Ok, so I'm working on a piece of code in java which displays a 3D rotating cube made out of surfaces - which contain three lines - which contain 2 points. So Point3D > Line3D > Surface3D > Shape3D I'm having trouble getting hidden surface removal to work. I'm not bothering with Z-buffering or anything fancy like that just now rather just determining visibility using L.N = |L|.|N|.cos(theta) Where N is the normal vector of the surface and L is the viewpoint vector visible if 0<= cos(theta) <= 1 However it seems to be removing random surfaces and I've been working on this for ages now with no improvement. Anyone have any idea what's wrong / how to fix it? The following code is located in the Surface3D class. L[] is an array of the 3 Line3D objects used to make the surface. Code: public void draw(Graphics g){ float ax = L[1].getSrc().x() - L[0].getSrc().x(); float ay = L[1].getSrc().y() - L[0].getSrc().y(); float az = L[1].getSrc().z() - L[0].getSrc().z(); float bx = L[2].getSrc().x() - L[0].getSrc().x(); float by = L[2].getSrc().y() - L[0].getSrc().y(); float bz = L[2].getSrc().z() - L[0].getSrc().z(); float nx = (ay*bz)-(az*by); float ny = (az*bx)-(ax*bz); float nz = (ax*by)-(ay*bx); float nx2 = nx/(float)(Math.sqrt((double)(nx*nx + ny*ny + nz*nz))); float ny2 = ny/(float)(Math.sqrt((double)(nx*nx + ny*ny + nz*nz))); float nz2 = nz/(float)(Math.sqrt((double)(nx*nx + ny*ny + nz*nz))); float px = L[1].getSrc().x(); float py = L[1].getSrc().y(); float pz = 2000 - L[1].getSrc().z(); float px2 = px/(float)(Math.sqrt((double)(px*px + py*py + pz*pz))); float py2 = py/(float)(Math.sqrt((double)(px*px + py*py + pz*pz))); float pz2 = pz/(float)(Math.sqrt((double)(px*px + py*py + pz*pz))); float CosTheta = (px2*nx2)+(py2*ny2)+(pz2*nz2); if ((CosTheta >= 0)||(CosTheta <= 1)){ System.out.println("here"); L[0].draw(g); L[1].draw(g); L[2].draw(g); } }
