Clipping with camera in 3D
This is pretty general, but how would I perform camera clipping in a 3d space?
I know how to do it in 2d, but 3d is causing me issues. For 2D clipping, I used the Cohen Sutherland algorithm. Anyone know how I can extend this into 3d?
NOTE:
This is what my projection code is(from 3d to 2d to project onto screen)
var project = function(vert) {
var x = vert[0];
var y = vert[1];
var z = vert[2];
var rY = rotate2d(x - camPos.x, z - camPos.z, camPos.ry * Math.PI / 180);
x = rY[0];
z = rY[1];
var rX = rotate2d(y - camPos.y, z, camPos.rx * Math.PI / 180);
y = rX[0];
z = rX[1];
f = 455 / z;
x = x * f;
y = y * f;
return {x:x,y:y,z:z};
};
In short, what I am trying to do is prevent 'z' from being less than 0(can't just constrain it, that causes problems), as that is what causes everything behind it to go kabloo-y(yes, I have code that checks if three triangle points are behind the camera to prevent drawing in that case). What I currently need is a formula to make 'x' and 'y' what they would be when Z is 0, without overflowing(if that makes sense).
Also, don't worry about rotate2d, that is just a function( I took from here: https://www.youtube.com/watch?v=g4E9iq0BixA
Just assume camera movement I guess(I'm pretty sure I'm confusing you guys).
Thanks in advance!
Figured it out:
var intersect3d = function(vert, vert2) {
var x = vert[0];
var y = vert[1];
var z = vert[2];
var rY = rotate2d(x - camPos.x, z - camPos.z, camPos.ry * Math.PI / 180);
x = rY[0];
z = rY[1];
var rX = rotate2d(y - camPos.y, z, camPos.rx * Math.PI / 180);
y = rX[0];
z = rX[1];
var x2 = vert2[0];
var y2 = vert2[1];
var z2 = vert2[2];
var rY2 = rotate2d(x2 - camPos.x, z2 - camPos.z, camPos.ry * Math.PI / 180);
x2 = rY2[0];
z2 = rY2[1];
var rX2 = rotate2d(y2 - camPos.y, z2, camPos.rx * Math.PI / 180);
y2 = rX2[0];
z2 = rX2[1];
x = x + (x2 - x) * (0.1 - z) / (z2 - z);
y = y + (y2 - y) * (0.1 - z) / (z2 - z);
z = 0.1;
f = 455 / z;
x = x * f;
y = y * f;
return {x:x,y:y,z:z};
};
Anyone can use this without creditting me, though I got some formulas from the video, so maybe credit the creator of itn
