match the maximized look.
- Performance: oblique raymarch cost scales with resolution × Anti-alias², plus the shading FX you enable. Tune at AA = 1, raise to 2–4 for the final frame. The GPU path is far faster for heavy scenes.
Relief reads through light and shadow, not hue — it's a strong choice if you
distinguish colors by hue with difficulty (e.g. red/green color vision
deficiency). Lean on Height scale, light elevation (shadow length), and
Relief strength for contrast. When adding colored fog or a themed palette,
prefer blue↔amber over red↔green, and use a yellow like FFFFCC00 where you'd
reach for red.
- Relief 3D Cookbook — copy-paste recipes.
- Volumetric Lighting Guide / Cookbook — fog + god-rays on relief terrain.
- Heightfield Relief Spike — the design/technical notes.