Experimentation with 3d formulae in DOS.
The program demonstrates a cuboid which can be rotated and translated using mentioned keys. The 3d formulae used are:
| Symbols | Meaning |
|---|---|
| objectx, objecty, objectz | point of rotation of object |
| camerax, cameray, cameraz | point of camera looking at the world you make |
| xpos, ypos, zpos | position of pixel in the world coords |
| a, b, c | angles around x, y, z axes |
| xscale, yscale | scale factors for x, y axes |
| xcentre, ycentre | centre of vision on the screen |
| x, y | position of pixel on screen |
x1 = xpos - objectx
y1 = ypos - objecty
z1 = zpos - objectz
y2 = y1*cos(a) + z1*sin(a)
z2 = z1*cos(a) - y1*sin(a)
x2 = x1*cos(b) + z2*sin(b)
z3 = z2*cos(b) - x1*sin(b)
y3 = y2*cos(c) + x2*sin(c)
x3 = x2*cos(c) - y2*sin(c)
rx = objectx - camerax
ry = objectx - cameray
rz = objectz - cameraz
xf = rx + (xscale*x3) / (rz+z3)
yf = ry + (perspy*y3) / (rz+z3)
x = xf + xcentre
y = yf + ycentre
Cuboid in default position (keeps rotating).
Cuboid in moved position (translated, rotated).
