SlopeMask

// Slope Mask Shader by Saul Espinosa for Redshift
// This file is licensed under Apache 2.0 license
shader SlopeMask
[[  string help = "Generates a mask based on Slope and direction",
    string label = "Slope Mask" ]]
(
        float Power  = 4.0
        [[
                float min =0.03,
                float max = 100
        ]],
        float Slope = 0.5
        [[
                float min =  0.0,
                float max = 0.9999999
        ]],
        int Direction = 1
        [[
                string widget = "mapper",
                string options = "X:0|Y:1|Z:2",
                int min =  0,
                int max = 2
        ]],
        output color Out = 1.0
)
{
        Out = pow((N[Direction] - Slope) / .5, 1.0 / Power);
}