Inverse Lighting with a Monte Carlo Method

Patrick Poulingeas, Vincent Jolivet, Dimitri Plemenos

LMSI

Equipe Modélisation et Infographie Intelligente

Usual Lighting Process

designer‘idea of lightingData:

Scene GeometryMaterial properties

Specifications given by the designer:Light source(s) position(s)

Light source(s) physical properties

Scene

Rendering

If the scenedoesn’tagree

thedesigner

Inverse Lighting Process

Data: Scene Geometry

Material propertiesdesigner‘idea of lighting

Inverse Lighting Method computing:-Possible light source(s) position(s)-Possible light source(s) properties

Scenes

Rendering

Finding the Light Source Positions

Patches to light

Potential light source

positions found by a

Monte Carlo method

Finding the Light Source Positions

Reducing the number of potential

light sources

with:

1. A heuristic using form

factors computed in

radiosity

2. Constraining the lights to

be at the ceiling

Example of solution found

The patches to be lit are painted in purple in the right picture

Another example of solution found

The patches to be lit are painted in purple in the right picture