# Thread: Problem with oblique projection derivation

1. Hi,
Can some body plz guide me how the values of xp and yp in case of oblique parallel projection is equal to:

xp= x + L cos (phi)
yp= y + L sin (phi)

This is mentioned in slide 50 of following link:

I have studied that oblique projection is the sum of orthogonal and shear. Orthogonal is same as "x" but i cant understand how we got "L cos(phi)".

I would be glad to hear from some body in this regard.

Zulfi.

2. Drop a line down from (xp, yp) onto the xv axis and call the point (xv, yv)., where xv=px. Then consider the triangle made by the points
(x,y) (xp, yp) and (xv, yv).
Cos phi = (xv -x)/L
Xv=xp =x + Lcos phi

3. Hi
Thanks. Great work. I tried but i didnot find this calculation any where. Just one thing plz correct me:
where xv=px
Should i use Xp instead of px.

Thanks again for this calculation.

Zulfi.

4. Yes!

5. Thanks for your help. I think i am bale to understand all components of this figure. This problem is solved now.

Zulfi.

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