LightWave 2018

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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.

New to 2018

Lighting in LightWave has been completely overhauled. 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

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 Default 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.

New to 2018

The Ambient light setting from previous versions of LightWave has been removed.

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.

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 2018, this is set by default, but if your light is not affecting volumetrics check this setting first.


Example

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

New to 2018 in many of the light types is the Normalize toggle. The 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

Loading a scene from a previous version of LightWave will automatically convert scene lights to the correct values, but if you need to manually convert a 100 % light from the old percentage scale to Lux you can do so according to the following rules:
  • 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%