Lights
Lighting Introduction
Along with objects and the camera, lights are a basic element in any LightWave Scene. In Layout, a Scene must always have at least one light. In fact, LightWave will not allow you to remove the last light source. If you really don’t need it, you can just turn its Light Intensity to zero or deactivate the light in the Scene Editor.
Lights in LightWave come in various forms. Shown here are the standard lights at normal sizes for all but Spot, which has been enlarged, and Photometric that has no IES file loaded yet. Third party lights can be added.
LightWave has several types of lights, and you can give them different names, colors, and attributes. Along with lens flares, volumetric and shadow casting options, you can control light with a high degree of precision. All of these features are found within the Lights tab of the Render Globals Panel.
Along with the several lights, LightWave also features radiosity and caustic light effects, which can add tremendous realism to your scenes.
Lighting in LightWave was completely overhauled in LightWave 2018 and improved in 2019. Listed below are the areas of change:
- Light power values are now listed in Lux (Lumen per meter squared)
- The Dome light has been removed and the Distant light given an Angle value like it
- The Environment light is used to add light from the backdrop for a scene
- Area and NGon lights now only point in one direction and can act as portals
- Lights can be visible to the camera
- All lights except point are sampled
- All lights can optionally affect volumetrics
- Ambient Intensity has been removed
New to 2019- MIS set to 512 samples instead of 256
- Distant light default angle set to 0.52 to better emulate the sun's soft shadows
LightWave lights don't have to act exactly like lights in the real world. For instance, you can choose not to see a LightWave light source, only its illuminating effect in the scene. This is actually a handy feature because unlike a movie set, you can place lights anywhere, including in front of the camera.
Video
Basic Light Attributes
Light Properties are to be found by selecting a light and hitting P or using the Properties button just to the right of the Current Item dropdown. This will bring up the Light Properties panel. This panel can vary quite a lot in size depending on what sort of light you’ve chosen, but they all have options at the top of the window in common.
- Clear all Lights - Doesn’t need much explanation. Since LightWave always requires at least one light in the scene, a single Distant light, in its default position will replace all the lights in your scene. This action cannot be undone.
- Lights in Scene - Just an info field that tells you how many lights you have in your scene.
Visible to Camera
A light with this option will be presented in the render as a visible light in the shape and size of its OpenGL representation. A light's size and shape can be altered in the Light Properties panel, or, in the case of Area and Linear lights, by using the Scale and Stretch tools in the viewport.
Though the Visible to Camera option may not be set in Light Properties, lights will still appear in reflections unlike earlier versions of LightWave.
Turning Cast Shadows on in the Shadows tab makes the light behave like an object casting a shadow created by other lights in the scene. Turning Cast Shadows on for a light is basically turning the light into a light blocker
Affect Volumetrics
Lights can optionally affect volumetrics for creating volumetric lighting effects or affecting volumetric primitives from the outside.
Volumetrics require an Inv Distance ^2 falloff. In 2019, this is set by default, but if your light is not affecting volumetrics check this setting first.
Example - Creating a Volumetric Light
MIS Samples
Some lights perform Multiple Importance Sampling, a more accurate version of the Importance Sampling introduced in LightWave 2015 that is available through the Global Illumination tab in Render Properties. It is more accurate because it is directly sampling the environment image, whereas the GI version is one step removed sampling the GI result of the environment map.
Buffer Group
See the Light Groups page.
Normalize
There is a Normalize toggle in most Light Properties windows. Light intensity is now set in Lux, which is Lumen per meter squared. This means that as your lights change size so does their intensity. With Normalize off, a smaller light of a given intensity will give out less light, a bigger light more. With Normalize on, the intensity stays the same. It might appear to become dimmer in some cases but this is merely because the light output is being spread over a larger area.
The area of a Distant light will decrease as you reduce the angle in the panel, and thus its power diminishes if Normalize is not checked. 0° is a special value, and the Distant light will behave the same Normalized or not, with hard shadows.
Converting from 2015
- Area * 3.14
- Distant * 3.14
- Dome * 1.57 (converted to Distant light with the appropriate angle)
- Linear * 3.14
- NGon * 3.14
- Photometric no changes, but see note
- Point * 3.14
- Spherical * 6.28
- Spotlight * 3.14
- 3rd party lights * 3.14
Photometric has no changes because Photometric lights are based on the IES data they contain that should now be accurate, rather than needing tweaking
Pi (either half, full, or double) is approximately the same light output as previous LightWave versions' 100%