7.18. SpotLight3DS — 3DS spot light

The SpotLight3DS class stores all parameters of the spot lights as they are stored in 3DS files. The main purpose of this class is to ensure that data doesn’t get lost during file conversions.

This light sources can also be used for RenderMan renderings. However, not all of the parameters are currently taken into account in the corresponding RenderMan shader (see below).

class SpotLight3DS(name = "SpotLight3DS", enabled = True, intensity = 1.0, color = (1, 1, 1), see_cone = False, roll = 0.0, outer_range = 0, inner_range = 0, attenuation = 0, rectangular_spot = 0, shadowed = False, shadow_bias = 0, shadow_filter = 4.0, shadow_size = 256, spot_aspect = 0, use_projector = False, projector = 0, overshoot = False, ray_shadows = False, ray_bias = False, hotspot = 43, falloff = 45, target = (0, 0, 0))

enabled is a boolean flag that can be used to turn the light source on or off.

intensity is the overall intensity of the light source. The higher the value, the brighter the light.

color defines the color of the light source. It must be a sequence of 3 floats containing RGB values.

see_cone ...

roll ...

inner_range and outer_range specify an intensity range based on distance. Any parts of the scene that are nearer to the light source than inner_range are fully illuminated. Within the range between inner_range and outer_range the brightness drops off to 0 and objects further than outer_range are not illuminated at all. These range values are only taken into account when attenuation is not 0.

rectangular_spot ...

If shadowed is set to True the light casts a shadow.

shadow_bias is a small value greater than 0 that is used to prevent invalid self-shadowing (i.e. so that a surface element doesn’t shadow itself).

shadow_filter specifies the size of the filter when doing shadow map lookups. The higher the value the blurrier the shadow.

shadow_size defines the size of the shadow map. The shadow map will always be square and have a width of shadow_size pixels.

spot_aspect ...

use_projector ...

projector ...

If overshoot is True the light virtually becomes a point light source, i.e. it also illuminates the parts of the scene that lie outside its cone but the shadow is still restricted to the cone.

ray_shadows ...

ray_bias ...

hotspot This is the angle (in degrees) of the “inner” cone which is fully illuminated.

falloff This is the angle (in degrees) of the “outer” cone. The light intensity between the inner and outer cone drops off to 0. The region outside the outer cone is not illuminated (unless overshoot is activated).

target is the target point that the light source aims at.

The following parameters are used in the corresponding RenderMan shader, all other parameters are currently ignored:

• intensity
• color
• falloff
• hotspot
• attenuation
• inner_range
• outer_range
• overshoot
• shadow_bias
• shadow_filter
• shadow_size