Finding 90 degree angled vertices among selected lines

eric_ma454 · October 2018

Hi all,
My name is Eric Ma, and myself and 3 others represent a subteam of AguaClara Cornell dedicated to using Featurescript to model our plants. We just switched to OnShape, and are new to Featurescript, so we'll probably be showing up on the forums much more frequently. We're excited to learn more about the language, and all help would be greatly appreciated!

Our current project involves inserting elbows into a selection of created pipes. This is a modification off of the current Beam feature, which is being used to model pipes. The current feature takes an input of edges, and creates "beams" from the edges. Our goal is to find all the points within the given selection of edges that have a 90 degree vertex, and insert an elbow of a specific size there. Our current issue stems from finding the specific 90 degree points. We have found all adjacent points with qVertexAdjacent, but the issue is we're unsure how to find that the vertices that only have two lines stemming from it at 90 degrees. Any help would be appreciated, on this specific question or on Featurescript in general.

Best,
Eric Ma
AguaClara Cornell

@ethan_keller924

konstantin_shiriazdanov · October 2018

As i see you need to iterate through a list of given vertices in the loop and for each vertex query its adjacent line edges and check if the number of edges is exactly 2 and if the vectors of edge lines are perpendicular.

so if definition.vertices is a Query of verteces then you get:

normalAdjacentEdges = [];

for vertex in evaluateQuery(context, definition.vertices)

{

var lineEdges =qGeometry( qVertexAdjacent(vertex, EntityType.EDGE), GeometryType.LINE);

lineEdges = evaluateQuery(context, lineEdges);

if (size(lineEdges)==2)

{

var line1 = evLine(..., lineEdges[0]);

var line2 = evLine(..., lineEdges[1]);

if (perpendicularVectors(line1.direction, line2.direction))

normalAdjacentEdges = append(normalAdjacentEdges, lineEdges);

}

MBartlett21 · October 2018

@konstantin_shiriazdanov & @eric_ma454

You may want to use qWithinRadius if they are sketch lines to find adjacent ones.

Example code (Replace variables in BOLD_ITALICS with your variables:

var perpendicularPointsAndLines = [];
var evaluatedVertices = evaluateQuery(context, <b><i>VERTICES</i></b>);
for(var vertex in evaluatedVertices){
    var vertexPoint = evVertexPoint(context, {"vertex" : vertex });
    var lineEdges = evaluateQuery(context, qGeometry(qWithinRadius(<b><i>LINES_FROM_INPUT</i></b>, vertexPoint, TOLERANCE.zeroLength * meter),
         GeometryType.LINE));
    if(size(lineEdges) == 2){
         var d1 = evLine(context, {"edge" : lineEdges[0]}).direction;
         var d2 = evLine(context, {"edge" : lineEdges[1]}).direction;
         if(perpendicularVectors(d1,d2))
             perpendicularPointsAndLines = append(perpendicularPointsAndLines, {"vertex" : vertexPoint,"edges" : lineEdges});
    }
}

ethan_keller924 · November 2018

Another option is to create an array of all the angles between adjacent lines within a constructed path. This feature should work for you!:

FeatureScript 937;
import(path : "onshape/std/geometry.fs", version : "937.0");

annotation { "Feature Type Name" : "FindAngles" }
export const myFeature = defineFeature(function(context is Context, id is Id, definition is map)
    precondition
    {
        // Define the parameters of the feature type
        annotation { "Name" : "Lines or arcs", "Filter" : EntityType.EDGE && (GeometryType.LINE || GeometryType.ARC) }
        definition.edges is Query;
    }
    {
        var path = constructPath(context, definition.edges);
        var nLines = size(path.edges);
        var tangentLines = evPathTangentLines(context, path, range(0,1,nLines));
        var angles = [];
        for (var i = 0; i<nLines-1; i=i+1){
            var angle = angleBetween(tangentLines.tangentLines[i].direction, tangentLines.tangentLines[i+1].direction);
            angles = append(angles, angle);
        }
        print("An array of the angle at each of the points along the selected path: ");
        print(angles);
    });

Finding 90 degree angled vertices among selected lines

Comments

Howdy, Stranger!

Quick Links

Categories