---
title: "44 - Layer Maps > Size Subgroup"
url: "https://help.maxon.net/rg/en-us/Content/html/44-Trapcode-Particular-layer-maps_size.html"
section_path: "Particles and 3D > Trapcode Particular > 44 - Layer Maps > Size Subgroup"
description: "The Size group lets you change the size of system particles by using a source layer's luminance values. Black regions of the layer image will have a …"
---

# 44 - Layer Maps > Size Subgroup

Particular

## Layer Maps > Size Subgroup

The Size group lets you change the size of system particles by using a source layer's luminance values. Black regions of the layer image will have a particle size of 0, which creates holes in the field. White regions have their particle size set to the maximum value of the Particle group > Size control.

![Image: TC_Particular_LayerGroup10.png](https://help.maxon.net/rg/en-us/Content/Resources/Images/TC_Particular_LayerGroup10.png)

![Image: TC_Particular_LayerGroup11.png](https://help.maxon.net/rg/en-us/Content/Resources/Images/TC_Particular_LayerGroup11.png)\
*A layer with a gradient ramp (left), a particle field with Particle Size set to 8 (middle), and the gradient ramp applied as the Size map with Map Over set to XY (right).*