Can anybody tell me how I can transform the following formula into a matrix M with p = Mv? p = l - ((d + n . l) / n . (v - l))(v - l) d is a scalar p, l, n, v are vectors Thanks, Gero PS: This formula calculates a planar perspective shadow onto a plane and is taken from http://www.gdconf.com/archives/proceedings/2001/haines.pdf

What didn''t you understand about my reply the when you asked this question before here. You expand the formula and factor it into a dot product.

I agree with you about the denominator but how exactly do you get the numerator? Please give me a more detailed approach.

Thanks,
Gero

[edited by - gerogerber on June 17, 2002 5:34:28 AM]

Ok, I got it. After some hours of calculating I now understand how to do it

Thanks,
Gero