Sign in to follow this  

JOGL gluUnproject Problem

Recommended Posts

Hey everybody,

I did a search in the forum looking for other people having the same problem as me, but i found nothing... So i created a new thread here to see if someone could find what I'm missing.
The problem is that I'm trying to implement a picking function using gluUnproject to convert my window coords to my world cords under JOGL and the results doesn't seem to be fine.
I capture the mouse event using a mouse listener on my GLJPanel and use it on my display function. After having the window coords, I use gluUnproject to know where the click is on my world, but actually, these coords doesn't seem to be correct, my scene just isn't in the place the unprojected coords says.

I feel that I'm messing something up while setting the perspective projection, setting the gluLookAt position. I think the problem is on my stack.

This is my code and, by the way, I'm trying to pick a chess board:

[code]public void display(GLAutoDrawable glad)
GL gl = glad.getGL();
GLU glu = new GLU();

gl.glClearColor(1.0f, 1.0f, 1.0f, 0.0f); //backgroung color


glu.gluLookAt(camX, camY, camZ,
camPointX, camPointY, camPointZ,
0.0, 1.0, 0.0);

glu.gluPerspective(60.0, 1.0, 1.0, 1000.0);

if (mouse != null)
//Picking part
double x = (double)mouse.getX(), y = (double)mouse.getY();
mouse = null;
int viewport[] = new int[4];
double mvmatrix[] = new double[16];
double projmatrix[] = new double[16];
double realy = (double)viewport[3] - y - 1.0;
double wcoord[] = new double[4];

gl.glGetIntegerv(GL.GL_VIEWPORT, viewport, 0);
gl.glGetDoublev(GL.GL_MODELVIEW_MATRIX, mvmatrix, 0);
gl.glGetDoublev(GL.GL_PROJECTION_MATRIX, projmatrix, 0);

glu.gluUnProject(x, realy, 0.0, mvmatrix, 0, projmatrix, 0, viewport, 0, wcoord, 0);

System.out.println("X = " + wcoord[0] + " , Y = " + wcoord[1] + " , Z = " + wcoord[2]);


models.get(6).draw(glad); //draws the board

gl.glCallList(skyBoxDList); //draws my skybox

for (int i=0 ; i<8 ; i++)
for (int j=0 ; j<8 ; j++)
if (tabuleiro[i][j] != -1) //tabuleiro is the matrix I use to map the board
gl.glPushMatrix(); //push the actual matrix
if (pecaSendoMovida == tabuleiro[i][j])
gl.glTranslated(j * 0.215 + movX * 0.215, 0.0 + movY * 0.215 , -i * 0.215 + movZ * 0.215);
gl.glTranslated(j * 0.215, 0.0 , -i * 0.215); //translates the pieces to the place it's going to be drawn according to my matrix map
models.get(tabuleiro[i][j]).draw(glad); //draws the pieces
gl.glPopMatrix(); //return to the matrix pushed

gl.glFlush(); //execute all commands

If any other code is needed to figure out what I'm trying to do, feel free to ask.

Thanks for the help,

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this