bm_raytrace.py 文件源码

def render(self, canvas):
        fovRadians = math.pi * (self.fieldOfView / 2.0) / 180.0
        halfWidth = math.tan(fovRadians)
        halfHeight = 0.75 * halfWidth
        width = halfWidth * 2
        height = halfHeight * 2
        pixelWidth = width / (canvas.width - 1)
        pixelHeight = height / (canvas.height - 1)

        eye = Ray(self.position, self.lookingAt - self.position)
        vpRight = eye.vector.cross(Vector.UP).normalized()
        vpUp = vpRight.cross(eye.vector).normalized()

        for y in xrange(canvas.height):
            for x in xrange(canvas.width):
                xcomp = vpRight.scale(x * pixelWidth - halfWidth)
                ycomp = vpUp.scale(y * pixelHeight - halfHeight)
                ray = Ray(eye.point, eye.vector + xcomp + ycomp)
                colour = self.rayColour(ray)
                canvas.plot(x, y, *colour)