Lights - Arnold for Katana
Further Reading |
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See also Lights in the Arnold User Guide |
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Light manipulators available via shift+A (press T for the center-of-interest controls)
The built-in lights that are available in Arnold.
Arnold lights are available in the Hydra-based viewer. Activate the new manipulators by pressing Shift+A in the viewer, and compatible lights will have a ring of manipulator icons displayed with can be clicked+dragged to modify those aspects of the light(s) selected. The available manipulators are as follows:
- Cone angle (left-right) and penumbra angle (up-down) for spot lights
- Radius for spot, disk, photometric and point lights
- Spread for disk and quad lights
- Aspect ratio for spot lights
- Roundness for quad and spot lights
More information about light samples and removing noise can be found here.
Arnold lights available in ArnoldShadingNode
Cylinder Light
The cylinder_light shape simulates light from a cylindrical area source (tube shape).
Disk Light
The disk_light shape simulates light from a circular area source (flat disk).
Distant Light
This is a parallel light from a distant source, specified in terms of a direction vector. Often used to model sunlight.
Mesh Light
In situations where conventional light shapes will not suffice, mesh lights are more suitable. Mesh lights can be used to create interesting lighting effects that would not be possible any other way. For example, effects such as neon lighting or a car light motion trail effect can be achieved more easily with mesh lights.
Photometric Light
Photometric light found under the Arnold>Lights menu
Photometric lights use data measured from real-world lights, often directly from bulb and enclosure manufacturers themselves. You can import IES profiles from companies such as Erco, Lamp, Osram, and Philips; their IES files provide accurate intensity and spread data for a given light model.
Point Light
Although named point for historical reasons, this light source can model light either from a (theoretical) point source, or from a sphere (the latter being more realistic in most cases, and producing less sharp shadows). The light is cast evenly in all directions.
Quad Light
Simulates light from an area source (a quadrilateral, specified by four vertices). It can be used to model light from an extended source (fluorescent strip lights) or in some circumstances from a window.
Light Filters
The following light filters are available in KtoA:
Barndoors
This light filter can only be used with spot lights. Barn doors are opaque moving panels attached to the sides of the light's opening. They are typically used in theatrical and film lighting for additional control over the shape of the light beam. This barndoor filter introduces four barn door flaps. Each barn door flap has three parameters.
Gobo
The gobo filter can only be used with spot lights. In theatrical stage lighting, a gobo (or "cookie," slang for Cucoloris ) is a thin sheet of metal with holes used to break up the light beam into an irregular, more natural pattern such as tree leaves, etc.
gobo light filter -> spotlight
Light Blocker
Light blockers give flexibility to the lighting TD. They can be used as an artificial method of masking light in a scene without the overhead of adding additional geometry. Used carefully, they provide a degree of artistic freedom, allowing you to define the light boundaries in non-physical ways.
Light Decay
This filter can be added to all Arnold lights. This is where you will specify the attenuation ranges. All lights in Arnold use a physically-based falloff by default, but the light_decay filter can be used to adjust the falloff for artistic purposes.