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Aphelion

Aphelion Editor

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5 — Normals and relighting

A normal pass stores surface direction as colour (red = X, green = Y, blue = Z). Aphelion can generate one from a depth pass, generate one procedurally, and use it to relight or restyle a plate.

You will build: a depth pass → Normal From Depth → a relight via Depth Relight, plus a stylised normal-pass look.

Part A — Generate a normal pass

There is no generic node that consumes a normal socket; a normal pass is a frame, so it flows through the normal video chain.

  1. Build a depth pass (see Depth maps and effects): Depth Gradient or Depth Shape + Depth Noise.
  2. Add a Normal From Depth node.
  3. Connect Depth*.depth → Normal From Depth.depth.
  4. Connect Normal From Depth.normal → Viewer.frame to inspect it.

You now have an RGB frame encoding surface direction. For a purely procedural normal field with no depth pass, use Normal Shape instead — it has a Shape → Shape primitive choice.

Part B — Relight with the depth surface

Depth Relight derives its own normals from depth and re-lights the image, so it needs the frame and the depth — not a normal pass.

  1. Chain: Video Input → Depth Relight → Viewer.
  2. Connect your depth pass into Depth Relight.depth.
  3. Set the light:
    • Light → Light X = -50, Light → Light Y = -65 (upper-left key).
    • Surface → Relief = 300 — how much the depth surface slopes; high values exaggerate relief, low values flatten it.
    • Light → Strength = 100, Light → Ambient = 20.
  4. Turn on Depth → Invert Depth if the light reads inverted (the effect assumes white = far).

Animate Light X/Light Y across the shot to sweep the key light, or drive them with an Oscillator (see Driving properties).

For an edge-light look instead, use Depth Rim Light with Rim → Strength.

Part C — Restyle the normal pass

Because the normal pass is just an image, every colour and stylise node applies:

ChainResult
Normal From Depth → Color GradingRebalance the pass (Primary → Saturation 170, Contrast 120)
Normal From Depth → DuotoneTwo-colour normal map (Colors → Shadows / Highlights)
Normal From Depth → PosterizeBanded, screen-print normal look
Normal From Depth → BloomGlowing relief ridges
Normal From Depth → Displace.displaceUse normals to warp the plate itself
Normal From Depth → Bump Map.height_mapFake surface bumps from the normal pass

To composite a normal-pass look over the plate, Merge it as the foreground with a low Opacity, or use a Dissolve.

Part D — Bump and relief from a height map

Bump Map takes a height map, not a normal pass, and shades it with a light:

  1. Chain: Video Input → Bump Map → Viewer.
  2. Connect a Height Map node (or a Depth Noise) into Bump Map.height_map.
  3. Set Bump → Intensity = 10, Light → Light X = -50, Light → Light Y = -70.
  4. Raise Bump → Smooth if the relief is too harsh.

Use Height Map → Height → Scale (default 32) to change the surface frequency.

Part E — Position pass for depth compositing

Position Map outputs a world-position pass. Like normals it is an RGB frame, so use it as a stylised background, a Displace map, or a colour-graded element — useful for technical-looking VFX and data-visualisation styles.

Troubleshooting

SymptomFix
Relight has no visible effectDepth is flat (all one value). Add contrast with Depth Noise or a Depth Shape
Relief looks invertedToggle Depth → Invert Depth, or swap the light's Y sign
Normal pass is mostly flat blueThat is correct for a front-facing flat depth plane. Add depth variation for curvature
Bump Map is too noisyRaise Bump → Smooth, or lower Height Map → Scale