Environment Light object

Whether or not this object is displayed. Turn on the checkbox to have Houdini use this parameter, then set the value to 0 to hide the object, or 1 to show the object. If the checkbox is off, Houdini ignores the value.

Caches object transforms once Houdini calculates them. This is especially useful for objects whose world space position is expensive to calculate (such as Sticky objects), and objects at the end of long parenting chains (such as Bones). This option is turned on by default for Sticky and Bone objects.

See the OBJ Caching section of the Houdini Preferences window for how to control the size of the object transform cache.

Object is capable of being picked in viewport.

Script to run when the object is picked in the viewport. See select scripts .

Object to point to. Constrains an object so its -Z axis always points at another object’s origin.

When specifying a look at, it is possible to specify an up vector for the look at. This controls the roll of this object when looking at the look at object.

The sampling style for environment illumination. Environment lighting is computed with raytracing by sending rays out into the hemisphere above the shaded surface to analyze the amount of light arriving at the surface from different directions.

Which rendering mode you choose to use will depend on the type of environment illumination as well as the geometry in your scene.

The sampling quality multiplier for the light. A value of 1 will use the ray sampling parameters (Min Ray Samples) from the output driver directly. Other values will proportionally increase or decrease the sampling quality.

Specifies a geometry object that can be used to optimize sampling of environment lights in enclosed scenes. The portal geometry describes to the renderer where light can enter the enclosed scene, so that the sampling algorithm can concentrate on the parts of the environment that actually contribute lighting to a pixel. Normally, the portal geometry should be a geometry object that is not rendered, so that it does not cast shadows on the scene, and that has only a single layer of surface visible from any point in the scene - so that illumination is not multiply counted.

A correctly configured portal should produce the same rendered result as when the portal is disabled, but with much less noise. Portals should normally not be used in outdoor scenes where the environment map is fully visible, or when the environment map contains sharp variations in intensity - since in these cases the standard direct lighting algorithm may produce better results.

Using an environment light with a portal is equivalent to creating a standard geometry light with physically correct attenuation, no intensity normalization, and transform into this object enabled.

Maximum distance from the sample point to consider geometry for irradiance/occlusion.

Half-angle over which to send rays for irradiance/occlusion. 90 degrees is a full hemisphere.

Turns on an automatic optimization that will reduce the number of samples when there is little variation in occlusion above the sample point. This can improve performance at the expense of some possible flickering or additional noise. Adaptive sampling will only take effect with more than 64 samples.

Automatically create a “sky and ground” environment map. When this parameter is on, the Environment Map parameter (on the Environment tab) will be disabled.

The resolution (in pixels per cube side) of the environment map.

The type of direction to calculate. Either Away from Sun or Towards the Sun.

The direction vector for the sun.

The Euler rotation angles to align -Z axis with the Calculated Vector.