Creating lines at the mid point of existing lines

Replies to This Discussion

Permalink Reply by Raul Matagringo on December 17, 2013 at 1:30am

Hi,

try this one.

I know its not python... However the solution it's shorter.

Hope this helps,

Raul

Attachments:

• mid_2_mid_lines.gh, 7 KB

Permalink Reply by Michelle Frantellizzi on December 17, 2013 at 8:40am

Thanks Raul,

I am mostly trying to learn python. I started to call upon gh components in python but im still working on it.

Michelle

Permalink Reply by djordje on December 17, 2013 at 10:57am

Hi Michelle,

There is even shorter solution in grasshopper:

But for the purpose of further comparison, we will take your initial one, labeled in the following way:

1)get end points from the oldCurves
2)split the starting and ending point lists
3)create lines (lines1, lines2) from previous end points
4)create mid-points of lines1 and lines2
5)create newLines

a) ghpythonlib.components solution:

import ghpythonlib.components as ghc

# 1)get endpoints from the oldCurves
stPts = ghc.EndPoints(oldCurves).start
endPts = ghc.EndPoints(oldCurves).end

# 2)split the starting and ending point lists
stPtsSplit = ghc.SplitList(stPts,1)[1]
endPtsSplit = ghc.SplitList(endPts,1)[1]

# 3)create lines from previous end points
lines1 = []
lines2 = []
for i in range(len(stPtsSplit)):
    line1 = ghc.Line(stPts[i],stPtsSplit[i])
    lines1.append(line1)
    line2 = ghc.Line(endPts[i],endPtsSplit[i])
    lines2.append(line2)

# 4)create mid points of lines1 and lines2
midPtsLines1 = ghc.EvaluateCurve(lines1,0.5)[0]
midPtsLines2 = ghc.EvaluateCurve(lines2,0.5)[0]

# 5)create newLines
newLines = ghc.Line(midPtsLines1,midPtsLines2)

b) rhinoscriptsyntax solution:

import rhinoscriptsyntax as rs

# 1)get endpoints from the oldCurves
stPts = []
endPts = []
for crv in oldCurves:
    stPt = rs.CurveStartPoint(crv)
    stPts.append(stPt)
    endPt = rs.CurveEndPoint(crv)
    endPts.append(endPt)

# 2)split the starting and ending point lists
stPtsSplit = stPts[1:]
endPtsSplit = endPts[1:]

# 3)create lines from previous end points
lines1 = []
lines2 = []
for i in range(len(stPtsSplit)):
    line1 = rs.AddLine(stPts[i],stPtsSplit[i])
    lines1.append(line1)
    line2 = rs.AddLine(endPts[i],endPtsSplit[i])
    lines2.append(line2)

# 4)create mid points of lines1 and lines2
midPtsLines1 = []
midPtsLines2 = []
for i in range(len(lines1)):
    domain1 = rs.CurveDomain(lines1[i])
    nrm1Param0_5 = (domain1[0]+domain1[1])/2
    line1 = rs.EvaluateCurve(lines1[i],nrm1Param0_5)
    midPtsLines1.append(line1)
    domain2 = rs.CurveDomain(lines2[i])
    nrm2Param0_5 = (domain2[0]+domain2[1])/2
    line2 = rs.EvaluateCurve(lines2[i],nrm2Param0_5)
    midPtsLines2.append(line2)

# 5)create newLines
newLines = []
for i in range(len(midPtsLines1)):
    newLine = rs.AddLine(midPtsLines1[i],midPtsLines2[i])
    newLines.append(newLine)
#newLines = ghc.Line(midPtsLines1,midPtsLines2)

Currently there is no documentation on ghpythonlib.components. Probably there will be some in the next few months. On the other hand there is a rhinoscript Primer, and a few tutorials.

I do not think I am competent enough to judge whether or not you need to start with ghpythonlib.components right away. Especially because I am thrilled as well with this new ability, and it's potential.

Please attach your .gh and .3dm files for future topics.

Attachments:

• lines_mid_points_rs_ghc.gh, 16 KB
• lines_mid_points_rs_ghc.3dm, 35 KB