54 lines
2.0 KiB
C#

using UnityEngine;
// This class implements simple ghosting type Motion Blur.
// If Extra Blur is selected, the scene will allways be a little blurred,
// as it is scaled to a smaller resolution.
// The effect works by accumulating the previous frames in an accumulation
// texture.
[AddComponentMenu("Image Effects/Motion Blur")]
public class MotionBlur : ImageEffectBase
{
public float blurAmount = 0.8f;
public bool extraBlur = false;
private RenderTexture accumTexture;
protected new void OnDisable()
{
base.OnDisable();
DestroyImmediate(accumTexture);
}
// Called by camera to apply image effect
void OnRenderImage(RenderTexture source, RenderTexture destination)
{
// Create the accumulation texture
if (accumTexture == null || accumTexture.width != source.width || accumTexture.height != source.height)
{
DestroyImmediate(accumTexture);
accumTexture = new RenderTexture(source.width, source.height, 0);
accumTexture.hideFlags = HideFlags.HideAndDontSave;
ImageEffects.Blit(source, accumTexture);
}
// If Extra Blur is selected, downscale the texture to 4x4 smaller resolution.
if (extraBlur)
{
RenderTexture blurbuffer = RenderTexture.GetTemporary(source.width / 4, source.height / 4, 0);
ImageEffects.Blit(accumTexture, blurbuffer);
ImageEffects.Blit(blurbuffer, accumTexture);
RenderTexture.ReleaseTemporary(blurbuffer);
}
// Clamp the motion blur variable, so it can never leave permanent trails in the image
blurAmount = Mathf.Clamp(blurAmount, 0.0f, 0.92f);
// Setup the texture and floating point values in the shader
material.SetTexture("_MainTex", accumTexture);
material.SetFloat("_AccumOrig", 1.0F - blurAmount);
// Render the image using the motion blur shader
Graphics.Blit(source, accumTexture, material);
Graphics.Blit(accumTexture, destination);
}
}