I think the original "slope" formulas were written by Damien Jones, though several authors have written derivatives. For an explanation of how to use the slope formulas in standard.ufm, click the red '?' in the Layer Properties window. For the slope formulas in reb.ufm, check http://www.hiddendimension.com/Tutorials/Slope/Slope_Tutorial.html.

I think the original "slope" formulas were written by Damien Jones, though several authors have written derivatives. For an explanation of how to use the slope formulas in standard.ufm, click the red '?' in the Layer Properties window. For the slope formulas in reb.ufm, check http://www.hiddendimension.com/Tutorials/Slope/Slope_Tutorial.html.