Though KeyShot has advanced Volumetric Lighting capabilities, there are some other methods you may want to experiment with when you need to create light rays or light beams or if you're using a version prior to KeyShot 8. To learn how to create light rays with KeyShot's volumetric lighting capabilities in later versions of KeyShot, see the article Volumetric Lighting in KeyShot: How to Create Light Rays.
Two Alternate Methods to Create Light Beams in KeyShot
Method 'A' is to model the actual light beam cones. Method 'B' is to use a volume (e.g. a cube) that envelops all geometry in the scene but doesn't include the camera. Both approaches rely on the new Cloudy Plastic material in KeyShot 7. If the Refractive Index of the Cloudy Plastic material is set to 1, then the material (the cone and the cube, in this case) can be effectively used to simulate volumetric effects like fog or light beams.
The Light Source
The light source is highly flexible but needs to be modeled a specific way to achieve the projected patterns desired. You can download the .stp/.x_t model here. Below is an illustration for the approach to take when modeling the light for a projected light beam.
The KeyShot sample scene contains Model Sets for each method. Go ahead and download, open it up and take a look. Next, we'll go over each method and provide the Pros and Cons of each.
Method 'A' - Light Cones
Open the scene (download above) and activate Model Set: Cloudy Plastic Cones.
- Renders faster
- Beams resolve faster
- Less noise
- The fog is isolated to the light beams (can also be a con)
- Beam cones must be modeled
- The beam geometry must fully intersect the ground and/or geometry in the scene
- Less accurate (although very close to Method 'B')
- Results inaccurate when beam intersects transparent objects
Method 'B' - Cloudy Plastic Envelope
Open the scene (download above) and activate Model Set: Cloudy Plastic Envelope.
- More accurate
- No need to model the beam cones
- The fog applies to the whole scene (can also be a con)
- Renders slower
- More noise
- Beams take longer to resolve without noise
- Camera cannot be inside the envelope
Can it Be Animated?
What about animating these lights? Can it be done? Yes, since the lights are geometry, and since it's KeyShot, you can animate the spot geometry and the light materials easily.
There have been a lot of requests from KeyShot users for volumetric shaders, and we're happy to say that KeyShot 8 introduced Scattering Medium that allows users to simulate particle scattering and volumetrics such as smoke and fog. Try it out and let us know what you think. You can learn more about the Scattering Medium in our Volumetric Lighting Quick Tip and in the KeyShot Manual.