Lighting Theory in Lightwaveby Jonathan WondruschGoals of this Tutorial•Provide you with a better understanding of light and shadows•What to consider when lighting your scenes•How to choose the right light(s) in Lightwave and use them to the best effect possibleTypes of Lights in LightwaveDistant Light Distant Lights are a unique type of light in Lightwave. They are the only light source to create parallel rays of light. Spotlight Spotlights emit light in the shape of a cone. Spotlights have special properties, Cone Angle and Soft Edge Angle that are unique to Spotlights.Point Light Point lights emits light from a single point in a radial, as opposed to the parallel rays of a distant light. Linear Light Linear lights are very similar to point lights in that they emit light in all directions. The difference is the type of shadows that are achievable with Linear Lights, because they use multiple points to emit light from, creating softer shadows known as penumbra. Area Light Area lights are similar to Point Lights as Linear Lights are, however, they emit from a greater number of points, creating a softer penumbra. Note: An easy way to understand the difference between Point, Linear and Area Lights are to think of them as 0D (a single point), 1D (a single line), and 2d (an area, or shape)Light Properties in LightwaveAmbient Color/Intensity: Describes the color and intensity of light that exists in your scene, but is not emitted from the lights you place there. To have the most control over the lighting of your scene, place to 0%.Light Color/Intensity: The color and intensity of the current light you have selected.Intensity Falloff: How far the light travels in your scene.Linear – Light intensity decays at an even rate.Inverse Distance – Intensity decays by a rate of 1/Distance from your light. The decay is much faster than Linear.Inverse Distance ^ 2 – Decays at a rate of 1/Distance^2, or a much faster decay rate than Linear or Inverse.Intensity Falloff Note: When using Intensity Falloff, you may notice it gets too dark, too soon. Other than the Range/Nominal Distance tool, you can also adjust Light Intensity to compensate for this effect.Range/Nominal Distance: The distance at which falloff begins to occur.Linear/Area Light Quality: The lower this is, the more grain you have in your render.Spotlight Cone Angle: Describes the size of your spotlight.Spotlight Soft Edge Angle: Determines how soft the edge of your spot is. 0% is sharpest possible, going up to the size of your Spotlight Cone Angle, yielding the softest edge possible.Don’t Forget Your ShadowsShadow Type- Ray Trace calculates the areas of your scene that are covered in shadow by following rays of light emitted by your light source, and casting a shadow where the rays do not reach.-Shadow Map is an option only available for Spotlights. The larger the Shadow Map Size, determines how clean the shadow is. Fuzziness determines how crisp the shadow is.Lighting Considerations for Your SceneReferenceThe first step to take in lighting your scene successfully is to find photographic reference that is similar to your scene, that you will be able to refer to. Think about things such as, what is the main light source? How defined are your shadows? What color is your light? Interior or Exterior?The setting of your scene heavily determines the types of lights you will use, the colors of the light and their intensity.- Interior Lighting Note – Two typical varieties: Tungsten, which has a orange hue, and can be found as a light bulb usually; and fluorescent, which has a slight green hue.Time of DayThe time of day controls the intensity and color of your light as well. Just as significant, the saturation of your colors and the contrast in your shadows is greatly affected by time of day.- Twilight/Dusk – Soft lights and shadows of low intensity, ranging across the spectrum. Usually colors take on pink, blue, purple hues.- Midday – High intensity lighting, and very crisp shadows. Usually takes on a slightly blue hue.- Late Afternoon/Early Evening – Medium intensity yellow light, with soft shadows.- Sunset – Long, soft shadows with medium intensity light. The light contains a large range of colors, predominantly from orange to red in hue.- Night – Very heavy blue cast to all objects in a scene. Shadows are difficult to discern, usually very soft if lit by moonlight. Weather- Overcast weather has a significant effect on the shadows in your scene. You get more diffuse lighting and softer shadows.Examples of Different LightingInterior Lighting MiddaySunset NightSelecting the Right LightMost scene’s will not use only one light. Each scene is independent in its lighting needs, and should be dealt with on an individual basis. While mediocre results can be achieved by simply turning up the ambient intensity and throwing in a point light or two, this leaves you with the same result and feeling every time which becomes repetitive. Each light has its own benefit and can usually be used to good results.Distant LightRendered with a single Distant Light, the shadow of the object is very crisp, and is even in its tone. All the light in the scene is cast in a single direction, instead of naturally bouncing in all directions as light actually does.Point LightWith a single point light, you still get a crisp shadow like you would with a distant light, however the shadow now has different values because of the way light has bounced around the scene and has lit the shadow near its edges.SpotlightsThe spotlight on the left has a cone angle of 30 degrees and a soft edge angle of 30 degrees, providing a very soft edge to the light, but still containing crisp shadows. The middle image has a cone angle of 30 degrees, and only a 5 degree soft cone angle, making the edge of the light much more defined. Both the first two images used ray trace shadows. The last image has is the only one to use Shadow Maps on the spotlight, adding to a much softer cast shadows.Linear LightLinear lights are very similar to point lights, except that it emits from multiple points along a line instead of from a single point. This creates areas known as umbra, or the core shadow, and penumbra, or the areas that are hit by some rays of light, but not by all. To achieve this effect, all you need to do is to scale your linear light so that it is larger than the object(s) you are lighting.Area LightsArea lights can usually