【发布时间】：2014-12-03 09:58:19
【问题描述】：
我正在制作一个 3D 游戏，其中有一个带有跟随摄像头的玩家。在我开始使用真实模型之前，我使用了立方体并使用 displaylist 渲染它，一切都很好。然而，现在我正在导入具有更多顶点的完整 3D 模型，我研究了 VBO。我为我的 VBO 设置了完整的结构，我可以看到最初绘制的模型，但它是在游戏世界的中心绘制的。当我移动播放器时，模型没有按应有的方式平移。模型不会移动其位置。
这是我最初用来将播放器绘制为矩形的代码（有效）：
public static void drawRectPrism(float centerx, float centery, float centerz, float length, float height, float width, float rx, float ry, float rz)
{
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
{
glTranslatef(centerx, centery, centerz);
glRotatef(rx, 1, 0, 0);
glRotatef(ry, 0, 1, 0);
glRotatef(rz, 0, 0, 1);
glTranslatef(-centerx, -centery, -centerz);
glTranslatef(-length/2f, -height/2f, -width/2f);
glBegin(GL_QUADS);
{
glColor3f(1.0f, 0, 0);
glVertex3f(centerx, centery, centerz);
glVertex3f(centerx + length, centery, centerz);
glVertex3f(centerx + length, centery + height, centerz);
glVertex3f(centerx, centery + height, centerz);
glColor3f(0, 1.0f, 0);
glVertex3f(centerx, centery, centerz + width);
glVertex3f(centerx + length, centery, centerz + width);
glVertex3f(centerx + length, centery + height, centerz + width);
glVertex3f(centerx, centery + height, centerz + width);
glColor3f(0, 0, 1.0f);
glVertex3f(centerx, centery, centerz);
glVertex3f(centerx, centery + height, centerz);
glVertex3f(centerx, centery + height, centerz + width);
glVertex3f(centerx, centery, centerz + width);
glColor3f(0, 1.0f, 1.0f);
glVertex3f(centerx + length, centery, centerz);
glVertex3f(centerx + length, centery + height, centerz);
glVertex3f(centerx + length, centery + height, centerz + width);
glVertex3f(centerx + length, centery, centerz + width);
glColor3f(1.0f, 1.0f, 0);
glVertex3f(centerx, centery, centerz);
glVertex3f(centerx + length, centery, centerz);
glVertex3f(centerx + length, centery, centerz + width);
glVertex3f(centerx, centery, centerz + width);
glColor3f(1.0f, 0, 1.0f);
glVertex3f(centerx, centery + height, centerz);
glVertex3f(centerx + length, centery + height, centerz);
glVertex3f(centerx + length, centery + height, centerz + width);
glVertex3f(centerx, centery + height, centerz + width);
}
glEnd();
}
glPopMatrix();
}
我在比其他人更好的地方尝试了几种不同的方法，并且可能实现了糟糕的编程结构，但我认为它仍然可以工作。
第一次尝试：调整矩形代码以加载我的顶点和模型，而不是特定的矩形顶点：
public void translate(float x, float y, float z, float rx, float ry, float rz)
{
File f = new File("graveDigga.obj");
try{
m = OBJLoader.loadModel(f);
}
catch(FileNotFoundException e)
{
e.printStackTrace();
Display.destroy();
System.exit(1);
}
catch(IOException e)
{
e.printStackTrace();
Display.destroy();
System.exit(1);
}
displayListChar = glGenLists(1);
glNewList(displayListChar, GL_COMPILE);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
{
glTranslatef(x, y, z);
glRotatef(rx, 1, 0, 0);
glRotatef(ry, 0, 1, 0);
glRotatef(rz, 0, 0, 1);
//glTranslatef(-x, -y, -z);
//glTranslatef(-length/2f, -height/2f, -width/2f);
glBegin(GL_TRIANGLES);
for(Face face : m.faces)
{
Vector2f t1 = m.textures.get((int) face.textures.x - 1);
glTexCoord2f(t1.x +x ,1-(t1.y +y ));
Vector3f n1 = m.normals.get((int) face.normal.x-1);
glNormal3f(n1.x +x ,n1.y+y,n1.z +z);
Vector3f v1 = m.vertices.get((int) face.vertex.x-1);
glVertex3f(v1.x +x,v1.y+y,v1.z+z);
Vector2f t2 = m.textures.get((int) face.textures.y - 1);
glTexCoord2f(t2.x +x, 1 - (t2.y+y ));
Vector3f n2 = m.normals.get((int) face.normal.y-1);
glNormal3f(n2.x+x,n2.y+y ,n2.z+z);
Vector3f v2 = m.vertices.get((int) face.vertex.y-1);
glVertex3f(v2.x+x,v2.y+y ,v2.z+z);
Vector2f t3 = m.textures.get((int) face.textures.z - 1);
glTexCoord2f(t3.x +x, 1 - (t3.y +y));
Vector3f n3 = m.normals.get((int) face.normal.z-1);
glNormal3f(n3.x+x,n3.y+y,n3.z +z);
Vector3f v3 = m.vertices.get((int) face.vertex.z-1);
glVertex3f(v3.x+x,v3.y+y,v3.z +z);
}
glEnd();
}
glPopMatrix();
//}
//glPopMatrix();
build();
}
接下来我尝试通过从该数据创建 VBO 并在我的游戏循环中调用 rander 方法来显示模型。在调用渲染之前，我会运行代码以尝试转换 VBO 的位置，但没有发生任何事情。
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
{
//glLoadIdentity();
glTranslatef(x,y,z);
glRotatef(rx, 1, 0, 0);
glRotatef(ry, 0, 1, 0);
glRotatef(rz, 0, 0, 1);
glTranslatef(-x,-y,-z);
glDrawArrays(GL_TRIANGLES, 0, m.faces.size() * 3);
}
我不确定我是否应该为此使用着色器，但我的一部分人在质疑为什么在世界空间中移动 3D 模型很困难？有没有一种更容易临时实施的凌乱方式？
【问题讨论】：