blender-lighting

The saved excerpt is a snapshot from review. The external source remains the complete and most current version.

---
name: blender-lighting
description: Light Blender scenes professionally — three-point setups, HDRI environments, studio/cinematic/dramatic configurations, light groups, color temperature, soft vs hard shadows. Use whenever the user asks to "light the scene", "set up lighting", "make it look cinematic / dramatic / studio / outdoor / sunset", "add a key light", "use HDRI", or any lighting-related request. Make sure to use this skill even if the user does not say "light" — also covers "make it look professional", "studio shot", "moody atmosphere", "golden hour", "rim light". Pairs with blender-materials (lighting reveals materials) and blender-cameras (lighting + composition together = shot).
when_to_use: Any lighting setup or modification in Blender. Includes HDRI/environment lighting and individual lamp placement.
allowed-tools: Read Bash mcp__blender__execute_blender_code mcp__blender__get_scene_info mcp__blender__get_object_info
---

# Blender Lighting

Light scenes the way pros do: with structure, intent, and physically reasonable values.

## The five light types

| Type | Behavior | Use for |
|------|----------|---------|
| **AREA** | Light from a rectangular surface; soft shadows automatic | 80% of cases. Window, softbox, fluorescent panel |
| **SUN** | Parallel rays from "infinity" | Sunlight, moonlight, distant directional |
| **POINT** | Omnidirectional from a point | Bulbs, candles, small omnis |
| **SPOT** | Cone with falloff | Stage lights, headlights, focused beams |
| **HDRI/World** | 360° environment image | Realistic ambient, outdoor, product photography |

**Default rule**: Use **Area lights** for almost everything except the sun. Soft shadows come for free.

## Decision tree

```
What's the mood?
├── Studio / commercial → Three-point lighting (key+fill+rim) + HDRI fill 0.3
├── Outdoor / sunlit → Sun + HDRI sky environment
├── Indoor cinematic → Sun through window + HDRI low + practicals (lamps as Point)
├── Dramatic / noir → Single Spot at high angle, no fill
├── Stylized / cartoon → Three-point with high contrast + saturated key color
└── Unsure → Three-point with HDRI grounding (works for 90% of cases)
```

## Reference-look handoff

If the goal is to match an original/reference image rather than make a generally attractive render, chain-load `reference-look-calibration`. It owns measurement of hue/saturation/value, object extent, glow/aura color, and before/after look metrics. This skill should then apply the requested material/lighting/render changes within that calibrated target.


## Recipes

### Helper: `aim_at(light, target)` — required for subject-aware lighting

Recipe 1 below positions lights at fixed world coords with hardcoded rotations. That's fine for a generic 1m subject at the world origin. For ANY other subject (small jewellery, tall sword, sprawling building), you need lights aimed at the subject. Use this helper:

```python
from mathutils import Vector

def aim_at(light_obj, target):
    """Aim a light at a world-space target.
    target may be a Vector or a tuple/list (x, y, z) or a Blender object.
    """
    target_pos = Vector(target.location) if hasattr(target, 'location') else Vector(target)
    direction = (target_pos - light_obj.location).normalized()
    light_obj.rotation_euler = direction.to_track_quat('-Z', 'Y').to_euler()
```

### Helper: scene-aware light positioning

```python
from mathutils import Vector

def compute_scene_bbox_center(meshes):
    """Average bbox center over a list of mesh objects (world space)."""
    import bpy
    deps = bpy.context.evaluated_depsgraph_get()
    all_verts = []
    for o in meshes:
        eval_obj = o.evaluated_get(deps)
        em = eval_obj.to_mesh()
        for v in em.vertices:
            all_verts.append(o.matrix_world @ v.co)
        eval_obj.to_mesh_clear()
    xs = [v.x for v in all_verts]
    ys = [v.y for v in all_verts]
    zs = [v.z for v in all_verts]
    center = Vector(((min(xs)+max(xs))/2, (min(ys)+max(ys))/2, (min(zs)