rc1 · March 7, 2017 16:21 · Mar 7, 2017
diff --git a/PointLightsImageEffect.cs b/PointLightsImageEffect.cs
@@ -0,0 +1,99 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+[ExecuteInEditMode]
+public class PointLightsImageEffect : MonoBehaviour {
+
+	private Camera _camera;
+	public Material EffectMaterial;
+
+	public Transform pointLight;
+
+	void OnEnable()
+	{
+		_camera = GetComponent<Camera>();
+		_camera.depthTextureMode = DepthTextureMode.DepthNormals;
+
+	}
+
+	[ImageEffectOpaque]
+	void OnRenderImage(RenderTexture src, RenderTexture dst)
+	{
+		// EffectMaterial.SetVector("_WorldSpaceScannerPos", ScannerOrigin.position);
+		// EffectMaterial.SetFloat("_ScanDistance", ScanDistance);
+
+		// Get the camera matrix to convert the view space normals to world normals
+		Matrix4x4 MV = _camera.cameraToWorldMatrix;
+		EffectMaterial.SetMatrix( "_CameraMV", MV);
+
+		// Update the point light
+		if ( pointLight != null ) {
+			EffectMaterial.SetVector( "_LightPosition", pointLight.position );
+		}
+
+		RaycastCornerBlit(src, dst, EffectMaterial);
+	}
+
+	void RaycastCornerBlit(RenderTexture source, RenderTexture dest, Material mat)
+	{
+		// Compute Frustum Corners
+		float camFar = _camera.farClipPlane;
+		float camFov = _camera.fieldOfView;
+		float camAspect = _camera.aspect;
+
+		float fovWHalf = camFov * 0.5f;
+
+		Vector3 toRight = _camera.transform.right * Mathf.Tan(fovWHalf * Mathf.Deg2Rad) * camAspect;
+		Vector3 toTop = _camera.transform.up * Mathf.Tan(fovWHalf * Mathf.Deg2Rad);
+
+		Vector3 topLeft = (_camera.transform.forward - toRight + toTop);
+		float camScale = topLeft.magnitude * camFar;
+
+		topLeft.Normalize();
+		topLeft *= camScale;
+
+		Vector3 topRight = (_camera.transform.forward + toRight + toTop);
+		topRight.Normalize();
+		topRight *= camScale;
+
+		Vector3 bottomRight = (_camera.transform.forward + toRight - toTop);
+		bottomRight.Normalize();
+		bottomRight *= camScale;
+
+		Vector3 bottomLeft = (_camera.transform.forward - toRight - toTop);
+		bottomLeft.Normalize();
+		bottomLeft *= camScale;
+
+		// Custom Blit, encoding Frustum Corners as additional Texture Coordinates
+		RenderTexture.active = dest;
+
+		mat.SetTexture("_MainTex", source);
+
+		GL.PushMatrix();
+		GL.LoadOrtho();
+
+		mat.SetPass(0);
+
+		GL.Begin(GL.QUADS);
+
+		GL.MultiTexCoord2(0, 0.0f, 0.0f);
+		GL.MultiTexCoord(1, bottomLeft);
+		GL.Vertex3(0.0f, 0.0f, 0.0f);
+
+		GL.MultiTexCoord2(0, 1.0f, 0.0f);
+		GL.MultiTexCoord(1, bottomRight);
+		GL.Vertex3(1.0f, 0.0f, 0.0f);
+
+		GL.MultiTexCoord2(0, 1.0f, 1.0f);
+		GL.MultiTexCoord(1, topRight);
+		GL.Vertex3(1.0f, 1.0f, 0.0f);
+
+		GL.MultiTexCoord2(0, 0.0f, 1.0f);
+		GL.MultiTexCoord(1, topLeft);
+		GL.Vertex3(0.0f, 1.0f, 0.0f);
+
+		GL.End();
+		GL.PopMatrix();
+	}
+}
diff --git a/PointLightsImageEffect.shader b/PointLightsImageEffect.shader
@@ -0,0 +1,113 @@
+Shader "PointLightsImageEffect"
+{
+	Properties
+	{
+		_MainTex ("Texture", 2D) = "white" {}
+		_LightColor ("Light Color", Color) = ( 1.0, 1.0, 1.0 )
+		_LightPosition ("Light Position", Vector) = ( 0.0, 0.0, 0.0 )
+		_LightRange ("Light Range", Float) = 1.0
+	}
+	SubShader
+	{
+		// No culling or depth
+		Cull Off ZWrite Off ZTest Always
+
+		Pass
+		{
+			CGPROGRAM
+			#pragma vertex vert
+			#pragma fragment frag
+
+			#include "UnityCG.cginc"
+
+			struct VertIn
+			{
+				float4 vertex : POSITION;
+				float2 uv : TEXCOORD0;
+				float4 ray : TEXCOORD1;
+			};
+
+			struct VertOut
+			{
+				float2 uv : TEXCOORD0;
+				float4 vertex : SV_POSITION;
+				float2 uv_depth : TEXCOORD1;
+				float4 interpolatedRay : TEXCOORD2;
+			};
+
+			VertOut vert (VertIn v)
+			{
+				VertOut o;
+				o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
+				o.uv = v.uv;
+				o.uv_depth = v.uv.xy;
+
+				#if UNITY_UV_STARTS_AT_TOP
+				if (_MainTex_TexelSize.y < 0)
+					o.uv.y = 1 - o.uv.y;
+				#endif	
+
+				o.interpolatedRay = v.ray;
+
+				return o;
+			}
+
+			sampler2D _MainTex;
+			// Provided by the camera
+			sampler2D_float _CameraDepthNormalsTexture;
+
+			// Provided by the material property
+			float4x4 _CameraMV;
+			float3 _LightPosition;
+			float4 _LightColor;
+			float _LightRange;
+
+			float3 lightDistanceNormalised ( float3 surfacePosition, float3 lightPosition, float lightRange ) {
+				float dis = distance( surfacePosition, lightPosition );
+				return 1.0 - clamp( dis / lightRange, 0.0, 1.0 );
+			}
+
+			fixed4 frag (VertOut i) : SV_Target
+			{
+
+				float4 finalColor;
+
+				// Get the surface color
+				float4 surfaceColor = tex2D(_MainTex, i.uv);
+
+				// Get the depth & normal
+				float rawDepth = 1.0;
+				float3 viewSpaceNormal;
+				DecodeDepthNormal( tex2D(_CameraDepthNormalsTexture, i.uv_depth.xy), rawDepth, viewSpaceNormal );
+
+				// Get the world position
+				float4 directionWorldSpace = rawDepth * i.interpolatedRay;
+				float3 surfaceWorldPosition = _WorldSpaceCameraPos + directionWorldSpace;
+
+				// Get the world normal
+				float3 surfaceWorldNormal = mul((float3x3)_CameraMV, viewSpaceNormal);
+
+				// Return the distance from the light
+				float distanceFromLight = clamp( 1.0 - distance( surfaceWorldPosition, _LightPosition ) / _LightRange, 0, 1 );
+
+				// Get the vector from the surface to the light
+				float3 surfaceToLight = _LightPosition - surfaceWorldPosition;
+
+				// Get the brightness of the surface (cosine of the angle of incidence). 1 means it is facing the light. 0 means it's not
+				float brightness = dot(surfaceWorldNormal, surfaceToLight) / (length(surfaceToLight) * length(surfaceWorldNormal));
+				brightness = clamp( brightness, 0, 1 );
+
+				// Get the intensity of the light based on the distance and the direction
+				float intensity = lerp( 0, brightness, distanceFromLight );
+
+				// Add the light to the surface color... there will be better ways
+				finalColor =  surfaceColor + ( _LightColor * intensity ); 
+
+				return finalColor;
+
+			}
+
+			ENDCG
+		}
+	}
+}