【发布时间】：2013-05-17 18:37:10
【问题描述】：
我创建了一个 3D 游戏，其中代理可以在多个方向（北、南...）移动。
它工作正常，但是当我在代码中添加另一个形状 - 金字塔 - 时，当我 移动代理，金字塔与他一起移动，这意味着它与代理（也称为相机）的移动保持一致。
知道如何使形状静态吗？
启用gl2.glLoadIdentity(); 行会导致金字塔粘在相机上。禁用gl2.glLoadIdentity(); 会导致金字塔不出现。
代码：
类：Pyramid.java
import javax.media.opengl.GL2;
public class Pyramid {
private int m_pyramid;
public void createPyramid(GL2 gl2)
{
m_pyramid = gl2.glGenLists(1);
gl2.glNewList(m_pyramid, GL2.GL_COMPILE);
// set texture parameters
gl2.glTexParameteri ( GL2.GL_TEXTURE_2D,GL2.GL_TEXTURE_WRAP_T,GL2.GL_LINEAR_MIPMAP_LINEAR);
gl2.glTexParameteri( GL2.GL_TEXTURE_2D,GL2.GL_TEXTURE_WRAP_S,GL2.GL_LINEAR_MIPMAP_LINEAR);
gl2.glBegin(GL2.GL_TRIANGLES); // of the pyramid
// Font-face triangle
gl2.glTexCoord3f(1.0f, 0.0f, 0.0f); // Red
gl2.glVertex3d(0.0f, 1.0f, 0.0f);
gl2.glTexCoord3f(0.0f, 1.0f, 0.0f); // Green
gl2.glVertex3d(-1.0f, -1.0f, 1.0f);
gl2.glTexCoord3f(0.0f, 0.0f, 1.0f); // Blue
gl2.glVertex3d(1.0f, -1.0f, 1.0f);
// Right-face triangle
gl2.glTexCoord3f(1.0f, 0.0f, 0.0f); // Red
gl2.glVertex3d(0.0f, 1.0f, 0.0f);
gl2.glTexCoord3f(0.0f, 0.0f, 1.0f); // Blue
gl2.glVertex3d(1.0f, -1.0f, 1.0f);
gl2.glTexCoord3f(0.0f, 1.0f, 0.0f); // Green
gl2.glVertex3d(1.0f, -1.0f, -1.0f);
// Back-face triangle
gl2.glTexCoord3f(1.0f, 0.0f, 0.0f); // Red
gl2.glVertex3d(0.0f, 1.0f, 0.0f);
gl2.glTexCoord3f(0.0f, 1.0f, 0.0f); // Green
gl2.glVertex3d(1.0f, -1.0f, -1.0f);
gl2.glTexCoord3f(0.0f, 0.0f, 1.0f); // Blue
gl2.glVertex3d(-1.0f, -1.0f, -1.0f);
// Left-face triangle
gl2.glTexCoord3f(1.0f, 0.0f, 0.0f); // Red
gl2.glVertex3d(0.0f, 1.0f, 0.0f);
gl2.glTexCoord3f(0.0f, 0.0f, 1.0f); // Blue
gl2.glVertex3d(-1.0f, -1.0f, -1.0f);
gl2.glTexCoord3f(0.0f, 1.0f, 0.0f); // Green
gl2.glVertex3d(-1.0f, -1.0f, 1.0f);
gl2.glEnd(); // of the pyramid
gl2.glEndList();
}
}
WorldController.java
class WorldController extends GLCanvas implements GLEventListener, KeyListener
{
private Point3D m_agent , m_center , m_coordinate1 , m_coordinate2 , m_coordinate3;
private GLU m_glu = new GLU();
private Pyramid m_pyra = new Pyramid();
public WorldController ()
{
this.addGLEventListener(this);
// initialize m_agent and axis
this.m_agent = new Point3D(750,200,1200);
this.m_coordinate1 = new Point3D(1,0,0);
this.m_coordinate2 = new Point3D(0,1,0);
this.m_coordinate3 = new Point3D(0,0,1);
this.m_center = new Point3D(0,0,0);
}
@Override
public void init (GLAutoDrawable gLDrawable)
{
GL2 gl2 = gLDrawable.getGL().getGL2(); // get the OpenGL graphics context
gl2.glEnable(GL2.GL_TEXTURE_2D); // get GL Utilities
gl2.glShadeModel(GL2.GL_SMOOTH);
gl2.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
gl2.glClearDepth(1.0f);
gl2.glEnable(GL2.GL_DEPTH_TEST);
gl2.glDepthFunc(GL2.GL_LEQUAL);
gl2.glHint(GL2.GL_PERSPECTIVE_CORRECTION_HINT, GL2.GL_NICEST);
gl2.glShadeModel(GL_SMOOTH); // blends colors nicely, and smoothes out lighting
// bind the pyramid with the current GL2
this.m_pyra.createPyramid(gl2);
/**
* Creating the listener
*/
((Component) gLDrawable).addKeyListener(this);
}
@Override
public void display(GLAutoDrawable gLDrawable)
{
final GL2 gl2 = gLDrawable.getGL().getGL2();
gl2.glClear(GL2.GL_COLOR_BUFFER_BIT | GL2.GL_DEPTH_BUFFER_BIT);
gl2.glLoadIdentity();
// set m_center and look at
m_center.setPoint(m_agent.getX() - m_coordinate3.getX() ,
m_agent.getY() - m_coordinate3.getY() ,
m_agent.getZ() - m_coordinate3.getZ());
m_glu.gluLookAt(m_agent.getX(),m_agent.getY(),m_agent.getZ(),
m_center.getX(),m_center.getY(),m_center.getZ(),
m_coordinate2.getX(),m_coordinate2.getY(),m_coordinate2.getZ());
/**
* pyramid
*/
gl2.glPushMatrix();
// gl2.glLoadIdentity();
gl2.glTranslatef(-2f, 0.0f, -10.0f); // translate left and into the screen
gl2.glRotatef(anglePyramid, 0.1f, 1.0f, -0.1f); // rotate about the y-axis
gl2.glCallList(5);
gl2.glPopMatrix(); // <-- and here?
anglePyramid += speedPyramid;
}
@Override
public void reshape(GLAutoDrawable gLDrawable,int x,int y,int width,int height)
{
GL2 gl2 = gLDrawable.getGL().getGL2(); // get the OpenGL 2 graphics context
if(height <= 0) height = 1; // prevent divide by zero
float aspect = (float)width / (float)height;
gl2.glMatrixMode(GL_PROJECTION);
gl2.glLoadIdentity();
m_glu.gluPerspective(50.0f, aspect, 1.0, 10000.0);
gl2.glMatrixMode(GL_MODELVIEW);
gl2.glLoadIdentity();
}
}
以下是代理移动时的一些照片：
可以解释问题的现场视频：http://www.youtube.com/watch?v=zCBqx69b_e4&feature=youtu.be
【问题讨论】：
-
在代码中，您将相机定位在哪里？我只看到了绘制金字塔的代码。
-
@TomásBadan：请看修改后的代码
标签： java opengl graphics 3d jogl