Point Slide SOP

Overview

This sop allows you to slide points along an edge.

Usage

Select a set of edges to slide points along. The direction of the arrow when selecting them will determine which way the points will slide and the point on each edge that doesn't have an arrow is the point that will slide.

This line should be added to your 456.cmd to make sure you can select edges in the viewport:
omsbind -t sop pointslide:group edges "First input" "Select the edges to slide along" 0 1 edge 0 "" 0

info on 456.cmd
hdox://houdini/content/commands/guide/hscript_events.html

Parameters

Group The group of edges along which points will slide.
Type How the dist parameter is interpreted.
Absolute Distance in object coordinate space.
Parametric Parametric distance. 1 means move the point the entire length of the edge.
Dist The distance along the edge to slide point 0 in each edge.
Iterations Instead of sliding the point the distance specified all in one go this will make the process loop round updating the positions of the points in small amounts until the distance is reached. This means that for edge selections that connect to each other you will get a smoother result after the slide. You don't need this unless your edge selections connect up.
Split Points With this option on when points are slid they pull away from the non selected points creating a gap in the geometry. This only works for polygons since you can't make gaps in Nurbs or Meshes
Reverse Reverse the direction of the point slide.  This swaps the start and end point for each edge, and is different to just putting a negative value in the distance.
Soft Radius Move points not in the original edge selection using a soft falloff.
Clamp Split Points If using a soft radius and spliting points turning this option on will stop the points in the split edge from being effected by the falloff.

Local Variables

EDGE Number of the current edge being processed. The number is relative to the group of edges specified in the group field.
PT0 Point number of the current point being slid.
PT1 Point number of the end point of the edge defining the positive slide direction.