Barycentric coordinates in Custom Expression Node

Hello,
Im wondering if someone can help me with the Custom Expression Node. Im not sure why it is not working. Basically Im trying to use it to blend 3 textures together inside a given triangle.
Im my example I broke it down the the smallest components possible.I pass the 3 points of my triangle (a,b,c) and p (vertex position node). I calculate the barycentric coordinates(u, v, w). Then I check if p is inside my triangle by making sure the sum of u+v+w is <=1 (image has typo of * but I use +). If true I return the desired blend weigh (u,v,w) to a Weighted Blend node and a texture index to my texture array.
Im not seeing any affect, I would expect my triangle to have a different color than the surrounding triangles and have a gradient blend.
Please help I not sure if the Nodes are used correctly
Im wondering if someone can help me with the Custom Expression Node. Im not sure why it is not working. Basically Im trying to use it to blend 3 textures together inside a given triangle.
Im my example I broke it down the the smallest components possible.I pass the 3 points of my triangle (a,b,c) and p (vertex position node). I calculate the barycentric coordinates(u, v, w). Then I check if p is inside my triangle by making sure the sum of u+v+w is <=1 (image has typo of * but I use +). If true I return the desired blend weigh (u,v,w) to a Weighted Blend node and a texture index to my texture array.
Im not seeing any affect, I would expect my triangle to have a different color than the surrounding triangles and have a gradient blend.
Please help I not sure if the Nodes are used correctly