Lighting is a key component of how MARSO identifies the material properties of a 3D-scanned object. MARSO is designed to work with easily accessible lighting hardware, yet there are still key considerations to be made.
A single light works best when placed close to the lens, however, in scenarios where this is not possible, we suggest using multiple lights sequenced one light at a time.
Light Type
For best results, we recommend using as small of a light as possible. Sometimes this can be achieved by removing any diffusion or reflectors attached to an existing light fixture to expose just the bulb.
Works well
Point Light
Built-in camera flash
Small strobe
Single LED
Does not work
Softboxes
Umbrella lights
Reflectors
Polarisation Filters
Ring Lights
Small point light,
Crisp shadows,
Sharp highlights
Soft shadows,
Irregular light falloff,
Variable Intensity
Large effective area,
Soft shadows,
Soft / smooth reflections
Light Size
The size of the light source plays a key role in M-XR’s ability to identify roughness. By using a relatively small light source, glossy surfaces can be predicted as the reflections are sharper. It is worth noting that the size of the light source is however relative to how close the light is to the subject.
The example below illustrates this effect when the same-sized light is used for near / far scans
Smaller Light = Better Materials
Light Placement
The closer a light is to the centre of the camera, the less apparent shadows will be in the source photography. Reducing shadows, results in better material predictions.
When there are too many shadows, the shadows themselves can result in artifacts in the form of prediction errors or ambient-occlusion regions being baked into the material channels.
Minimal Shadows
Too much Shadow
As mentioned in Light Size, this distance is relative to the overall scene of the scene. An easier way to think about this is with angles - we recommend an angle of 3°. Anything higher than 5.5°, you should use multiple lights.
Generally speaking, the further a camera is from the subject, the more you can get away with a light being placed further from the centre of the camera - but closer is still preferable.