Question

我是OpenGL android新手。我在填充纹理时加载了Obj模型，但纹理没有完全填充在对象上。它在一些部分上填充纹理而不是在完整模型上。我附上了两张图片，其中有一个没有纹理的模型，另一个带有纹理但纹理不完整的模型。

这是我的纹理图像：

Texture

package com.amplimesh.models;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.util.ArrayList;
import java.util.StringTokenizer;

import javax.microedition.khronos.opengles.GL10;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLUtils;

import com.amplimesh.renderer.RendererView;
import com.amplimesh.util.Point3;

/**
 * Object Loader and draw the texture and object.
 * @author Ajay
 */
public class ObjModel {

    /**
     * It fill the texture into the mesh
     * @param context
     * @param gl
     */
    public void bindTextures(Context context, GL10 gl) {
        Bitmap bitmap;
        try {
            InputStream is = context.getAssets().open("textures/"+RendererView.textureFileName);
            bitmap = BitmapFactory.decodeStream(is);
            if(bitmap != null) {
                // generate one texture pointer
                gl.glGenTextures(1, mTextures, 0);
                // ...and bind it to our array
                gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextures[0]);

                // create nearest filtered texture
                gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
                gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);

                //Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
                //gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_REPEAT);
                //gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_REPEAT);

                // Use Android GLUtils to specify a two-dimensional texture image from our bitmap 
                GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
                // Clean up
                bitmap.recycle();
            }
        } catch (java.io.IOException e) {
            return;
        }
    }

    /**
     * It draw the object.
     * @param gl
     */
    public void draw(GL10 gl) {
        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
        gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);
        for (Model model : mModels) {

            gl.glVertexPointer(3, GL10.GL_FLOAT, 0, model.v);
            if (model.vt != null && mTextures != null) {
                gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextures[0]);
                gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, model.vt);
            }

            if (model.vn != null) {
                gl.glNormalPointer(GL10.GL_FLOAT, 0, model.vn);
            }
            gl.glDrawArrays(GL10.GL_TRIANGLES, 0, model.v_size);

        }

        gl.glDisableClientState(GL10.GL_NORMAL_ARRAY);
        gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
    }

    /**
     * It Load the object from stream.
     * @param is
     * @param texture_name
     * @return
     * @throws IOException
     */
    public static ObjModel loadFromStream(InputStream is, String texture_name) throws IOException {
        ObjModel obj = ObjLoader.loadFromStream(is);
        return obj;
    }

    private Model mModels[];
    private int mTextures[] = new int[1];;

    /**
     * It read the the obj file.
     * @author Ajay
     */
    private static class ObjLoader {

        public static ObjModel loadFromStream(InputStream is) throws IOException {
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            ObjModel obj = new ObjModel();
            ArrayList<Point3> v = new ArrayList<Point3>();
            ArrayList<Point3> vt = new ArrayList<Point3>();
            ArrayList<Point3> vn = new ArrayList<Point3>();
            ArrayList<Face> f = new ArrayList<Face>();

            ArrayList<Model> o = new ArrayList<Model>();

            boolean o_pending=false;

            while(reader.ready()) {
                String line = reader.readLine();
                if (line == null) 
                    break;

                StringTokenizer tok = new StringTokenizer(line);
                String cmd = tok.nextToken();

                if (cmd.equals("o")) {
                    if (o_pending) {
                        Model model = new Model();
                        model.fill(f, vt.size() > 0, vn.size() > 0);
                        o.add(model);
                    }
                    else {
                        o_pending=true;
                    }
                }
                else
                    if (cmd.equals("v")) {
                        v.add(read_point(tok));
                    }
                    else
                        if (cmd.equals("vn")) {
                            vn.add(read_point(tok));
                        }
                        else
                            if (cmd.equals("vt")) {
                                vt.add(read_point(tok));
                            }
                            else
                                if (cmd.equals("f")) {
                                    if (tok.countTokens() != 3)
                                        continue;

                                    Face face = new Face(3);
                                    while (tok.hasMoreTokens()) {
                                        StringTokenizer face_tok = new StringTokenizer(tok.nextToken(), "/");

                                        int v_idx = -1;
                                        int vt_idx = -1;
                                        int vn_idx = -1;
                                        v_idx = Integer.parseInt(face_tok.nextToken());
                                        if (face_tok.hasMoreTokens()) vt_idx = Integer.parseInt(face_tok.nextToken());
                                        if (face_tok.hasMoreTokens()) vn_idx = Integer.parseInt(face_tok.nextToken());

                                        //Log.v("objmodel", "face: "+v_idx+"/"+vt_idx+"/"+vn_idx);

                                        face.addVertex(
                                                v.get(v_idx-1),
                                                vt_idx == -1 ? null : vt.get(vt_idx-1),
                                                        vn_idx == -1 ? null : vn.get(vn_idx-1)
                                                );
                                    }
                                    f.add(face);
                                }
            }

            if (o_pending) {
                Model model = new Model();
                model.fill(f, vt.size() > 0, vn.size() > 0);
                o.add(model);
            }

            obj.mModels = new Model[o.size()];
            o.toArray(obj.mModels);
            return obj;
        }

        private static Point3 read_point(StringTokenizer tok) {
            Point3 ret = new Point3();
            if (tok.hasMoreTokens()) {
                ret.x = Float.parseFloat(tok.nextToken());
                if (tok.hasMoreTokens()) {
                    ret.y = Float.parseFloat(tok.nextToken());
                    if (tok.hasMoreTokens()) {
                        ret.z = Float.parseFloat(tok.nextToken());
                    }
                }
            }
            return ret;
        }

    }

    private static class Face {
        Point3 v[];
        Point3 vt[];
        Point3 vn[];
        int size;
        int count;

        public Face(int size) {
            this.size = size;
            this.count = 0;
            this.v = new Point3[size];
            this.vt = new Point3[size];
            this.vn = new Point3[size];
        }

        public boolean addVertex(Point3 v, Point3 vt, Point3 vn) {
            if (count >= size)
                return false;
            this.v[count] = v;
            this.vt[count] = vt;
            this.vn[count] = vn;
            count++;
            return true;
        }

        public void pushOnto(FloatBuffer v_buffer, FloatBuffer vt_buffer, FloatBuffer vn_buffer) {
            int i;
            for (i=0; i<size; i++) {
                v_buffer.put(v[i].x); v_buffer.put(v[i].y); v_buffer.put(v[i].z);

                if (vt_buffer != null && vt[i] != null) {
                    vt_buffer.put(vt[i].x); vt_buffer.put(vt[i].y);
                }

                if (vn_buffer != null && vn[i] != null) {
                    vn_buffer.put(vn[i].x); vn_buffer.put(vn[i].y); vn_buffer.put(vn[i].z);
                }
            }
        }
    }

    /**
     * It hold the vertex buffer, vertex normal and texture.
     * @author Ajay
     */
    private static class Model {
        public FloatBuffer v;
        public FloatBuffer vt;
        public FloatBuffer vn;
        public int v_size;

        public void fill(ArrayList<Face> faces, boolean has_tex, boolean has_normals) {
            int f_len = faces.size();

            this.v_size = f_len * 3;

            ByteBuffer tBuf = ByteBuffer.allocateDirect(this.v_size*3 * 4);
            tBuf.order(ByteOrder.nativeOrder());
            this.v = tBuf.asFloatBuffer();

            if (has_tex) {
                ByteBuffer vtBuf = ByteBuffer.allocateDirect(this.v_size*3 * 4);
                vtBuf.order(ByteOrder.nativeOrder());
                this.vt = vtBuf.asFloatBuffer();
            }

            if (has_normals) {
                ByteBuffer vnBuf = ByteBuffer.allocateDirect(this.v_size*3 * 4);
                vnBuf.order(ByteOrder.nativeOrder());
                this.vn = vnBuf.asFloatBuffer();
            }

            int i;
            for (i=0; i < f_len; i++) {
                Face face = faces.get(i);
                face.pushOnto(this.v, this.vt, this.vn);
            }

            this.v.rewind();
            if (this.vt != null)
                this.vt.rewind();
            if (this.vn != null)
                this.vn.rewind();
        }
    }
}

Render.java

public void start() {
    mRenderer = new Renderer();
    setEGLContextClientVersion(1);
    setPreserveEGLContextOnPause(true);
    setRenderer(mRenderer);
}

float mRotationFinal=-1f;
float mRotationDelta=0f;
int mRotationAxis=-1;

private class Renderer implements GLSurfaceView.Renderer {
    public Renderer() {
        setEGLConfigChooser(8, 8, 8, 8, 16, 0);
        getHolder().setFormat(PixelFormat.TRANSLUCENT);
        setZOrderOnTop(true);
    }

    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        gl.glClearColor(0.0f,0.0f,0.0f, 0.0f);
        gl.glEnable(GL10.GL_DEPTH_TEST);
        gl.glDepthFunc(GL10.GL_LEQUAL);
        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);

        gl.glEnable(GL10.GL_TEXTURE_2D);
        gl.glShadeModel(GL10.GL_SMOOTH);
    }

    public void onSurfaceChanged(GL10 gl, int w, int h) {
        mViewWidth = (float)w;
        mViewHeight = (float)h;
        gl.glViewport(0,0,w,h);

        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        GLU.gluPerspective(gl, 45, mViewWidth/mViewHeight, 0.1f, 100f);

        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();
    }

    public void onDrawFrame(GL10 gl) {
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        gl.glPushMatrix();

        gl.glDisable(GL10.GL_DITHER); 

        GLU.gluLookAt(gl, 0, 0, 10, 0, 0, 0, 0, 1, 0);

        //draw_model
        gl.glPushMatrix();

        if(mOrigin != null && mRotate != null) {
            gl.glTranslatef(mOrigin.x, mOrigin.y, mOrigin.z);
            gl.glRotatef(mRotate.x, 1f, 0f, 0f);
            gl.glRotatef(mRotate.y, 0f, 1f, 0f);
            gl.glRotatef(mRotate.z, 0f, 0f, 1f);
        }

        if(mModel != null) {
            mModel.draw(gl);
            if(!RendererView.textureFileName.equals(""))
                mModel.bindTextures(mContext, gl);
        }

        gl.glPopMatrix();
        gl.glPopMatrix();

        if(isPictureTake) {

            w = getWidth();
            h = getHeight();
            b = new int[w*(y+h)];
            bt = new int[w*h];

            IntBuffer ib = IntBuffer.wrap(b);
            ib.position(0);
            gl.glReadPixels(0, 0, w, h, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, ib);
            createBitmapFromGLSurface(context);
            isPictureTake = false;
        }
    }
}

Point3.java

public class Point3 extends Object {
    public float x;
    public float y;
    public float z;

    public Point3() {
    x = 0.0f;
    y = 0.0f;
    z = 0.0f;
    }

    public Point3(float x, float y, float z) {
    set(x,y,z);
    }

    public Point3(Point3 src) {
    set(src.x, src.y, src.z);
    }

    public final boolean equals(float x, float y, float z) {
    return ((this.x == x) && (this.y == y) && (this.z == z));
    }

    public void set(float x, float y, float z) {
    this.x = x;
    this.y = y;
    this.z = z;
    }

    public void minmax(float minx, float miny, float minz, float maxx, float maxy, float maxz) {
    this.x = Math.min(Math.max(this.x, minx), maxx);
    this.y = Math.min(Math.max(this.y, miny), maxy);
    this.z = Math.min(Math.max(this.z, minz), maxz);
    }

    @Override 
    public boolean equals(Object o) {
    if (this == o) 
        return true;

    if (!(o instanceof Point3)) 
        return false;

    Point3 obj = (Point3)o;
    return this.equals(obj.x, obj.y, obj.z);
    }

    @Override
    public String toString() {
    return "("+x+","+y+","+z+")";
    }

    @Override 
    public int hashCode() { throw new UnsupportedOperationException(); }
}

Screen 1

Screen 2

Screen 3

Answer 1

经过仔细检查后，我注意到你的纹理坐标数组是Point3，但你的纹理坐标指针使用2个GL_FLOAT分量和步长为0.在第一个顶点之后，你的坐标指针将是不提供有效数据。

有几种方法可以解决这个问题：

使用Point2数组（如果存在此类内容）

使用12个字节的步幅：

gl.glTexCoordPointer (2, GL10.GL_FLOAT, 12, model.vt);

使用3D纹理坐标：

gl.glTexCoordPointer (3, GL10.GL_FLOAT, 0, model.vt);

纹理中没有完全渲染的渲染器

1 个答案: