Sprite Object: Lights
The Sprite object can also generate simple lights instead of a primitive object.
If you select 'Light' in the 'Sprite type' drop-down menu, the interface changes and you see the available parameters for the lights:
For the 'Groups Affected' tab and the buttons at the bottom of the interface, please see the 'Common interface elements' page.
Checking this switch means that the generated lights will not contribute to the scene illumination. This is probably what you want most of the time. Generating thousands of lights which do illuminate the scene will enormously increase render times!
The remaining parameters in this section are only available if 'No Illumination' is unchecked.
Corresponds exactly to the 'GI Illumination' switch in the General tab of the light parameters in the attribute manager. Please refer to the Cinema 4D documentation for full details.
The brightness of the light. Note that this is the illumination brightness, NOT the visible brightness (see below).
This drop-down has four settings. For more details of these shadow types, please see the Cinema 4D reference documentation.
The light will not produce shadows.
The light will generate shadows using low-resolution shadow maps for speed and low memory usage.
The light will generate raytraced, hard shadows.
The light will generate area shadows.
These settings are only available if 'No Illumination' is unchecked. They allow you to set the falloff for the light cast by the light sprite. They are identical in meaning to the illumination falloff settings for the lights in Cinema 4D; please refer to the C4D documentation for details.
This is the section that you will probably use most frequently, in order to generate visible lights in the scene. The parameters in this section correspond to the parameters for a Cinema 4D light object, and more information can be found in the C4D documentation.
This drop-down has three options:
The light is not visible.
The light will be visible in the scene (the same as selecting 'Visible' from the 'Visible light' drop-down in a Cinema 4D light object).
This is the same as selecting 'Volumetric' from the 'Visible light' drop-down in a Cinema 4D light object.
The same as the corresponding setting in the Cinema 4D Light object, Visibility tab.
This is the brightness of the visible light, NOT the light brightness when used for illumination.
This value determines the 'inner distance' for the visible light. It is the same as the Cinema 4D parameter of the same name, but since the size of the light can vary depending on the particle size, this is a relative (percentage) inner distance rather than an absolute one in scene units.
This section gives access to all the noise settings which you find in a Cinema 4D light object. Please refer to the Cinema 4D reference documentation for details on how to use these settings.
Lens Effects quicktab
The sprite lights can now use lens effects. To use them, first turn them on 'Use Lens Effects' then drag a light whose lens effects settings you want to use into the 'Source' field.
You can set the source light to be invisible in the editor and renderer. Al lit does is provide the lens effects settings to use; you can edit these in the source light, see the Cinema 4D documentation for details.
Using lens effects is a good way to generate good-looking stars, fireworks, etc. - anything which needs a lot of brightness and glow.
Note: lens effects requires that the Lens Effects videopost effect is added to the render settings. If this effect is not present it will be added automatically by the Sprite object, but it won't be added again if it is already present. Be aware that this effect will not be removed or disabled if you disable lens effects in the sprite object or source light.
Use Lens Effects
Check this switch to use lens effects on the sprite lights.
Drag the light which is the source of the lens effects into this field.
Notes on using the Sprite Lights
1. All changes in light parameters are handled by the Light modifier. The Sprite object sets the initial parameters of the light but does not alter them once the light has been generated.
2. The light will always take its colour from the particle colour. This can be changed with a Color modifier.
3. For visible lights, there is no outer distance setting. The outer distance is the same as the particle radius (so this may need to be quite large). The radius can be changed with a Scale modifier.