PDA

View Full Version : JOGL correct light and reflection in spheres



iron_guitarist1987
11-30-2013, 10:24 PM
Hi all,

I'm using OpenGL in Java using JOGL. I'm trying to get the lights and reflection correct in my program. I have a big sphere, which I can move the the mouse, that should be a light source (LIGHT0), and smaller spheres bouncing around that should reflect the light. I also need a directional light that I can change the direction using the keyboard

first some colors I defined:


float whitish[] = {0.8f, 0.8f, 0.8f, 1};
float white[] = {1, 1, 1, 1};
float blackish[] = {0.2f, 0.2f, 0.2f, 1};
float black[] = {0, 0, 0, 1}


I create the directional light with



gl.glLightfv(GL.GL_LIGHT1, GL.GL_AMBIENT, blackish,0);
gl.glLightfv(GL.GL_LIGHT1, GL.GL_SPECULAR, white,0);
gl.glLightfv(GL.GL_LIGHT1, GL.GL_DIFFUSE, white,0);
gl.glLightfv(GL.GL_LIGHT1, GL.GL_POSITION, spot_position,0);

spot_position is initially [ 0, 0, 1, 0] but it can change by pressing the keyboard keys. a key press adds 0.05 to a specific component of the position vector, until it reaches 1, then it resets back to -1 (nothing fancy).

The light of the center sphere is:


gl.glLightfv(GL.GL_LIGHT0, GL.GL_POSITION, position,0);
gl.glLightfv(GL.GL_LIGHT0, GL.GL_AMBIENT, blackish,0);
gl.glLightfv(GL.GL_LIGHT0, GL.GL_DIFFUSE, white,0);
gl.glLightfv(GL.GL_LIGHT0, GL.GL_SPECULAR, white,0);

This light's position is always centered inside my big transparent sphere. w component of the position vector is 1.

I have this code to draw the picture in the back



gl.glBegin(GL_QUADS);
gl.glMaterialfv(GL.GL_FRONT, GL.GL_DIFFUSE, white,0);
gl.glMaterialfv(GL.GL_FRONT, GL.GL_SPECULAR, white,0);
gl.glMaterialfv(GL.GL_FRONT, GL.GL_SHININESS, white,0);
// Back Face
gl.glNormal3f(0, 0, 1);
gl.glTexCoord2f(texRight, texBottom);
gl.glVertex3f(rx2, ry1, rz1);
gl.glTexCoord2f(texRight, texTop);
gl.glVertex3f(rx2, ry2, rz1);
gl.glTexCoord2f(texLeft, texTop);
gl.glVertex3f(rx1, ry2, rz1);
gl.glTexCoord2f(texLeft, texBottom);
gl.glVertex3f(rx1, ry1, rz1);

To draw the spheres, I use the following functions:



public void drawtriangle(float[] v1, float[] v2, float[] v3) {
gl.glBegin(GL.GL_TRIANGLES);
gl.glNormal3fv(v1, 0);
gl.glVertex3fv(v1, 0);
gl.glNormal3fv(v2, 0);
gl.glVertex3fv(v2, 0);
gl.glNormal3fv(v3, 0);
gl.glVertex3fv(v3, 0);
gl.glEnd();
}

private void subdivideSphere2(float v1[], float v2[], float v3[], long depth) {
float v12[] = new float[3];
float v23[] = new float[3];
float v31[] = new float[3];
int i;

if (depth==0) {
float[] color= {v1[0]*v1[0], v2[1]*v2[1], v3[2]*v3[2], alpha};
gl.glMaterialfv(GL.GL_FRONT, GL.GL_AMBIENT, blackish,0);
gl.glMaterialfv(GL.GL_FRONT, GL.GL_DIFFUSE, color,0);
gl.glMaterialfv(GL.GL_FRONT, GL.GL_SPECULAR, color,0);
gl.glMaterialfv(GL.GL_FRONT, GL.GL_SHININESS, color,0);
drawtriangle(v1, v2, v3);
return;
}
for (i = 0; i<3; i++) {
v12[i] = v1[i]+v2[i];
v23[i] = v2[i]+v3[i];
v31[i] = v3[i]+v1[i];
}
normalize(v12);
normalize(v23);
normalize(v31);
subdivideSphere2(v1, v12, v31, depth-1);
subdivideSphere2(v2, v23, v12, depth-1);
subdivideSphere2(v3, v31, v23, depth-1);
subdivideSphere2(v12, v23, v31, depth-1);
}


public void drawSphere() {
subdivideSphere2(sVdata[0], sVdata[1], sVdata[2], depth);
subdivideSphere2(sVdata[0], sVdata[2], sVdata[4], depth);
subdivideSphere2(sVdata[0], sVdata[4], sVdata[5], depth);
subdivideSphere2(sVdata[0], sVdata[5], sVdata[1], depth);

subdivideSphere2(sVdata[3], sVdata[1], sVdata[5], depth);
subdivideSphere2(sVdata[3], sVdata[5], sVdata[4], depth);
subdivideSphere2(sVdata[3], sVdata[4], sVdata[2], depth);
subdivideSphere2(sVdata[3], sVdata[2], sVdata[1], depth);
}


My problem is, the small spheres aren't reflecting light at all. They are very bright all the time. I can see a little bit of the light being reflected in the green lines of the cube when I move the big sphere closer to them, but no effect at all to the spheres. Also, I can't see any difference when I move the directional light (LIGHT1). I don't see any reflection on the lines of the cube, the big sphere, small spheres or the picture in the back. PM me if you need to see a screenshot. How can I make my spheres not look like they glow, but make them reflect both the directional light and the light from the big sphere? Any help would be greatly appreciated. Thank you.