Basic volume texture sphere tracer.

Author: przemyslawzaworski

Diff for: volume_texture.shader

@@ -0,0 +1,52 @@
+//Add quad to Main Camera, then add volume_texture.cs to quad and material with shader (both to script and Mesh Renderer). 
+//Set quad position to (0,0,0.4). Play.
+
+Shader "Volume Texture"
+{
+	Properties 
+	{
+		[HideInInspector]
+		volume ("Texture 3D", 3D) = "black" {}
+	}
+	Subshader
+	{	
+		Pass
+		{
+			CGPROGRAM
+			#pragma vertex vertex_shader
+			#pragma fragment pixel_shader
+			#pragma target 3.0
+
+			sampler3D volume;
+			
+			struct structure
+			{
+				float4 screen_vertex : SV_POSITION;
+				float3 world_vertex : TEXCOORD0;
+			};
+
+			structure vertex_shader (float4 vertex:POSITION) 
+			{
+				structure vs;
+				vs.screen_vertex = UnityObjectToClipPos (vertex);
+				vs.world_vertex = mul (unity_ObjectToWorld, vertex);
+				return vs;
+			}
+
+			float4 pixel_shader (structure ps) : SV_TARGET
+			{
+				float3 ro = ps.world_vertex;
+				float3 rd = normalize(ps.world_vertex - _WorldSpaceCameraPos.xyz);  
+				float4 s = float4(0.0,0.0,0.0,0.0);
+				for (float t = 1.0; t < 32.0; t++) 
+				{
+					ro+=rd*t;
+					s+=tex3Dlod(volume,float4(ro*.002,0))*.06;
+					if (s.w >= 1.0) break;
+				}    
+				return lerp(float4(0.0,0.0,0.0,0.0),s,s.w);				
+			}
+			ENDCG
+		}
+	}
+}