Checkerboard

The Checkerboard recipe makes a test pattern that might be useful for calibrating viewing apparatuses.

Above, PBRT rendered the scene.

Above, Mitsuba rendered the scene.

Description

The parent scene contains a square planar "board" made of matte material. The board is manipulated to use a "checkerboard" texture that varies the reflectance of the board between two spectra, in a 2-dimensional tessellation of alternating squares. One smaller dark square marks the center of the board. The camera views the board so that the viewing axis is perpendicular to the board's surface. A "sun" light is also aligned with the board so that its parallel rays are perpendicular to the board's surface. The sun light uses the CIE D65 "daylight" spectrum. Although the camera is between the sun and the board, the camera does not cast any shadow.

The scene is rendered with two conditions, one for the "left eye" and one for the "right eye". In each condition, the camera is shifted to the left or right, without rotation.

Several parameters of the scene are "broken out" for easy modification. These are:

• distance the distance from the camera to the board, in arbitrary units
• eyeSep the distance between the left and right eyes, in arbitrary units
• hFov the horizontal field of view of the camera, in degrees
• width the horizontal length of the board, in arbitrary units, also the number of squares horizontally across the board
• height the vertical length of the board, in arbitrary units, also the number of squares vertically across the board

Rendering

The executive script MakeCheckerboard.m produced the images above. It is located at here:

(path-to-RenderToolbox3)/ExampleScenes/Checkerboard/MakeCheckerboard.m

Users may specify values for the "broken out" scene parameters in MakeCheckerboard.m. The executive script will automatically write a [conditions file](Conditions File Format) that contains these values.