Measured quasi-diffuse material (mqdiffuse)

Measured quasi-diffuse material (mqdiffuse)#

Parameter

Type

Description

Flags

filename

string

Filename of the volume to be loaded.

grid

VolumeGrid object

When creating a grid volume at runtime, e.g. from Python or C++, an existing VolumeGrid instance can be passed directly rather than loading it from the filesystem with filename.

accel

boolean

Hardware acceleration features can be used in CUDA mode. These features can cause small differences as hardware interpolation methods typically have a loss of precision (not exactly 32-bit arithmetic). (Default: true)

This plugin models the reflection of light by opaque materials with a behaviour close to diffuse, i.e with no strong scattering lobe. Assumptions are as follows:

  • The material is isotropic. Consequently, only the azimuth difference matters.

  • The material is gray. Consequently, no spectral dimension is used.

The data dimension order is (cos_theta_o, phi_d, cos_theta_i). The sampling routine is uniform cosine-weighted (i.e. the same as for the diffuse plugin).

Warning

Table values are not checked internally: ensuring that the data is consistent (e.g that the corresponding reflectance is not greater than 1) is the user’s responsibility.