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Camera.onPreRender

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public static Camera.CameraCallback onPreRender;

Description

Event that is fired before any camera starts rendering.

Note that when onPreRender is called, the camera's render target is not set up yet, and the depth texture(s) are not rendered yet either. If you want to do something later on (when the render target is already set), try using a CommandBuffer.

using UnityEngine;
public class ExampleClass : MonoBehaviour
{
    // callback to be called before any camera starts rendering
    public void MyPreRender(Camera cam)
    {
        Debug.Log("PreRender " + gameObject.name + " from camera " + cam.gameObject.name);
    }

public void OnEnable() { // register the callback when enabling object Camera.onPreRender += MyPreRender; }

public void OnDisable() { // remove the callback when disabling object Camera.onPreRender -= MyPreRender; } }