---
title: "PxrRampLightFilter"
canonical: "https://rmanwiki-27.pixar.com/space/REN27/542229544/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://2639321b-a344-4479-bf63-9b8b39ed978e) | ![ramp_RampInterpolationCatmullRom.jpg](media://6034a6db-82b6-4004-82e4-eb6e07e3ec7e) | ![ramp_RampInterpolationConstant.jpg](media://02348064-7f30-487b-b418-011b923adc1d) | ![ramp_RampInterpolationLinear.jpg](media://26d77ed8-28a1-43be-96ea-544a460a4ea5) |


#### 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://bc16975f-b3a9-4df0-80d0-898491d2a390) | ![ramp_ColorRampInterpolationCatmullRom.jpg](media://6fa780a8-f81c-40bb-9f4e-56cfcf6f8466) | ![ramp_ColorRampInterpolationConstant.jpg](media://86847843-e7f9-40b7-83ae-ffbe74067b03) | ![ramp_ColorRampInterpolationLinear.jpg](media://ef25d967-1f31-4d8a-a6c8-3761c0684715) |


#### Combine Mode

Combine mode for PxrRampLightFilter is always multiplied.