Module 3: What Are Render Groups

Broaden your understanding of how objects are rendered in Effect House! Use this tutorial to learn the concepts of render groups and camera render order.

This module is a conceptual overview that explains render groups and how they work in Effect House.

Module Objectives: By the end of this module, you should be comfortable with the following objectives:

Define what a render group is
Be familiar with the different types of render groups
Understand the difference between camera render order, render groups, and layers

note

This video was recorded using Effect House v2.2.0. Later versions of Effect House have features that may not be covered in this video.

What Is a Render Group?

In Effect House, a render group is a container in the Hierarchy panel that groups related objects together to optimize rendering.

Render groups are automatically added when you add an object to the Hierarchy panel. You can also add a render group by right-clicking in the Hierarchy panel and clicking Add Render Group.

If you add an Image object to the Hierarchy panel, you'll see that it automatically appears within the 2D Foreground Effects render group. You can rename a render group by right-clicking on it and then selecting Rename.

All objects added from the Object menu have an assigned render group that they are automatically categorized under. For example, if you add a Cube object, it automatically shows up in the existing General render group.

Each render group has its own camera. These cameras only render the objects within their respective render groups. You can also add multiple cameras to a group, and adjust their render order and layers to achieve different effects.

There are 9 render groups:

2D Background Effects
Generative Effects
Filter
Face Mask Effects
Face Shape Effects
General
AR Tracking
2D Foreground Effects
Post Effects

note

The AR Tracking and Filter render groups were added to Effect House after this video was created.

Order of Render Groups in the Hierarchy Panel

Render groups are listed in a specific order when they're added to the Hierarchy panel. This default ordering is meant to optimize your effect with TikTok's built-in effects. You can also choose whether to combine your effect with TikTok's built-in effects or overwrite them by clicking File in your computer's menu bar, going to Properties, and then changing the settings accordingly.

The placement of render groups in the Hierarchy panel determines the order in which they get rendered. Simply put, the render group at the top of the Hierarchy panel renders first, while the render group at the bottom renders last.

If you want to change the rendering order, simply drag the render group and drop it in your preferred placement. For example, if you want a Face Mask to render in front of an Image object, simply drag the Face Mask Effects render group beneath the 2D Foreground Effects render group, and see the changes reflected in the preview.

Camera Render Order

You can use multiple cameras to achieve different effects. Within an individual render group, you can use different cameras to render the scene onto different render textures.

When implementing multiple cameras, layers and render textures are important concepts to consider. Consider the following:

In a render group, there are objects. These objects exist on a layer.
The Camera views the layer, and then outputs the final image onto a render texture, which is simply a texture that shows what the camera is looking at.

An exception is made from this rule for light objects. A light object’s defined layer can be applied to all render groups. For example, if a light object is assigned to a certain layer, all objects within that layer will be affected by that light object, regardless of the render group they're in.

In Effect House, each camera has a Render Order property, which determines when a respective layer gets rendered. Cameras with a lower render order value render first, while cameras with higher render order values render last.

Render Order Example

Click the General render group's Camera object and then view the Inspector panel. The Camera is set to a Default Layer and has a Render Order of 0, meaning that it is the first camera to render.

If you add a Cube object to the Hierarchy panel, it is automatically assigned to the Default Layer.

Add another Camera object to the General render group. In the Inspector panel, go to the Camera component's Layer property and make sure only Layer 1 is selected. This Camera object has a Render Order value of 1, since it was added after the default Camera.

Next add a Sphere object to the Hierarchy panel. Set this Sphere object to appear only on Layer 1. Unlike cameras, objects can only be assigned to one layer.

The two cameras are responsible for different objects on different layers. Therefore, unchecking any one Camera in the Hierarchy panel will cause the object it's responsible for to disappear from the preview.

You can also modify the Camera objects' Render Order properties to change which object renders first.