Knowledge Base

Article Number: 65 | VC4 | VC3 | Post Date: June 28, 2018 | Last Updated: June 28, 2018

How can I indicate that lights are on my vehicle without using the volumetric lighting halo effect? How can I show lights on in daytime lighjting? Is there a way to rig a vehicle with lights so I can reuse it?

The volumetric lighting tool automatically enables a spherical source light “halo” effect. This is a great way to indicate to your viewer that light being cast throughout the scene is originating from that location. For a spot light, like a headlight, the source light itself is an omnidirectional light which is intended to provide illumination near the light sources, associated with scattered light from lens elements and housings. This is superimposed with a spot light which is intended to provide the primary directional light. The attenuation of this source light can be controlled in the “source” menu. The volumetric halo for the source omnidirectional light is controlled in the “volume” menu using “start-source”, “end-source”, and “density-source”.   

The volumetric halo can be disabled simply by setting “density-source” to 0%. Likewise, if you desire to have no volumetric effect whatsoever, you can also set “density” to 0% in the volume menu, or simply deselect “use” in the volume menu. Here we see the source has no volumetric effect applied. The omnidirectional source lighting however is still shining light back on the headlight polygons. This is another way to indicate lights are on. 

This can be further improved by simply creating another spotlight and turning it to point directly to the headlight polygons. One can even select a rectangular shaped profile, which will better match the shape of headlights and taillights. Here we show one such spotlight. It’s hotspot and falloff are set to the same value. A small attenuation distance is used so that light rays are not accidentally shot behind the headlight. The “shadow” option is disabled, as are the source and volumetric lighting options. 

Here we see the rendered result.

Here we see the rendered video.

Below we see the taillights applied in daytime lighting. Note the outward facing lights were switched off, and only the inward facing spotlights are left on. Both the on/off state and the intensity of these lights can be controlled as a function of time. We can use the diagram tool to easily illustrate things like turn signals or even taillights (which increase in intensity when the driver depresses the brake pedal).

Finally, note our lights and vehicle object are combined into a single group object. This allows us to save a copy of our .vc4 file (with only the group object) to use in future cases. This is also a handy way of reusing streetlight objects. 

Tags: Headlights, taillights, no halo, lighting halo, volumetric effect, volumetric lighting, grouping lights, rigging vehicle with lights.

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