/// <summary>
/// Write the contents of a single obj & mtl from a set of models.
/// </summary>
/// <param name="name"></param>
/// <param name="models"></param>
/// <param name="objContents"></param>
/// <param name="mtlContents"></param>
/// <param name="textures"></param>
/// <param name="options"></param>
/// <returns></returns>
public static bool Export(string name, IEnumerable <Model> models, out string objContents, out string mtlContents, out List <string> textures, ObjOptions options = null)
{
if (models == null || models.Count() < 1)
{
objContents = null;
mtlContents = null;
textures = null;
return(false);
}
Dictionary <Material, string> materialMap = null;
if (options == null)
{
options = new ObjOptions();
}
mtlContents = WriteMtlContents(models, options, out materialMap, out textures);
objContents = WriteObjContents(name, models, materialMap, options);
return(true);
}
/// <summary>
/// Write the material file for an OBJ. This function handles making the list of Materials unique & ensuring unique names for each group. Material to named mtl group are stored in materialMap.
/// </summary>
/// <param name="models"></param>
/// <param name="options"></param>
/// <param name="materialMap"></param>
/// <param name="textures"></param>
/// <returns></returns>
static string WriteMtlContents(IEnumerable <Model> models, ObjOptions options, out Dictionary <Material, string> materialMap, out List <string> textures)
{
materialMap = new Dictionary <Material, string>();
foreach (Model model in models)
{
for (int i = 0, c = model.submeshCount; i < c; i++)
{
Material material = model.materials[i];
if (material == null)
{
continue;
}
if (!materialMap.ContainsKey(material))
{
string escapedName = material.name.Replace(" ", "_");
string name = escapedName;
int nameIncrement = 1;
while (materialMap.Any(x => x.Value.Equals(name)))
{
name = string.Format("{0}_{1}", escapedName, nameIncrement++);
}
materialMap.Add(material, name);
}
}
}
StringBuilder sb = new StringBuilder();
textures = new List <string>();
foreach (KeyValuePair <Material, string> group in materialMap)
{
Material mat = group.Key;
sb.AppendLine(string.Format("newmtl {0}", group.Value));
// Texture maps
if (mat.shader != null)
{
foreach (var texPropertyName in mat.GetTexturePropertyNames())
{
Texture texture = mat.GetTexture(texPropertyName);
string textureName = null;
#if UNITY_EDITOR
string path = texture != null?UnityEditor.AssetDatabase.GetAssetPath(texture) : null;
if (!string.IsNullOrEmpty(path))
{
if (options.copyTextures)
{
textures.Add(path);
}
// remove "Assets/" from start of path
path = path.Substring(7, path.Length - 7);
textureName = options.copyTextures ? Path.GetFileName(path) : string.Format("{0}/{1}", Application.dataPath, path);
}
else
#endif
if (texture)
{
textureName = texture.name;
}
if (!string.IsNullOrEmpty(textureName))
{
string mtlKey;
if (s_TextureMapKeys.TryGetValue(texPropertyName, out mtlKey))
{
Vector2 offset = mat.GetTextureOffset(texPropertyName);
Vector2 scale = mat.GetTextureScale(texPropertyName);
if (options.textureOffsetScale)
{
sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "{0} -o {1} {2} -s {3} {4} {5}", mtlKey, offset.x, offset.y, scale.x, scale.y, textureName));
}
else
{
sb.AppendLine(string.Format("{0} {1}", mtlKey, textureName));
}
}
}
}
}
if (mat.HasProperty("_Color"))
{
Color color = mat.color;
// Diffuse
sb.AppendLine(string.Format("Kd {0}", string.Format(CultureInfo.InvariantCulture, "{0} {1} {2}", color.r, color.g, color.b)));
// Transparency
sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "d {0}", color.a));
}
else
{
sb.AppendLine("Kd 1.0 1.0 1.0");
sb.AppendLine("d 1.0");
}
sb.AppendLine();
}
return(sb.ToString());
}
static string WriteObjContents(string name, IEnumerable <Model> models, Dictionary <Material, string> materialMap, ObjOptions options)
{
// Empty names in OBJ groups can crash some 3d programs (meshlab)
if (string.IsNullOrEmpty(name))
{
name = "default";
}
StringBuilder sb = new StringBuilder();
sb.AppendLine("# ARFace.ObjExporter");
sb.AppendLine(string.Format("# {0}", System.DateTime.Now));
sb.AppendLine();
sb.AppendLine(string.Format("mtllib ./{0}.mtl", name.Replace(" ", "_")));
sb.AppendLine(string.Format("o {0}", name));
sb.AppendLine();
// obj orders indices 1 indexed
int positionOffset = 1;
int normalOffset = 1;
int textureOffset = 1;
bool reverseWinding = options.handedness == ObjOptions.Handedness.Right;
float handedness = options.handedness == ObjOptions.Handedness.Left ? 1f : -1f;
foreach (Model model in models)
{
int subMeshCount = model.submeshCount;
Matrix4x4 matrix = options.applyTransforms ? model.matrix : Matrix4x4.identity;
int vertexCount = model.vertexCount;
Vector3[] positions = model.vertices;
Color[] colors = model.mesh.colors;
Vector2[] textures0 = model.mesh.uv;
Vector3[] normals = model.mesh.normals;
if (colors != null && colors.Length == 0)
{
colors = null;
}
if (textures0 != null && textures0.Length == 0)
{
textures0 = null;
}
if (normals != null && normals.Length == 0)
{
normals = null;
}
// Can skip this entirely if handedness matches Unity & not applying transforms.
// matrix is set to identity if not applying transforms.
if (options.handedness != ObjOptions.Handedness.Left || options.applyTransforms)
{
for (int i = 0; i < vertexCount; i++)
{
if (positions != null)
{
positions[i] = matrix.MultiplyPoint3x4(positions[i]);
positions[i].x *= handedness;
}
if (normals != null)
{
normals[i] = matrix.MultiplyVector(normals[i]);
normals[i].x *= handedness;
}
}
}
sb.AppendLine(string.Format("g {0}", model.name));
Dictionary <int, int> positionIndexMap;
var positionCount = AppendPositions(sb, positions, colors, true, options.vertexColors, out positionIndexMap);
sb.AppendLine();
Dictionary <int, int> textureIndexMap;
var textureCount = AppendArrayVec2(sb, textures0, "vt", true, out textureIndexMap);
sb.AppendLine();
Dictionary <int, int> normalIndexMap;
var normalCount = AppendArrayVec3(sb, normals, "vn", true, out normalIndexMap);
sb.AppendLine();
// Material assignment
for (int submeshIndex = 0; submeshIndex < subMeshCount; submeshIndex++)
{
Submesh submesh = model.submeshes[submeshIndex];
string materialName = "";
if (materialMap.TryGetValue(model.materials[submeshIndex], out materialName))
{
sb.AppendLine(string.Format("usemtl {0}", materialName));
}
else
{
sb.AppendLine(string.Format("usemtl {0}", "null"));
}
int[] indexes = submesh.m_Indexes;
int inc = submesh.m_Topology == MeshTopology.Quads ? 4 : 3;
int inc1 = inc - 1;
int o0 = reverseWinding ? inc1 : 0;
int o1 = reverseWinding ? inc1 - 1 : 1;
int o2 = reverseWinding ? inc1 - 2 : 2;
int o3 = reverseWinding ? inc1 - 3 : 3;
for (int ff = 0; ff < indexes.Length; ff += inc)
{
int p0 = positionIndexMap[indexes[ff + o0]] + positionOffset;
int p1 = positionIndexMap[indexes[ff + o1]] + positionOffset;
int p2 = positionIndexMap[indexes[ff + o2]] + positionOffset;
int t0 = -1;
int t1 = -1;
int t2 = -1;
if (textureIndexMap != null)
{
t0 = textureIndexMap[indexes[ff + o0]] + textureOffset;
t1 = textureIndexMap[indexes[ff + o1]] + textureOffset;
t2 = textureIndexMap[indexes[ff + o2]] + textureOffset;
}
int n0 = -1;
int n1 = -1;
int n2 = -1;
if (normalIndexMap != null)
{
n0 = normalIndexMap[indexes[ff + o0]] + normalOffset;
n1 = normalIndexMap[indexes[ff + o1]] + normalOffset;
n2 = normalIndexMap[indexes[ff + o2]] + normalOffset;
}
if (inc == 4)
{
int p3 = positionIndexMap[indexes[ff + o3]] + positionOffset;
int n3 = normalIndexMap[indexes[ff + o3]] + normalOffset;
int t3 = textureIndexMap[indexes[ff + o3]] + textureOffset;
// sb.AppendLine(string.Format(CultureInfo.InvariantCulture,
// "f {0}/{4}/{8} {1}/{5}/{9} {2}/{6}/{10} {3}/{7}/{11}",
// p0, p1, p2, p3,
// t0, t1, t2, t3,
// n0, n1, n2, n3
// ));
throw new NotSupportedException();
}
else
{
string format;
if (textureIndexMap != null && normalIndexMap != null)
{
format = "f {0}/{3}/{6} {1}/{4}/{7} {2}/{5}/{8}";
}
else if (textureIndexMap == null && normalIndexMap != null)
{
format = "f {0}//{6} {1}//{7} {2}//{8}";
}
else if (textureIndexMap != null && normalIndexMap == null)
{
format = "f {0}/{3} {1}/{4} {2}/{5}";
}
else
{
format = "f {0} {1} {2}";
}
sb.AppendLine(string.Format(CultureInfo.InvariantCulture,
format,
p0, p1, p2,
t0, t1, t2,
n0, n1, n2
));
}
}
sb.AppendLine();
}
positionOffset += positionCount;
normalOffset += normalCount;
textureOffset += textureCount;
}
return(sb.ToString());
}