Adding support for inverse sigmoid interpolation

1 files changed, 7 insertions, 0 deletions

diff --git a/modules/extras.py b/modules/extras.py
index b8ebc619..15de033a 100644
--- a/modules/extras.py
+++ b/modules/extras.py
@@ -150,6 +150,12 @@ def run_modelmerger(primary_model_name, secondary_model_name, interp_method, int
         alpha = alpha * alpha * (3 - (2 * alpha))

         return theta0 + ((theta1 - theta0) * alpha)

 

+    # Inverse Smoothstep (https://en.wikipedia.org/wiki/Smoothstep)

+    def inv_sigmoid(theta0, theta1, alpha):

+        import math

+        alpha = 0.5 - math.sin(math.asin(1.0 - 2.0 * alpha) / 3.0)

+        return theta0 + ((theta1 - theta0) * alpha)

+

     if os.path.exists(primary_model_name):

         primary_model_filename = primary_model_name

         primary_model_name = os.path.splitext(os.path.basename(primary_model_name))[0]

@@ -174,6 +180,7 @@ def run_modelmerger(primary_model_name, secondary_model_name, interp_method, int
     theta_funcs = {

         "Weighted Sum": weighted_sum,

         "Sigmoid": sigmoid,

+        "Inverse Sigmoid": inv_sigmoid

     }

     theta_func = theta_funcs[interp_method]