/// <summary>
/// Asynchronously imports the given .obj file from the specified url
/// </summary>
/// <param name="url">The url to the .obj file</param>
/// <returns>The GameObject that was created for the imported .obj</returns>
public async Task <GameObject> ImportAsync(string url)
{
i5Debug.Log("Starting import", this);
Uri uri = new Uri(url);
// fetch the model
WebResponse <string> resp = await FetchModelAsync(uri);
// if there was an error, we cannot create anything
if (!resp.Successful)
{
i5Debug.LogError("Error fetching obj. No object imported.\n" + resp.ErrorMessage, this);
return(null);
}
// create the parent object
// it is a standard GameObject; its only purpose is to bundle the child objects
GameObject parentObject = ObjectPool <GameObject> .RequestResource(() => { return(new GameObject()); });
parentObject.name = System.IO.Path.GetFileNameWithoutExtension(uri.LocalPath);
// parse the .obj file
List <ObjParseResult> parseResults = await ParseModelAsync(resp.Content);
// for each sub-object in the .obj file, an own parse result was created
foreach (ObjParseResult parseResult in parseResults)
{
// check that the referenced mtl library is already loaded; if not: load it
if (!MtlLibrary.LibraryLoaded(parseResult.LibraryPath))
{
string mtlUri = UriUtils.RewriteFileUriPath(uri, parseResult.LibraryPath);
string libraryName = System.IO.Path.GetFileNameWithoutExtension(uri.LocalPath);
bool successful = await MtlLibrary.LoadLibraryAsyc(new Uri(mtlUri), libraryName);
if (!successful)
{
i5Debug.LogError("Could not load .mtl file " + parseResult.LibraryPath, this);
}
}
// get the material constructor of the sub-object
MaterialConstructor mat = MtlLibrary.GetMaterialConstructor(
System.IO.Path.GetFileNameWithoutExtension(uri.LocalPath),
parseResult.MaterialName);
if (mat != null)
{
// first get dependencies; this will e.g. fetch referenced textures
await mat.FetchDependencies();
parseResult.ObjectConstructor.MaterialConstructor = mat;
}
// construct the object and make it a child of the parentObject
parseResult.ObjectConstructor.ConstructObject(parentObject.transform);
}
return(parentObject);
}
/// <summary>
/// Parses the contents of a .mtl file
/// </summary>
/// <param name="uri">The full URI where the .mtl file is stored</param>
/// <param name="libraryContent">The line array of the file's content</param>
/// <returns>A list a material constructor for each material in the library</returns>
private List <MaterialConstructor> ParseMaterialLibrary(Uri uri, string[] libraryContent)
{
List <MaterialConstructor> materials = new List <MaterialConstructor>();
MaterialConstructor current = null;
int numberOfErrors = 0;
for (int i = 0; i < libraryContent.Length; i++)
{
string trimmedLine = libraryContent[i].Trim();
// newmtl and # (comment) can be executed also if there is no current material set
// skip empty lines
if (string.IsNullOrEmpty(trimmedLine))
{
continue;
}
else if (trimmedLine.StartsWith("newmtl"))
{
if (current != null)
{
materials.Add(current);
}
current = new MaterialConstructor();
current.Name = trimmedLine.Substring(6).TrimStart();
}
else if (trimmedLine.StartsWith("#"))
{
if (ExtendedLogging)
{
i5Debug.Log("Comment found: " + trimmedLine.Substring(1).TrimStart(), this);
}
}
// all other commands require an already initialized material
// this means that the line newmtl must have been read at least once until now
else
{
if (current != null)
{
// Kd sets the diffuse color
if (trimmedLine.StartsWith("Kd"))
{
string[] strValues = trimmedLine.Substring(2).TrimStart().Split(' ');
if (strValues.Length != 3)
{
numberOfErrors++;
if (ExtendedLogging)
{
i5Debug.LogError("Expected three color values but found " + strValues.Length, this);
}
continue;
}
if (ParserUtils.TryParseStringArrayToVector3(strValues, out Vector3 colorVector))
{
// could successfully parse color vector
Color albedo = colorVector.ToColor();
current.Color = albedo;
}
else
{
numberOfErrors++;
if (ExtendedLogging)
{
i5Debug.LogError("Could not parse color data", this);
}
}
}
// Ks sets the specular intensity
else if (trimmedLine.StartsWith("Ks"))
{
string[] strValues = trimmedLine.Substring(2).TrimStart().Split(' ');
if (strValues.Length != 3 && strValues.Length != 1)
{
numberOfErrors++;
if (ExtendedLogging)
{
i5Debug.LogError("Expected one or three smoothness values but found " + strValues.Length, this);
}
continue;
}
// we assume that all values are equal
if (float.TryParse(strValues[0], NumberStyles.Any, CultureInfo.InvariantCulture, out float smoothness))
{
// could successfully parse smoothness
current.SetFloat("_Glossiness", smoothness);
}
else
{
numberOfErrors++;
if (ExtendedLogging)
{
i5Debug.LogError("Could not parse color data", this);
}
}
}
// map_Kd sets the albedo texture
else if (trimmedLine.StartsWith("map_Kd"))
{
string texturePath = trimmedLine.Substring(6).TrimStart();
// rewrite the URI to the texture's path and then add a texture constructor to the material
string fullUri = UriUtils.RewriteFileUriPath(uri, texturePath);
current.SetTexture("_MainTex", new TextureConstructor(fullUri));
}
}
else
{
i5Debug.LogWarning("Material instruction line found but material has not yet been initialized. The .mtl-file is probably malformed.", this);
}
}
}
if (current != null)
{
materials.Add(current);
}
// check if materials were created
if (materials.Count == 0)
{
i5Debug.LogWarning(".mtl-file was read but no materials were parsed.", this);
}
return(materials);
}