# Scenes

## Overview

Scenes are critical components in a visual configuration

* They help bring all the visuals together with Lighting, Cameras, and Post-Processing effects
* The Scene is the only place where we can define the active camera used by the player
* Scenes cannot be nested, as Models can - only one scene can be active at a time
* They can be referenced directly by both Catalog Items as well as Stages
* This is where we can set the background image/color/transparency for the player
* This is also where we can control the environment lighting for the 3D player with HDR images

## WebGl Post-Effects

### Tonemapping

An overall adjustment of the dynamic range, colors, and contrast of the 3D player images

### SAO Pass

Screen Space Ambient Occlusion - add shadows to crevices or nearby surfaces points

### Opacity Mask

Use an uploaded video or image to mask out the player visuals

### Sketch Pass

Tansform the player visuals with added outlines for meshes and polygon edges

### [Bloom Pass](/platform-documentation/catalog-2.0-docs/project-data/operators/posteffects-operators/bloom-pass.md)

Add a glowing bloom to the player visuals, based on luminosity thresholds

{% hint style="info" %}
It is important to note that all post effects affect the performance of the player in direct proportion to the size of the player embed

* The larger the player, the slower it gets
  {% endhint %}


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