Lights¶

The Designer ships four kinds of light: Directional, Point, Spot, and IBL (image-based lighting from an HDR). Most scenes use a single Directional + ambient; IBL is the right choice for hero PBR renders.

Light kinds¶

Directional¶

Light from one direction, infinite distance. Like the sun.

Rendering > Light > Add Directional. Parameters:

Parameter	Default	Effect
color	white	Light color (CSS hex or RGB)
intensity	1.0	Multiplier
direction	(-0.3, -1, -0.3)	Unit vector pointing FROM the light
shadows	on	Cast shadows from this light
shadow_blur	1.0	Soft shadow blur radius (pixels)

The default direction points "down and slightly forward": usually flattering for a subject facing the camera.

Point¶

Light from a single point, attenuated by distance. Like a bare bulb.

Rendering > Light > Add Point. Parameters:

Parameter	Default	Effect
color	warm white	Light color
intensity	100	Higher than Directional because point lights attenuate
position	(cursor)	World position
radius	0.1	Sphere radius for soft shadows (0 = sharp)
range	500 px	Falloff range

Point lights are ideal for fairy lights, candles, and any localized light source.

Spot¶

Point light constrained to a cone.

Rendering > Light > Add Spot. Parameters:

Parameter	Default	Effect
color	white
intensity	200
position	(cursor)
direction	(0, -1, 0)	Cone axis
inner_angle_deg	30	Full intensity inside this cone
outer_angle_deg	45	Falloff between inner and outer
range	800 px	Falloff range

Spot lights are stage lights, flashlights, theatrical lighting.

IBL (Image-Based Lighting)¶

Rendering > Light > Add IBL… opens an HDR picker. Pick a .hdr or .exr panorama; the renderer uses it for ambient light and specular reflections.

The Designer ships a small built-in IBL library (forest noon, studio, sunset, night street, blueprint), plus accepts any HDR.

IBL is what makes the Blue Morpho's iridescence pop in the tutorial chapter 7 render.

Light gizmos¶

Lights are invisible in the canvas by default. View > Show Light Gizmos draws small icons at light positions and arrows for directions / spot cones. Click a gizmo to select the light.

Group lighting¶

Multiple lights are common. Use the Sets tab to group related lights, then toggle the set's visibility for A/B comparisons.

Shadows¶

shadows: on enables shadow casting from this light. Each light's shadow has:

shadow_blur: pixels of soft-edge blur. 0 = hard edges, 3+ = area-light look.
shadow_density: 0..1 fraction of darkness. 1.0 = fully dark shadows, 0.7 = partial.

For multiple shadow-casting lights, the renderer accumulates them correctly. Production / Final quality presets resolve shadows without bias artifacts.

Performance¶

Light kind	Per-frame cost (path-traced render)
Directional	~1 ms
Point	~1 ms
Spot	~1.2 ms
IBL	~3 ms

Costs add roughly linearly. A scene with one Directional + one IBL is the typical setup.