---
title: "PxrRampLightFilter"
canonical: "https://rmanwiki-26.pixar.com/space/REN26/19661759/PxrRampLightFilter"
format: markdown
---
PxrRampLightFilter uses a ramp to control the light. It may also be useful to artificially and artistically control light decay.


---


### Parameters


#### Ramp Direction

**Ramp Type**

Specify in which direction the ramp is applied.

- distToLight(0) - distance to the light.
- linear(1) - linear ramp.
- spherical(2) - spherical ramp.
- radial(3) - radial ramp.


**Begin Distance**

Distance where the ramp starts.


**End Distance**

Distance where the ramp ends.


#### Ramp

**Ramp**

Define the number of knots.


**Ramp Knots**

An array of knot values.


**Ramp Floats**

An array of float values.


**Ramp Interpolation**

Type of ramp interpolation:

- linear
- catmull-rom
- bspline
- constant

|  |  |  |  |
| --- | --- | --- | --- |
| ![ramp_RampInterpolationBspline.jpg](media://c47c0f13-3796-403c-b780-189758de4081) | ![ramp_RampInterpolationCatmullRom.jpg](media://6c71e451-a898-4730-a839-eabe29a3d60a) | ![ramp_RampInterpolationConstant.jpg](media://353f684b-0ff6-4fc5-a92c-1f8534c1b8f2) | ![ramp_RampInterpolationLinear.jpg](media://2b301f81-cbea-45e3-800d-877a15f5add0) |


#### Multiplier

**Density**

Controls the strength of the projected effect.


**Invert**

Specify whether to invert the projected texture before it is applied.


**Intensity**

Global Multiplier for both the diffuse and specular contribution below.


**Diffuse**

Multiplier of this light filter result for the diffuse contribution.


**Specular**

Multiplier of this light filter result for the specular contribution.


#### Color Ramp

**Color Ramp**

Define the number of knots.


**Color Ramp Knots**

An array of knot values.


**Ramp Colors**

An array of color values.


**Color Ramp Interpolation**

Type of color ramp interpolation:

- linear
- catmull-rom
- bspline
- constant

|  |  |  |  |
| --- | --- | --- | --- |
| ![ramp_ColorRampInterpolationBspline.jpg](media://6f746548-541d-4c13-9b25-a9aaa884ffff) | ![ramp_ColorRampInterpolationCatmullRom.jpg](media://269e7335-487e-40bb-8301-f6b2595f5774) | ![ramp_ColorRampInterpolationConstant.jpg](media://1c6589d8-676c-42a4-bdb1-86f587132d90) | ![ramp_ColorRampInterpolationLinear.jpg](media://36b11e29-6a03-492b-9f90-10600ffa3fda) |


#### Combine Mode

Combine mode for PxrRampLightFilter is always multiplied.