The Sky procedure is an environment map that generates images of a planetary atmosphere as seen from the surface of the planet. Parameter sets enable you to control the composition of the atmosphere and the cloud layer. If no floor is specified, the environment below the horizon is a vertical mirror reflection of the environment above the horizon. If a floor is specified, it must be given an altitude and other variables to control the positioning of a color pix file texture map on the surface.
| Argument Name | Absolute Range | Useful Range | Default | Description |
| floor_texture | no default | pix file name for floor texture 24 bits | ||
| cloud_texture | no default | Mask file name for cloud texture 8 bits | ||
| cloud_altitude | 0, 1 | 0, 0.5 | y coordinate of cloud layer as a fraction of sky_thickness (if Y-up) | |
| space_samples | 0, infinity | 1, 10 | 5.0 | # of samples above clouds |
| floor_samples | 0, infinity | 0, 3 | 1.0 | # of samples in front of floor |
| cloud_samples | 0, infinity | 0, 3 | 5.0 | #. of samples below clouds |
| air_density | 0, infinity | 0, 10 | 1.0 | Density of air molecules |
| dust_density | 0, infinity | 0, 3 | 0.0 | Density of dust particles |
| sun_azimuth | -infinity, infinity | 0, 360 | 145.0 | Rotation of sun vector about vertical vector |
| sun_elevation | -infinity, infinity | -10, 90.0 | 45.0 | Angle of elevation of sun vector relative to floor |
| sun_size | 0, infinity | 0, 30 | 0.531 | Radius of sun's disc in degrees |
| sun_blur | 0, infinity | 0, 50 | 1.0 | Radius of halo around sun in degrees |
| sun_halo_brightness (triple) | 0, infinity | 0, 1 | 0.2,0.3,0.2 | Multiplicative color for halo around the sun |
| sky_brightness (triple) | 0, infinity | 0, 10 | 1.0, 1.0, 1.0 | Multiplicative color for the sky |
| sun_brightness (triple) | 0, infinity | 0, 10 | 1.0, 1.0, 1.0 | Multiplicative color for the sun |
| floor_altitude | -infinity, infinity | -100, 100 | -1.0 | y coordinate of the floor (if y-up) |
| cloud_density | 0, infinity | 0, 5 | 1.0 | Density of the sky |
| cloud_radius | 0, infinity | 0, 50 | 20.0 | Radius of halo around sun |
| cloud_width_mult | -infinity, infinity | -0.2, 0.2 | 0.1 | Scaling factors for cloud map position on floor |
| cloud_depth_mult | -infinity, infinity | -0.2, 0.2 | 0.1 | " " " |
| cloud_blurmult | 0, infinity | 0, 10 | 1.0 | Scaling factor for cloud blur size |
| cloud_bluroffset | 0, infinity | 0, 1 | 0.0 | Offset for cloud blur size |
| cloud_threshold | 0, infinity | 0, 1 | 0.5 | Threshold for presence of clouds |
| cloud_brightness | 0, infinity | 0, 10 | 1.0, 1.0, 1.0 | Multiplicative color for ambient cloud illumination |
| cloud_sunset_brightness | 0, infinity | 0, 500 | 300, 300, 300 | Multiplicative color for front lighting |
| cloud_power | 0, 1 | 0, 1 | 1.0 | Exponent for cloud density falloff |
| floor_width_mult | -infinity, infinity | 0, 10 | 1.0 | Scaling factors for color map position on floor |
| floor_depth_mult | -infinity, infinity | 0, 10 | 1.0 | " " " " |
| floor_width_offset | -infinity, infinity | 0, 1 | 0.0 | Offsets for color map position on floor |
| floor_depth_offset | -infinity, infinity | 0, 1 | 0.0 | " " " " |
| floor_blurmult | 0, infinity | 0, 10 | 1.0 | Scaling factor for floor blur size |
| floor_bluroffset | 0, infinity | 0, 1 | 0.0 | Offset for floor blur size |
| floor_color (triple) | 0, infinity | 0, 255 | 255, 255, 255 | Color of floor |
| sky_radius | 0.01, infinity | 0.01, 300 | 50.0 | Radius of planet as a multiple of sky_thickness |
| sky_thickness | 1, infinity | 100, 10000 | 1000 | Thickness of atmosphere |
| total_brightness | 0, infinity | 0, 10 | 1.0 | Scales the overall brightness of environment |
| has_floor | TRUE FALSE | TRUE | Flag setting whether or not a floor is used. |
“Sky” is an environment texture.
