Camera rotation | 易学教程

问题

As with my previous question i managed to create little solar system in opengl and jogl :) Now i want to rotate the camera to show it from different angles.
I managed to rotate the cubes, but their plane of movement remains unchanged.

GL3 gl = drawable.getGL().getGL3();

    gl.glClear(GL3.GL_COLOR_BUFFER_BIT | GL3.GL_DEPTH_BUFFER_BIT);
    //Model View Matrix

    //Mat4 mv = new Mat4();
    Mat4 mv = MatrixMath.lookAt(this.eyeX,this.eyeY,this.eyeZ,this.at,this.up);
    mv = mv.mul(MatrixMath.rotationZ(satellite));
    mv.set(2, 2, 0.0f);
    mv.set(2, 3, 0.0f);

    cubeprogram.passUniformMatrix(gl, "model_view", mv);

    gl.glDrawArrays( GL3.GL_TRIANGLES, 0, numVertices );

    angle += 2.0f;
    satellite = angle + 8.0f;
    if (angle > 360.0f)
    angle -= 360.0f;

    float positionX = setMovementX(angle, 0.8f);
    float positionZ = setMovementZ(angle, 0.8f);
   // mv = MatrixMath.lookAt(this.eyeX,this.eyeY,this.eyeZ,this.at,this.up);
    mv = mv.mul(MatrixMath.rotationZ(satellite));
    mv.set(0, 3, positionX);
    mv.set(2, 3, positionZ);
    cubeprogram.passUniformMatrix(gl, "model_view", mv);
    gl.glDrawArrays( GL3.GL_TRIANGLES, 0, numVertices );
    positionX = setMovementX(satellite, 0.2f);
    positionZ = setMovementZ(satellite, 0.2f);
    Mat4 sm = new Mat4( 1.0f,    0.0f,  0.0f,   positionX, 
            0.0f,    1.0f,  0.0f,   0.0f, 
            0.0f,    0.0f,  1.0f,   positionZ, 
            0.0f,    0.0f,  0.0f,   1.0f);
    mv = mv.mul(sm);
    mv = mv.mul(MatrixMath.rotationZ(angle));
    cubeprogram.use(gl);
    cubeprogram.passUniformMatrix(gl, "model_view", mv);
    gl.glDrawArrays( GL3.GL_TRIANGLES, 0, numVertices );
    cubeprogram.setUniformMatrix("projection", projection);`

// definitions

public static Mat4 lookAt(Vec4 eye, Vec4 at, Vec4 up) {
    final Vec4 eyeneg = eye.neg();

    final Vec4 n = VectorMath.normalize(eye.sub(at));
    final Vec4 u = VectorMath.normalize(VectorMath.cross(up, n));
    final Vec4 v = VectorMath.normalize(VectorMath.cross(n, u));
    final Vec4 t = new Vec4(0, 0, 0, 1);
    final Mat4 c = new Mat4(u, v, n, t);

    return c.mul(MatrixMath.translate(eyeneg));
}
public static Mat4 lookAt(float x, float y, float z, Vec4 at, Vec4 up) {
    final Vec4 eye = new Vec4(x, y, z, 1.0f);
    return lookAt(eye, at, up);
}

回答1:

Check jogl's pmvMatrix

for camera:

pmvMatrix.glMatrixMode(GLMatrixFunc.GL_PROJECTION);
pmvMatrix.glLoadIdentity();
pmvMatrix.gluPerspective(fov, aspect, zNear, zFar);
pmvMatrix.glMatrixMode(GLMatrixFunc.GL_MODELVIEW);
pmvMatrix.glLoadIdentity();
pmvMatrix.glRotatef(-pitch, 1, 0, 0);
pmvMatrix.glRotatef(-yaw, 0, 1, 0);
pmvMatrix.glRotatef(-roll, 0, 0, 1);
pmvMatrix.glTranslatef(-position.x, -position.y, -position.z);
pmvMatrix.update();

Fixed functions:

gl.glMatrixMode(GLMatrixFunc.GL_PROJECTION);
gl.glLoadMatrixf(pmvMatrix.glGetPMatrixf());
gl.glMatrixMode(GLMatrixFunc.GL_MODELVIEW);
gl.glLoadMatrixf(pmvMatrix.glGetMvMatrixf());

Shaders:

GLUniformData pmvMatrixUniform;

init code...

PMVMatrix pmvMatrix = ...;
state.attachObject("pmvMatrix", pmvMatrix);
pmvMatrixUniform = new GLUniformData("pmvMatrix", 4, 4, pmvMatrix.glGetPMvMatrixf());
state.ownUniform(pmvMatrixUniform);
state.uniform(gl, pmvMatrixUniform);

display code...

state.uniform(gl, pmvMatrixUniform);

来源：https://stackoverflow.com/questions/13462516/camera-rotation

标签

java

opengl

jogl