Layers in Unity define which GameObjects can interact with different features and one another. They are most commonly used by CamerasA component which creates an image of a particular viewpoint in your scene. The output is either drawn to the screen or captured as a texture. More info
See in Glossary to render only a part of the sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary, and by Lights to illuminate only parts of the scene. But they can also be used by raycasting to selectively ignore collidersAn invisible shape that is used to handle physical collisions for an object. A collider doesn’t need to be exactly the same shape as the object’s mesh - a rough approximation is often more efficient and indistinguishable in gameplay. More info
See in Glossary or to create collisionsA collision occurs when the physics engine detects that the colliders of two GameObjects make contact or overlap, when at least one has a Rigidbody component and is in motion. More info
See in Glossary.
The first step is to create a new layer, which we can then assign to a GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary. To create a new layer, open the Tags and Layers window (main menu: Edit > Project Settings, then select the Tags and Layers category).
We create a new layer in one of the empty User Layers. We choose layer 8.
Now that you have created a new layer, you can assign the layer to one or more GameObjects.
Each GameObject can only be assigned one layer.
In the Tags and Layers window, the Player layer is assigned to layer 8.
Using the camera’s culling maskAllows you to include or omit objects to be rendered by a Camera, by Layer.
See in Glossary, you can selectively render objects which are in one particular layer.
To do this, select the camera that should selectively render objects.
Modify the culling mask by checking or unchecking layers in the culling mask property.
Be aware that UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
See in Glossary elements aren’t culled. Screen space canvas children do not respect the camera’s culling mask.
Using layers you can cast rays and ignore colliders in specific layers. For example you might want to cast a ray only against the player layer and ignore all other colliders.
The Physics.Raycast function takes a bitmask, where each bit determines if a layer will be ignored or not. If all bits in the layerMask are on, we will collide against all colliders. If the layerMask = 0, we will never find any collisions with the ray.
int layerMask = 1 << 8;
// Does the ray intersect any objects which are in the player layer.
if (Physics.Raycast(transform.position, Vector3.forward, Mathf.Infinity, layerMask))
{
Debug.Log("The ray hit the player");
}
In the real world you want to do the inverse of that however. We want to cast a ray against all colliders except those in the Player layer.
void Update ()
{
// Bit shift the index of the layer (8) to get a bit mask
int layerMask = 1 << 8;
// This would cast rays only against colliders in layer 8.
// But instead we want to collide against everything except layer 8. The ~ operator does this, it inverts a bitmask.
layerMask = ~layerMask;
RaycastHit hit;
// Does the ray intersect any objects excluding the player layer
if (Physics.Raycast(transform.position, transform.TransformDirection (Vector3.forward), out hit, Mathf.Infinity, layerMask))
{
Debug.DrawRay(transform.position, transform.TransformDirection (Vector3.forward) * hit.distance, Color.yellow);
Debug.Log("Did Hit");
}
else
{
Debug.DrawRay(transform.position, transform.TransformDirection (Vector3.forward) *1000, Color.white);
Debug.Log("Did not Hit");
}
}
When you don’t pass a layerMask to the Raycast function, it will only ignore colliders that use the IgnoreRaycast layer. This is the easiest way to ignore some colliders when casting a ray.
2017–05–08 Page amended
Culling mask information updated in Unity 2017.1
When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.
More information
These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
These cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising. Some 3rd party video providers do not allow video views without targeting cookies. If you are experiencing difficulty viewing a video, you will need to set your cookie preferences for targeting to yes if you wish to view videos from these providers. Unity does not control this.
These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information.