class in UnityEngine
/
Implemented in:UnityEngine.CoreModule
Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.
CloseFor some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.
CloseLow-level graphics library.
Use this class to manipulate active transformation matrices,
issue rendering commands similar to OpenGL's immediate mode and do other low-level
graphics tasks. Note that in almost all cases using Graphics.RenderMesh or CommandBuffer
is more efficient than using immediate mode drawing.
GL immediate drawing functions use whatever is the "current material" set up right now (see Material.SetPass).
The material controls how the rendering is done (blending, textures, etc.), so unless you explicitly
set it to something before using GL draw functions, the material can happen to be anything.
Also, if you call any other drawing commands from inside GL drawing code, they can set
material to something else, so make sure it's under control as well.
GL drawing commands execute immediately. That means if you call them in Update(), they will be executed
before the camera is rendered (and the camera will most likely clear the screen, making the GL drawing
not visible).
The usual place to call GL drawing is most often in OnPostRender() from a script attached to a
camera, or inside an image effect function (OnRenderImage).
Note: The High Definition Render Pipeline (HDRP) and the Universal Render Pipeline (URP) do not support OnPostRender.
Instead, use RenderPipelineManager.endCameraRendering or RenderPipelineManager.endFrameRendering.
using UnityEngine;
public class ExampleClass : MonoBehaviour { // When added to an object, draws colored rays from the // transform position. public int lineCount = 100; public float radius = 3.0f;
static Material lineMaterial; static void CreateLineMaterial() { if (!lineMaterial) { // Unity has a built-in shader that is useful for drawing // simple colored things. Shader shader = Shader.Find("Hidden/Internal-Colored"); lineMaterial = new Material(shader); lineMaterial.hideFlags = HideFlags.HideAndDontSave; // Turn on alpha blending lineMaterial.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.SrcAlpha); lineMaterial.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.OneMinusSrcAlpha); // Turn backface culling off lineMaterial.SetInt("_Cull", (int)UnityEngine.Rendering.CullMode.Off); // Turn off depth writes lineMaterial.SetInt("_ZWrite", 0); } }
// Will be called after all regular rendering is done public void OnRenderObject() { CreateLineMaterial(); // Apply the line material lineMaterial.SetPass(0);
GL.PushMatrix(); // Set transformation matrix for drawing to // match our transform GL.MultMatrix(transform.localToWorldMatrix);
// Draw lines GL.Begin(GL.LINES); for (int i = 0; i < lineCount; ++i) { float a = i / (float)lineCount; float angle = a * Mathf.PI * 2; // Vertex colors change from red to green GL.Color(new Color(a, 1 - a, 0, 0.8F)); // One vertex at transform position GL.Vertex3(0, 0, 0); // Another vertex at edge of circle GL.Vertex3(Mathf.Cos(angle) * radius, Mathf.Sin(angle) * radius, 0); } GL.End(); GL.PopMatrix(); } }
Note: This class is almost always used when you need to draw a couple of lines or triangles, and don't want to deal with meshes. If you want to avoid surprises the usage pattern is this:
using UnityEngine; using System.Collections;
public class ExampleClass : MonoBehaviour { void OnPostRender() { // Set your materials GL.PushMatrix(); // yourMaterial.SetPass( ); // Draw your stuff GL.PopMatrix(); } }
Where at the "// Draw your stuff" you should do SetPass() on some material previously declared, which will be used for drawing. If you dont call SetPass, then you'll get basically a random material (whatever was used before) which is not good. So do it.
invertCulling | Select whether to invert the backface culling (true) or not (false). |
LINE_STRIP | Mode for Begin: draw line strip. |
LINES | Mode for Begin: draw lines. |
modelview | Gets or sets the modelview matrix. |
QUADS | Mode for Begin: draw quads. |
sRGBWrite | Controls whether Linear-to-sRGB color conversion is performed while rendering. |
TRIANGLE_STRIP | Mode for Begin: draw triangle strip. |
TRIANGLES | Mode for Begin: draw triangles. |
wireframe | Should rendering be done in wireframe? |
Begin | Begin drawing 3D primitives. |
Clear | Clear the current render buffer. |
ClearWithSkybox | Clear the current render buffer with camera's skybox. |
Color | Sets current vertex color. |
End | End drawing 3D primitives. |
Flush | Sends queued-up commands in the driver's command buffer to the GPU. |
GetGPUProjectionMatrix | Compute GPU projection matrix from camera's projection matrix. |
InvalidateState | Invalidate the internally cached render state. |
IssuePluginEvent | Send a user-defined event to a native code plugin. |
LoadIdentity | Load an identity into the current model and view matrices. |
LoadOrtho | Helper function to set up an orthograhic projection. |
LoadPixelMatrix | Setup a matrix for pixel-correct rendering. |
LoadProjectionMatrix | Load an arbitrary matrix to the current projection matrix. |
MultiTexCoord | Sets current texture coordinate (v.x,v.y,v.z) to the actual texture unit. |
MultiTexCoord2 | Sets current texture coordinate (x,y) for the actual texture unit. |
MultiTexCoord3 | Sets current texture coordinate (x,y,z) to the actual texture unit. |
MultMatrix | Sets the current model matrix to the one specified. |
PopMatrix | Restores the model, view and projection matrices off the top of the matrix stack. |
PushMatrix | Saves the model, view and projection matrices to the top of the matrix stack. |
RenderTargetBarrier | Resolves the render target for subsequent operations sampling from it. |
TexCoord | Sets current texture coordinate (v.x,v.y,v.z) for all texture units. |
TexCoord2 | Sets current texture coordinate (x,y) for all texture units. |
TexCoord3 | Sets current texture coordinate (x,y,z) for all texture units. |
Vertex | Submit a vertex. |
Vertex3 | Submit a vertex. |
Viewport | Set the rendering viewport. |
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.
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.