How do I use PSIZE in a Unity 4.5.4 shader?

Question

I'm told that Unity overhauled the shader compile system in version 4.5. I am unable to get any examples of a shader that sets the size of vertices to work in Unity 4.5.

I am trying to build a point cloud editor that will allow me to scale the visible point size as the user scales a model. I have seen several posts claiming this approach works but they are all a couple years old..

Here is the shader I have been trying:

 Shader "Custom/VertexColor" {
     SubShader {
     Pass {
         Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
         LOD 200
               
                  
         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag
         #include "UnityCG.cginc"
   
         struct VertexInput {
             float4 v : POSITION;
             float4 color: COLOR;
         };
          
         struct VertexOutput {
             float4 pos : SV_POSITION;
             float4 col : COLOR;
             float4 size : PSIZE;
         };
          
         VertexOutput vert(VertexInput v) {
          
             VertexOutput o;
             o.pos = mul(UNITY_MATRIX_MVP, v.v);
             o.col = v.color;
             o.size = 10.0;
             return o;
         }
          
         float4 frag(VertexOutput o) : COLOR {
             return o.col;
         }
  
         ENDCG
         } 
     }
  
 }

Answer 1

The only way I've been able to get PSIZE to work is by forcing OpenGL. There may be a workaround for Direct3D but this might get you started.

First, run Unity with OpenGL like so:

 "C:\Program Files (x86)\Unity\Editor\Unity.exe" -force-opengl

Attach the following script to your main camera. This enables point size in OpenGL. (Source)

 #if UNITY_STANDALONE
 #define IMPORT_GLENABLE
 #endif
  
 using UnityEngine;
 using System;
 using System.Collections;
 using System.Runtime.InteropServices;
  
 public class EnablePointSize : MonoBehaviour 
 {
     const UInt32 GL_VERTEX_PROGRAM_POINT_SIZE = 0x8642;
     const UInt32 GL_POINT_SMOOTH = 0x0B10;
      
     const string LibGLPath =
         #if UNITY_STANDALONE_WIN
         "opengl32.dll";
     #elif UNITY_STANDALONE_OSX
     "/System/Library/Frameworks/OpenGL.framework/OpenGL";
     #elif UNITY_STANDALONE_LINUX
     "libGL";  // Untested on Linux, this may not be correct
     #else
     null;   // OpenGL ES platforms don't require this feature
     #endif
      
     #if IMPORT_GLENABLE
     [DllImport(LibGLPath)]
     public static extern void glEnable(UInt32 cap);
      
     private bool mIsOpenGL;
      
     void Start()
     {
         mIsOpenGL = SystemInfo.graphicsDeviceVersion.Contains("OpenGL");
     }
      
     void OnPreRender()
     {
         if (mIsOpenGL)
             glEnable(GL_VERTEX_PROGRAM_POINT_SIZE);
             glEnable(GL_POINT_SMOOTH);
     }
     #endif
 }

Attach the following script to a GameObject to create a point mesh. (Source)

 using UnityEngine;
 using System.Collections;
  
  
 [RequireComponent(typeof(MeshFilter), typeof(MeshRenderer))]
 public class PointCloud : MonoBehaviour {
  
     private Mesh mesh;
     int numPoints = 60000;
  
     // Use this for initialization
     void Start () {
         mesh = new Mesh();
  
         GetComponent<MeshFilter>().mesh = mesh;
         CreateMesh();
     }
  
     void CreateMesh() {
         Vector3[] points = new Vector3[numPoints];
         int[] indecies = new int[numPoints];
         Color[] colors = new Color[numPoints];
         for(int i=0;i<points.Length;++i) {
             points[i] = new Vector3(Random.Range(-10,10), Random.Range (-10,10), Random.Range (-10,10));
             indecies[i] = i;
             colors[i] = new Color(Random.Range(0.0f,1.0f),Random.Range (0.0f,1.0f),Random.Range(0.0f,1.0f),1.0f);
         }
  
         mesh.vertices = points;
         mesh.colors = colors;
         mesh.SetIndices(indecies, MeshTopology.Points,0);
  
     }
 }

Attach your shader using PSIZE to that game object as a Material.

Now you should have a point cloud.

How do I use PSIZE in a Unity 4.5.4 shader?

1 Reply

Your answer

Welcome to Unity Answers

Follow this Question

Related Questions