如何分别对3D模型进行纹理化(使用不同的纹理文件)

Question

我有一个在Blender中制作的3D文件，并导出到java（.OBJ文件）中，该文件将他的纹理分离成一些文件。在这个.obj文件中，它有一些用USEMTL缩放的字段及其部分的名称（纹理文件）。然而，当我在屏幕上绘制它时，他只显示最后一个USEMTL名称。我的问题是：我如何才能让他以正确的方式阅读和纹理化？不重叠其他纹理？

这是具有.obj加载程序的类

    public MLoader(String path, Model m) throws IOException {
            @SuppressWarnings("resource")
            BufferedReader reader = new BufferedReader(new FileReader(new File(path)));
            String line;
    while ((line = reader.readLine()) != null) {
        if (line.startsWith("v ")) {
            float 
            v1 = Float.valueOf(line.split(" ")[1]), 
            v2 = Float.valueOf(line.split(" ")[2]), 
            v3 = Float.valueOf(line.split(" ")[3]);
            Vector3f v = new Vector3f (v1, v2, v3);
            m.vertex.add(v);
        } if (line.startsWith("usemtl ")){
            String name = String.valueOf(line.split(" ")[1]);
            m.nameTexture.add(name);
            continue;
        } if (line.startsWith("f ")) {
            float 
            v1 = Float.valueOf(line.split(" ")[1].split("/")[0]),
            v2 = Float.valueOf(line.split(" ")[2].split("/")[0]),
            v3 = Float.valueOf(line.split(" ")[3].split("/")[0]),
            n1 = Float.valueOf(line.split(" ")[1].split("/")[1]),
            n2 = Float.valueOf(line.split(" ")[2].split("/")[1]),
            n3 = Float.valueOf(line.split(" ")[3].split("/")[1]);
            Vector3f
            v = new Vector3f (v1, v2, v3),
            n = new Vector3f (n1, n2, n3);
            m.face.add(new Faces(v, n));
        }if (line.startsWith("vt ")) {
            float 
            vt1 = Float.valueOf(line.split(" ")[1]), 
            vt2 = Float.valueOf(line.split(" ")[2]);
            Vector2f vt = new Vector2f (vt1, vt2);
            m.vertexTexture.add(vt);
        } 
    }
}

正如你所看到的，我创建了一个IF语句，只是为了得到这个usemtl东西（在.obj文件中）——纹理名称（在单独的文件中），只是为了看看我是否可以单独绑定它们。但我很难做到这一点（也许，逻辑不在我这边）。如何继续？

其他类别：

纹理类

public class Textures {
    public Texture[] tx;
    public void setNumTex(int i) {
        tx = new Texture[i];
    }
    public void setTexture(String format, String name, int i) {
        try {
            tx[i] = TextureLoader.getTexture(format, new FileInputStream(new File("res/Textures/" + name + format)));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public void texturing(Vector2f ft1, Vector2f ft2, int indexx) {
        for (int i=0; i<indexx; i++) {
            tx[i].bind();
        }
        glTexCoord2f(ft1.x, ft1.y);
        glTexCoord2f(ft2.x, ft2.y);
    }
}

渲染类

public class Renderer {
    Model m;
    public void loadContent(String objPath) {
        //Everithing that is loading is been putting here
        m = Model.getModel("res/Models/" + objPath);
        m.loadTex();
    }
    public void render() {
        glEnable(GL_SMOOTH);
        m.renderModel();
    }
}

型号类别

public class Model {
    Textures tx;
    List<Vector3f> vertex, norms;
    List<Vector2f> vertexTexture;
    List<Faces> face;
    List<String> nameTexture;
    String name[];
    private int numTex = 0;
    Vector2f 
    t1 = new Vector2f(), t2 = new Vector2f();
    Vector3f
    v1 = new Vector3f(), v2 = new Vector3f(), v3 = new Vector3f(),
    n1 = new Vector3f(), n2 = new Vector3f(), n3 = new Vector3f(),
    public Model(String path)throws 
    LWJGLException, FileNotFoundException, IOException {
        vertex = new ArrayList<Vector3f>();
        norms = new ArrayList<Vector3f>();
        vertexTexture = new ArrayList<Vector2f>();
        face = new ArrayList<Faces>();
        nameTexture = new ArrayList<String>();
        tx = new Textures();
        new MLoader(path, this);
    }
    public static Model getModel(String path, Vector3f position, Vector3f rotation) {
        try {
            return new Model(path, position, rotation);
        } catch (LWJGLException | IOException e) {
            e.printStackTrace();
        }
        return null;
    }
    public void loadTex() {
        name = new String[nameTexture.toArray().length];
        tx.setNumTex(nameTexture.toArray().length);
        for (int i=0; i<name.length; i++) {
            name[i] = nameTexture.get(i);
            numTex += 1;
            tx.setTexture(".TGA", name[i], i);
        }
    }
    public void renderModel() {
        glPushMatrix();
        glPolygonMode(GL_FRONT_AND_BACK, GL_DEPTH_BUFFER_BIT);
        glEnable(GL_TEXTURE_2D);
        glBegin(GL_TRIANGLES);
        {
            for (Faces f : face) {
                v1 = vertex.get((int) f.v.x - 1);
                v2 = vertex.get((int) f.v.y - 1);
                v3 = vertex.get((int) f.v.z - 1);
                n1 = vertex.get((int) f.n.x - 1);
                n2 = vertex.get((int) f.n.y - 1);
                n3 = vertex.get((int) f.n.z - 1);
                t1 = vertexTexture.get((int) f.n.x - 1); //
                t2 = vertexTexture.get((int) f.n.y - 1); // 
                //Vertexes
                glVertex3f(v1.x, v1.y-3.4f, v1.z-0.53f);
                glVertex3f(v2.x, v2.y-3.4f, v2.z-0.53f);
                glVertex3f(v3.x, v3.y-3.4f, v3.z-0.53f);
                //Normals
                glNormal3f(n1.x, n1.y-3.4f, n1.z-0.53f);
                glNormal3f(n2.x, n2.y-3.4f, n2.z-0.53f);
                glNormal3f(n3.x, n3.y-3.4f, n3.z-0.53f);
                //Texture
                tx.texturing(t1, t2, numTex);
                //tx.texturing(n1, n2, n3);             
            }
        }
        glEnd();
        glDisable(GL_TEXTURE_2D);
        glPopMatrix();
    }
}

Answer 1

我不会放任何代码，因为对于两行解决方案来说，您的问题相当复杂。但在这里，它通常是如何在一个简单的3D引擎中工作的。网格的多重纹理意味着网格被分解为2个或多个子网格。我不是搅拌机专家，但我相信它能够像Autodesk 3D studio max一样导出带有子网格树的网格。现在，当您将这样的网格导入程序时，您应该能够将所有这些子网格解析为单独的实体。每个这样的子网格都有自己的顶点、纹理坐标和法线。发出draw调用时，您将逐个迭代所有子网格，并在自己的draw调用中绘制每个子网格。因此，在每次绘制调用时，您还应该能够附加一个用于特定子网格的唯一纹理。仅此而已。现在由你来决定如何设计这样一个系统。希望能有所帮助。

Answer 2

好的，我发现了问题所在。解决方案如下：在类MLoader中，我只需要在"usemtl"部分放一个"distinguisher"。有了它，当他在"F SECTION"时，当他返回并将脸添加到"faceArray"中时，他只会添加更多的内容。

示例：

face.add(1, 2, 3);
faceArray.add(face); //Assuming that the face has his 1, 2, 3 thing

当他再次转到"f"if时，他添加

face.add(4, 5, 6);
faceArray.add(face); //But, this time, when he adds the face, it already had 1, 2, 3, 
//so, he's with '1, 2, 3, 4, 5, 6' into him

以下是我所做的更改（只是更改）：

Class MLoader：

public MLoader(String path, Model m) throws IOException {
...
        while ((line = reader.readLine()) != null) {
            ...
            } if (line.contains("g ")) {
                index = 0;
            } if (line.startsWith("usemtl ") && index == 0){
                String name = String.valueOf(line.split(" ")[1]);   
                m.nameTexture.add(name);
                m.faceArray.add(m.face);
                m.face = new ArrayList<Faces>();
                index = 1;
            } if (line.contains("f ") && index == 1) {
                ...
            }

类别模型：

int numTex = 0;
List<List <Faces>> faceArray;
...
public void loadTex() {
    for (String n : nameTexture) {
        tx.loadTexture("TGA", n);
        numTex ++;
    }
}
...
public void renderModel() {
...
glEnable(GL_TEXTURE_2D);
        for (int i = 0; i < numTex; i++) {
            tx.tx.get(i).bind();
            glBegin(GL_TRIANGLES);
            {
                for (Faces f : faceArray.get(i)) {              
                    ...
                    }
                }
                glEnd();
            }
            glDisable(GL_TEXTURE_2D);
            ...
    }