File size: 3,738 Bytes
2c55b92 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 | // Copyright 2019 DeepMind Technologies Limited
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using UnityEngine;
namespace Mujoco {
/// <summary>
/// Scale vertex data manually line by line. We skip normals. Warning: Parameter vertex points
/// (`vp`) were unclear to me how to handle with scaling, if you use them and notice an issue
/// please report it.
/// </summary>
public static class ObjMeshImportUtility {
private static Vector3 ToXZY(float x, float y, float z) => new Vector3(x, z, y);
public static void CopyAndScaleOBJFile(string sourceFilePath, string targetFilePath,
Vector3 scale) {
// OBJ files are human-readable
string[] lines = File.ReadAllLines(sourceFilePath);
StringBuilder outputBuilder = new StringBuilder();
// Culture info for consistent decimal point handling
CultureInfo invariantCulture = CultureInfo.InvariantCulture;
scale = ToXZY(scale.x, scale.y, scale.z);
foreach (string line in lines) {
if (line.StartsWith("v ")) // Vertex line
{
// Split the line into components
string[] parts = line.Split(' ');
if (parts.Length >= 4) {
// Scale the vertex. It is unclear to me why flipping along x axis was necessary,
// but without it meshes were incorrectly oriented.
float x = -float.Parse(parts[1], invariantCulture) * scale.x;
float y = float.Parse(parts[2], invariantCulture) * scale.y;
float z = float.Parse(parts[3], invariantCulture) * scale.z;
var swizzled = ToXZY(x, y, z);
outputBuilder.AppendLine(
$"v {swizzled.x.ToString(invariantCulture)} "+
$"{swizzled.y.ToString(invariantCulture)} "+
$"{swizzled.z.ToString(invariantCulture)}");
}
} else if (line.StartsWith("vn ")) {
// We swizzle the normals too
string[] parts = line.Split(' ');
if (parts.Length >= 4) {
float x = -float.Parse(parts[1], invariantCulture);
float y = float.Parse(parts[2], invariantCulture);
float z = float.Parse(parts[3], invariantCulture);
var swizzled = ToXZY(x, y, z);
outputBuilder.AppendLine(
$"vn {swizzled.x.ToString(invariantCulture)} "+
$"{swizzled.y.ToString(invariantCulture)} "+
$"{swizzled.z.ToString(invariantCulture)}");
}
} else if (line.StartsWith("f ") && scale.x*scale.y*scale.z < 0) {
// Faces definition, flip face by reordering vertices
string[] parts = line.Split(' ');
if (parts.Length >= 4) {
outputBuilder.Append(parts[0]+" ");
var face = parts.Skip(1).ToArray();
if (face.Length >= 3) {
outputBuilder.Append(face[0]+" ");
outputBuilder.Append(face[2]+" ");
outputBuilder.Append(face[1]);
}
outputBuilder.AppendLine();
}
} else {
// Copy non-vertex lines as-is
outputBuilder.AppendLine(line);
}
}
// Write the scaled OBJ to the target file
File.WriteAllText(targetFilePath, outputBuilder.ToString());
}
}
}
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