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Subject: 
Re: Math Help Needed PLEASE
Newsgroups: 
lugnet.cad.dev
Date: 
Mon, 19 Jun 2000 10:08:42 GMT
Viewed: 
515 times
  
In lugnet.cad.dev, Michael Lachmann writes:
The user can move the move the part in x and y direction (which actual axes
depend on the view-rotation-matrix). I need to know where is the nearest point
on the grid for a given screen point 'PS' [x, y, z] (translated into model
space already)

What do you mean by "translated into model space" ?
Back from World coordinates? By applying inv(VM)?

How can you find a z value for the screen point.
There are many possible values.
(How do you go from 2D to 3D?)

Assuming that you could find a 3D screen point, I think the
easiest way is to transform it back to unrotated grid and simply
round up/down to nearest grid value for, x y and z (independently).
/Lars

I sum. everything now:

Given is a vector 'GRID', a rotation matrix 'RM' (for part and grid), a view-
rotation-matrix 'VM' and a screen point 'PS'.

Searched the snapped screen point 'SPS' which is snapped to the nearest grid
point.

Please help me with that!!!!

Thanks in advance,
  Michael



Message is in Reply To:
  Math Help Needed PLEASE
 
Hy, I'm running into math problems again, after I recogniced whats the problem with the movements in MLCad. Now here is what I would like to do: There is a virtual grid which is bound to a part. The distance of the grid lines is given by a vector (...) (24 years ago, 19-Jun-00, to lugnet.cad.dev)

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