gluLookAt not working despite using Push/PopMatrix for transforms
I'm trying to use gluLookAt in an Android app to move the "camera" around, but I'm not seeing any results. I've looked around and I gather that any glLoadIndentity() calls will reset the matrix, cancelling the effect of the gluLookAt.
Problem is, no matter what I put in my gluLookAt call, nothing moves.
So here's the relevant part of my surface setup:
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glDisable(GL10.GL_DITHER);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glClearColor(0f, 0f, 0f, 0.5f);
gl.glClearDepthf(1.0f);
gl.glEnable(GL10.GL_DEPTH_TEST);
gl.glDepthFunc(GL10.GL_LEQUAL);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
GLU.gluPerspective(gl, 45f, (float) width / (float) height, 0.01f, 200f);
gl.glMatrixMode(GL10.GL_MODELVIEW);
}
And then my frame-drawing method is:
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
GLU.gluLookAt(gl, 0, 0, 100, 0, 0, 0, 0, 1, 0);
for (int i = 0; i < obj.size; i++) { // obj is an array of positions
obj = mObj[i];
gl.glPushMatrix();
gl.glLoadIdentity();
gl.glTranslatef(obj.position.x(), obj.position.y(), obj.position.z());
gl.glRotatef(obj.rotation.x(), 1f, 0f, 0f);
gl.glRotatef(obj.rotation.y(), 0f, 1f, 0f);
gl.glRotatef(obj.rotation.z(), 0f, 0f, 1f);
obj.draw(gl); // the objects 'draw' themselves
gl.glPopMatrix();
}
}
And here's an example of the draw() function of my objects, which essentially draw a bunch of elements:
class SomeObject {
public void draw(GL10 gl) {
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);
gl.glEnable(GL10.GL_CULL_FACE);
gl.glFrontFace(GL10.GL_CCW);
gl.glCullFace(GL10.GL_BACK);
gl.glColor4f(1f, 0f, 0f, 1f);
gl.glDrawElements(GL10.GL_TRIANGLES, SomeObject.fCount, GL10.GL_UNSIGNED_BYTE, faceBuffer);
gl.glColor4f(1, 1, 1, 1);
gl.glDisableClie开发者_运维知识库ntState(GL10.GL_NORMAL_ARRAY);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
}
}
Give this version a shot:
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, 100, 0, 0, 0, 0, 1, 0);
for (int i = 0; i < obj.size; i++) { // obj is an array of positions
obj = mObj[i];
gl.glPushMatrix();
gl.glTranslatef(obj.position.x(), obj.position.y(), obj.position.z());
gl.glRotatef(obj.rotation.x(), 1f, 0f, 0f);
gl.glRotatef(obj.rotation.y(), 0f, 1f, 0f);
gl.glRotatef(obj.rotation.z(), 0f, 0f, 1f);
obj.draw(gl); // the objects 'draw' themselves
gl.glPopMatrix();
}
}
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