2.4. Effects

This atmospheric glow effect makes a fast-rendering glow effect. It is based on the light source glow effect from POV-AFX, written by Marcos Fajardo, but has been heavily modified.

Syntax is:

glow {
  type 0 | 1 | 2 | 3
  location VECTOR
  size FLOAT
  radius FLOAT
  fade_power FLOAT
  color COLOR
  TRANSFORMATIONS
}

You can specify glows individually, or attached to a light_source. If created in a light source, they will be automatically initialized with the light's position and color (though transforming the light source will not give the expected result).

Choose a glow type from 0, 1, 2 or 3. Type 2 and 3 glows are not completely implemented yet, but 2 will be based on the exp() function and 3 will simulate a sphere with constant density.

The size keyword adjusts the scale of the glow effect. It is not an absolute size, just a scaling amount (because some glows are infinite). It does not quite work properly yet, it causes strange effects with changing distances of objects behind the glow.

The radius keyword specifies a clipping radius confining the glow to a circular area perpendicular to the ray. If the glow is still visible at this radius, it will make a sudden transition.

The fade_power keyword allows you to provide an exponent to adjust the falloff with.

[Note]Note

A glow is not an object, it is an atmospheric effect. Therefore glows cannot be used in CSG operations.

Transformations on a glow only affect the location vector. So will scale not change the size or shape of a glow, but scale the location coordinates.