calculation mouseposition to floor

Helper

On 15/02/2014 at 16:35, xxxxxxxx wrote:

Hey,

i looking for a way to calculate - the position on the floor where the mouse is pointing to.

i get the mouse part working and get a x y coordination - but don`t get the way to the coordinates where it break the y 0

  
pickrespos = bd.SW(c4d.Vector(mx,my,distance?))

thanks

Helper

On 24/02/2014 at 08:10, xxxxxxxx wrote:

No one an idea how Calculate the Pointer Direktion to floor ?

Thanks

Helper

On 10/03/2014 at 05:03, xxxxxxxx wrote:

There are many resources for maths online.

import c4d
import random
  
def iszero(x) :
    r""" Returns True if *x* is near zero. """
  
    return abs(x) < 1.0e-07
  
def perpendicular_vector(v) :
    r""" Finds an arbitrary perpendicular vector to *v*. Sort of a lazy
    implementation.. """
  
    a, b = random.random(), random.random()
    if not iszero(v.z) :
        x, y, z = v.x, v.y, v.z
    elif not iszero(v.y) :
        x, y, z = v.x, v.z, v.y
    elif not iszero(v.x) :
        x, y, z = v.y, v.z, v.x
    else:
        raise ValueError('zero-vector')
  
    c = (- x * a - y * b) / z
  
    if not iszero(v.z) :
        return c4d.Vector(a, b, c)
    elif not iszero(v.y) :
        return c4d.Vector(a, c, b)
    elif not iszero(v.x) :
        return c4d.Vector(b, c, a)
  
def describe_line(a, b) :
    r""" Returns a description of a line based on the two
    points *a* and *b* in space. *a* and *b* must not equal. """
  
    assert a != b
    return (a, (b - a))
  
def is_point_on_line(line, p) :
    r""" Checks if the point *p* is element of the specified
    *line*. """
  
    d_a = (line[0] - p).Dot(line[1])
    return iszero(d_a)
  
def describe_plane(a, b, c) :
    r""" Returns a description of a plane based on tree
    points *a*, *b* and *c* in space. *a*, *b* and *c* must
    not equal and *c* must not be on the same line described
    by *a* and *b*. """
  
    assert a != b
    assert a != c
    assert not is_point_on_line(describe_line(a, b), c)
  
    return (a, (b - a), (c - a))
  
def plane_normal(plane) :
    r""" Returns the normal of the *plane*. """
  
    return plane[1].Cross(plane[2]).GetNormalized()
  
def get_plane(name) :
    r""" Returns the description of a plane based on the
    specified *name*. The following values are accepted:
  
    - *XZ*, *ZX*, *floor*
    - *XY*, *YX*, *front*
    - *YZ*, *ZY*, *right* """
  
    name = name.lower()
    if name in ('xz', 'zx', 'floor') :
        n = c4d.Vector(0, 1, 0)
    elif name in ('xy', 'yx', 'front') :
        n = c4d.Vector(0, 0, 1)
    elif name in ('yz', 'zy', 'right') :
        n = c4d.Vector(1, 0, 0)
    else:
        raise ValueError
  
    x1 = perpendicular_vector(n)
    y1 = x1.Cross(n).GetNormalized()
  
    return describe_plane(x1, y1, c4d.Vector(0))
  
def find_intersection(line, plane) :
    r""" Finds the intersection of the *line* and *plane*.
    Returns None if the line does not intersect the plane or
    is element of it. """
  
    n = plane_normal(plane)
    d_a = (plane[0] - line[0]).Dot(n)
    d_b = line[1].Dot(n)
  
    if iszero(d_a) or iszero(d_b) :
        # No intersection or line is part of the plane.
        return None
  
    return line[0] + (d_a / d_b) * line[1]
  
from c4d import Vector as V
line = describe_line(V(100), V(-100))
plane = get_plane('floor')
print find_intersection(line, plane)

Cheers,
-Niklas