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DebugDraw - Unity3D based debug drawing for programmers
// Remi Gillig - http://speps.fr - 2012 - Public domain
using System;
using System.Collections.Generic;
using UnityEngine;
public class DebugDraw
{
static Material material = new Material(
@"Shader ""Custom/DebugDraw"" {
Properties {
_Color (""Main Color"", Color) = (1,1,1,1)
}
SubShader {
Pass {
Color [_Color]
}
}
}");
static MeshCreator creator = new MeshCreator();
static Mesh solidSphere;
static Mesh solidCube;
static DebugDraw()
{
solidSphere = creator.CreateSphere(3);
solidCube = creator.CreateCube(0);
}
public static void DrawSphere(Vector3 position, float radius, Color color)
{
Matrix4x4 mat = Matrix4x4.TRS(position, Quaternion.identity, radius * 0.5f * Vector3.one);
MaterialPropertyBlock block = new MaterialPropertyBlock();
block.AddColor("_Color", color);
Graphics.DrawMesh(solidSphere, mat, material, 0, null, 0, block);
}
public static void DrawCube(Vector3 position, Quaternion rotation, float size, Color color)
{
Matrix4x4 mat = Matrix4x4.TRS(position, rotation, size * Vector3.one);
MaterialPropertyBlock block = new MaterialPropertyBlock();
block.AddColor("_Color", color);
Graphics.DrawMesh(solidCube, mat, material, 0, null, 0, block);
}
#region MeshCreator
public class MeshCreator
{
private List<Vector3> positions;
private List<Vector2> uvs;
private int index;
private Dictionary<Int64, int> middlePointIndexCache;
// add vertex to mesh, fix position to be on unit sphere, return index
private int addVertex(Vector3 p, Vector2 uv)
{
positions.Add(p);
uvs.Add(uv);
return index++;
}
// return index of point in the middle of p1 and p2
private int getMiddlePoint(int p1, int p2)
{
// first check if we have it already
bool firstIsSmaller = p1 < p2;
Int64 smallerIndex = firstIsSmaller ? p1 : p2;
Int64 greaterIndex = firstIsSmaller ? p2 : p1;
Int64 key = (smallerIndex << 32) + greaterIndex;
int ret;
if (this.middlePointIndexCache.TryGetValue(key, out ret))
{
return ret;
}
// not in cache, calculate it
Vector3 point1 = this.positions[p1];
Vector3 point2 = this.positions[p2];
Vector3 middle = new Vector3(
(point1.x + point2.x) / 2.0f,
(point1.y + point2.y) / 2.0f,
(point1.z + point2.z) / 2.0f);
Vector2 uv1 = this.uvs[p1];
Vector2 uv2 = this.uvs[p2];
Vector2 uvmid = new Vector2(
(uv1.x + uv2.x) / 2.0f,
(uv1.y + uv2.y) / 2.0f);
// add vertex makes sure point is on unit sphere
int i = addVertex(middle, uvmid);
// store it, return index
this.middlePointIndexCache.Add(key, i);
return i;
}
public Mesh CreateCube(int subdivisions)
{
positions = new List<Vector3>();
uvs = new List<Vector2>();
middlePointIndexCache = new Dictionary<long, int>();
index = 0;
var indices = new List<int>();
// front
addVertex(new Vector3(-1, -1, 1), new Vector2(1, 0));
addVertex(new Vector3(-1, 1, 1), new Vector2(1, 1));
addVertex(new Vector3(1, 1, 1), new Vector2(0, 1));
addVertex(new Vector3(1, -1, 1), new Vector2(0, 0));
indices.Add(0); indices.Add(3); indices.Add(2);
indices.Add(2); indices.Add(1); indices.Add(0);
// right
addVertex(new Vector3(1, -1, 1), new Vector2(1, 0));
addVertex(new Vector3(1, 1, 1), new Vector2(1, 1));
addVertex(new Vector3(1, 1, -1), new Vector2(0, 1));
addVertex(new Vector3(1, -1, -1), new Vector2(0, 0));
indices.Add(4); indices.Add(7); indices.Add(6);
indices.Add(6); indices.Add(5); indices.Add(4);
// back
addVertex(new Vector3(1, -1, -1), new Vector2(1, 0));
addVertex(new Vector3(1, 1, -1), new Vector2(1, 1));
addVertex(new Vector3(-1, 1, -1), new Vector2(0, 1));
addVertex(new Vector3(-1, -1, -1), new Vector2(0, 0));
indices.Add(8); indices.Add(11); indices.Add(10);
indices.Add(10); indices.Add(9); indices.Add(8);
// left
addVertex(new Vector3(-1, -1, -1), new Vector2(1, 0));
addVertex(new Vector3(-1, 1, -1), new Vector2(1, 1));
addVertex(new Vector3(-1, 1, 1), new Vector2(0, 1));
addVertex(new Vector3(-1, -1, 1), new Vector2(0, 0));
indices.Add(12); indices.Add(15); indices.Add(14);
indices.Add(14); indices.Add(13); indices.Add(12);
// top
addVertex(new Vector3(1, 1, 1), new Vector2(0, 0));
addVertex(new Vector3(1, 1, -1), new Vector2(0, 1));
addVertex(new Vector3(-1, 1, -1), new Vector2(1, 1));
addVertex(new Vector3(-1, 1, 1), new Vector2(1, 0));
indices.Add(16); indices.Add(17); indices.Add(18);
indices.Add(18); indices.Add(19); indices.Add(16);
// bottom
addVertex(new Vector3(1, -1, 1), new Vector2(1, 0));
addVertex(new Vector3(1, -1, -1), new Vector2(1, 1));
addVertex(new Vector3(-1, -1, -1), new Vector2(0, 1));
addVertex(new Vector3(-1, -1, 1), new Vector2(0, 0));
indices.Add(21); indices.Add(20); indices.Add(23);
indices.Add(23); indices.Add(22); indices.Add(21);
for (int i = 0; i < subdivisions; i++)
{
var indices2 = new List<int>();
for (int idx = 0; idx < indices.Count; idx += 3)
{
// replace triangle by 4 triangles
int a = getMiddlePoint(indices[idx + 0], indices[idx + 1]);
int b = getMiddlePoint(indices[idx + 1], indices[idx + 2]);
int c = getMiddlePoint(indices[idx + 2], indices[idx + 0]);
indices2.Add(indices[idx + 0]); indices2.Add(a); indices2.Add(c);
indices2.Add(indices[idx + 1]); indices2.Add(b); indices2.Add(a);
indices2.Add(indices[idx + 2]); indices2.Add(c); indices2.Add(b);
indices2.Add(a); indices2.Add(b); indices2.Add(c);
}
indices = indices2;
}
// done, create the mesh
var mesh = new Mesh();
mesh.vertices = positions.ToArray();
mesh.triangles = indices.ToArray();
mesh.uv = uvs.ToArray();
mesh.RecalculateNormals();
var colors = new Color[mesh.vertexCount];
for (int i = 0; i < colors.Length; i++)
colors[i] = new Color(1.0f, 1.0f, 1.0f);
mesh.colors = colors;
RecalculateTangents(mesh);
return mesh;
}
public Mesh CreateSphere(int subdivisions)
{
var sphere = CreateCube(subdivisions);
var vertices = new List<Vector3>(sphere.vertices);
for (int i = 0; i < vertices.Count; i++)
vertices[i] = vertices[i].normalized;
sphere.vertices = vertices.ToArray();
sphere.RecalculateNormals();
RecalculateTangents(sphere);
return sphere;
}
// Lengyel, Eric. “Computing Tangent Space Basis Vectors for an Arbitrary Mesh”.
// Terathon Software 3D Graphics Library, 2001. http://www.terathon.com/code/tangent.html
public static void RecalculateTangents(Mesh mesh)
{
var tan1 = new Vector3[mesh.vertexCount];
var tan2 = new Vector3[mesh.vertexCount];
for (int a = 0; a < mesh.triangles.Length; a += 3)
{
int i1 = mesh.triangles[a + 0];
int i2 = mesh.triangles[a + 1];
int i3 = mesh.triangles[a + 2];
Vector3 v1 = mesh.vertices[i1];
Vector3 v2 = mesh.vertices[i2];
Vector3 v3 = mesh.vertices[i3];
Vector2 w1 = mesh.uv[i1];
Vector2 w2 = mesh.uv[i2];
Vector2 w3 = mesh.uv[i3];
float x1 = v2.x - v1.x;
float x2 = v3.x - v1.x;
float y1 = v2.y - v1.y;
float y2 = v3.y - v1.y;
float z1 = v2.z - v1.z;
float z2 = v3.z - v1.z;
float s1 = w2.x - w1.x;
float s2 = w3.x - w1.x;
float t1 = w2.y - w1.y;
float t2 = w3.y - w1.y;
float r = 1.0F / (s1 * t2 - s2 * t1);
var sdir = new Vector3((t2 * x1 - t1 * x2) * r, (t2 * y1 - t1 * y2) * r,
(t2 * z1 - t1 * z2) * r);
var tdir = new Vector3((s1 * x2 - s2 * x1) * r, (s1 * y2 - s2 * y1) * r,
(s1 * z2 - s2 * z1) * r);
tan1[i1] += sdir;
tan1[i2] += sdir;
tan1[i3] += sdir;
tan2[i1] += tdir;
tan2[i2] += tdir;
tan2[i3] += tdir;
}
var tangents = new Vector4[mesh.vertexCount];
for (long a = 0; a < mesh.vertexCount; a++)
{
Vector3 n = mesh.normals[a];
Vector3 t = tan1[a];
// Gram-Schmidt orthogonalize
tangents[a] = t - n * Vector3.Dot(n, t);
tangents[a].Normalize();
// Calculate handedness
tangents[a].w = (Vector3.Dot(Vector3.Cross(n, t), tan2[a]) < 0.0f) ? -1.0f : 1.0f;
}
mesh.tangents = tangents;
}
#endregion
}
}
@ewersp

Hey man, thanks for your library; it's great! (clever way of generating the sphere by the way) I've added transparency support in the shader for anyone else who might like it.

static Material material = new Material(
    @"Shader ""Custom/DebugDraw"" {
    Properties {
        _Color (""Main Color"", Color) = (1,1,1,1)
    }
    SubShader {
        ZWrite Off
        Blend SrcAlpha OneMinusSrcAlpha
        Fog { Mode off }
        Tags {""Queue"" = ""Transparent""}
        Pass {
            Color[_Color]
        }
    }
}");

I've also added support for cylinders.

public static void DrawCylinder(Vector3 position, Quaternion rotation, Vector3 scale, Color color)
{
    Matrix4x4 mat = Matrix4x4.TRS(position, rotation, scale);
    MaterialPropertyBlock block = new MaterialPropertyBlock();
    block.AddColor("_Color", color);
    Graphics.DrawMesh(solidCylinder, mat, material, 0, null, 0, block);
}

public Mesh CreateCylinder(int subdivisions)
{
    var cylinder = CreateCube(subdivisions);
    var vertices = new List<Vector3>(cylinder.vertices);

    for (int i = 0; i < vertices.Count; i++) 
    {
        Vector3 pos = new Vector3(vertices[i].x, 0.0f, vertices[i].z).normalized;
        pos.y = vertices[i].y;
        vertices[i] = pos;
    }

    cylinder.vertices = vertices.ToArray();
    cylinder.RecalculateNormals();
    RecalculateTangents(cylinder);

    return cylinder;
}
@insominx

With Unity 5, color no longer appears to work. Any ideas?

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