!viewpoint

Specifies the viewpoint position by coordinates.

Default: x = (xmin + xmax)/2.0, y = ymin + 1.5 (ymax – ymin), z = zmin + 1.5 (zmax – zmin)

look_at_point

Specifies the look at point position.

Default: Center of data

up_direction

Specifies the view frame in viewpoint, look_at_point and up_direction.

default: 0.0 0.0 1.0

View coordinate frame

• Origin: look_at_point
• Z-axis: viewpoint - look_at_point
• X-axis: up_direction × z axis

Figure 7.4.11: View Frame Determination Method

Figure 7.4.12: Example of !viewpoint, look_at_point and up_direction Setting