---
title: "PxrRampLightFilter"
canonical: "https://rmanwiki-25.pixar.com/space/REN25/20416240/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://01e5e3ec-06e2-439d-843a-376ec79bc258) | ![ramp_RampInterpolationCatmullRom.jpg](media://460d1bc5-253c-4075-87e9-230104faa2eb) | ![ramp_RampInterpolationConstant.jpg](media://f4348cff-6865-408b-8a02-d53200af6469) | ![ramp_RampInterpolationLinear.jpg](media://f5d4c592-6f2e-4745-aff8-5838d8c1549e) |


#### 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://97cd43f3-29ab-4932-9304-16e215bb4c73) | ![ramp_ColorRampInterpolationCatmullRom.jpg](media://88b45d5a-0318-478a-9e88-730a026d8d3c) | ![ramp_ColorRampInterpolationConstant.jpg](media://5b1d1b64-be29-4764-951d-539b81e5fbeb) | ![ramp_ColorRampInterpolationLinear.jpg](media://20122ca0-ad37-47c3-b247-e2e2847304c3) |


#### Combine Mode

Combine mode for PxrRampLightFilter is always multiplied.