Python: Deconstruct a plane into its component parts

Replies to This Discussion

Permalink Reply by David Rutten on October 7, 2014 at 12:20am

BaseP.ZAxis?

Permalink Reply by Nenov Ivo on October 7, 2014 at 12:30am

Thank you very much David !!

I feel so dumb... hehe

Permalink Reply by Nenov Ivo on October 8, 2014 at 2:18pm

Hello everyone, i managed to make the 3d Tree  in python for rhino, it works perfectly but when i try to make it in grasshopper nothing goes out of the python component and i don't know where i'm wrong ?? Maybe i cannot write

a = Main()

Here's the rhino python script and i'm attaching the gh file.

import rhinoscriptsyntax as rs
def Main():
startLine = rs.GetObject("pick line")
ang = rs.GetReal("type angle",33.0)
ang1 = rs.GetReal("type angle",120.0)
gens = rs.GetInteger("how many generation to produce",4)
scale = rs.GetReal("type angle",0.9)
curGeneration = []
curGeneration.append(startLine)
for i in range(gens):
newGeneration = []
for line in curGeneration:
newLines = branch(line,ang/(i+1),ang1,scale)
newGeneration.extend(newLines)
curGeneration = newGeneration

def branch(line, ang, ang1, scale):
startPt = rs.CurveStartPoint(line)
endPt = rs.CurveEndPoint(line)
vec = rs.VectorCreate(endPt, startPt)
vec = rs.VectorScale(vec, scale)
baseP = rs.PlaneFromNormal(endPt, vec)
vec1 = rs.VectorRotate(vec, ang, (baseP.YAxis))
vec2 = rs.VectorRotate(vec1, ang1, (baseP.ZAxis))
vec3 = rs.VectorRotate(vec1, -ang1, (baseP.ZAxis))

endPt1 = rs.PointAdd(endPt, vec1)
endPt2 = rs.PointAdd(endPt, vec2)
endPt3 = rs.PointAdd(endPt, vec3)

line1 = rs.AddLine(endPt, endPt1)
line2 = rs.AddLine(endPt, endPt2)
line3 = rs.AddLine(endPt, endPt3)

return [line1, line2, line3]

Main()

Permalink Reply by Nenov Ivo on October 8, 2014 at 2:23pm

Internalised !!

Attachments:

• 3Dtree.gh, 9 KB

Permalink Reply by Anders Holden Deleuran on October 8, 2014 at 3:05pm

Your main() does not return anything. Hence a will not output anything. Not quite sure what the script is doing, but lets say you wanted to output the string "fooBar" from the output parameter a. This would work:

def main():
    return "fooBar"

a = main()


Hope that helps.

Permalink Reply by Nenov Ivo on October 8, 2014 at 3:14pm

Sorry but i've not understand... 

Here's  the code in the python component:

import rhinoscriptsyntax as rs

def Main():
....curGeneration = []
....curGeneration.append(startLine)
....for i in range(gens):
........newGeneration = []
........for line in curGeneration:
............newLines = branch(line,ang/(i+1),ang1,scale)
............newGeneration.extend(newLines)
............curGeneration = newGeneration

def branch(line, ang, ang1, scale):
....startPt = rs.CurveStartPoint(line)
....endPt = rs.CurveEndPoint(line)
....vec = rs.VectorCreate(endPt, startPt)
....vec = rs.VectorScale(vec, scale)
....baseP = rs.PlaneFromNormal(endPt, vec)
....vec1 = rs.VectorRotate(vec, ang, (baseP.YAxis))
....vec2 = rs.VectorRotate(vec1, ang1, (baseP.ZAxis))
....vec3 = rs.VectorRotate(vec1, -ang1, (baseP.ZAxis))

....endPt1 = rs.PointAdd(endPt, vec1)
....endPt2 = rs.PointAdd(endPt, vec2)
....endPt3 = rs.PointAdd(endPt, vec3)

....line1 = rs.AddLine(endPt, endPt1)
....line2 = rs.AddLine(endPt, endPt2)
....line3 = rs.AddLine(endPt, endPt3)

....return [line1, line2, line3]

a = Main()

My imputs are starLine as a Curve, ang as integer, ang1, integer, gens, integer, scale float

      

Permalink Reply by Javier Vizoso on October 8, 2014 at 4:13pm

import rhinoscriptsyntax as rs

def main():
....curGeneration = []
....curGeneration.append(startLine)
....for i in range(gens):
........newGeneration = []
........for line in curGeneration:
............newLines = branch(line,ang/(i+1),ang1,scale)
............newGeneration.extend(newLines)
............curGeneration = newGeneration
....return curGeneration

def branch(line, ang, ang1, scale):
....startPt = rs.CurveStartPoint(line)
....endPt = rs.CurveEndPoint(line)
....vec = rs.VectorCreate(endPt, startPt)
....vec = rs.VectorScale(vec, scale)
....baseP = rs.PlaneFromNormal(endPt, vec)
....vec1 = rs.VectorRotate(vec, ang, (baseP.YAxis))
....vec2 = rs.VectorRotate(vec1, ang1, (baseP.ZAxis))
....vec3 = rs.VectorRotate(vec1, -ang1, (baseP.ZAxis))
....endPt1 = rs.PointAdd(endPt, vec1)
....endPt2 = rs.PointAdd(endPt, vec2)
....endPt3 = rs.PointAdd(endPt, vec3)
....line1 = rs.AddLine(endPt, endPt1)
....line2 = rs.AddLine(endPt, endPt2)
....line3 = rs.AddLine(endPt, endPt3)
....return [line1, line2, line3]

a = main()

Hey Ivo. You were missing the return statement in the main function.

Permalink Reply by Nenov Ivo on October 8, 2014 at 4:20pm

Hello Javier ! Comment vas-tu ? Thanks for your help but now the ouput gives me just the lines of the iteration i'm puting in the gens imput ? How can i get all the lines at once !?

Permalink Reply by djordje on October 8, 2014 at 4:28pm

Hi Ivo,

As Anders already pointed out your Main function is not returning anything.

It needs to return something, before you reference "a" output to it.

There's a difference between the way rhinoscriptsyntax functions work in RhinoPython and in Grasshopper (that's ghpython component):

In Rhino Python Editor, when calling some rhinoscriptsyntax functions, they return certain geometry, add it to the Rhino document (like lines in this case), and therefor it is automatically visible. In grasshopper (ghpython component) the fact that certain rhinoscriptsyntax function has been called and that it returned a geometry to the Grasshopper document, does not mean that geometry will be visible. You still have to add that geometry to a certain variable/list and then return that list at the end of your function (in case you enclose your code in function(s), which you did in this example). Then assign that returned list to a certain ghpython component output variable. Check the attached file.

If this sounds a bit difficult too grasp, or if I am just terrible at explaining things, you can check the Rhino Python Primer. It has some nice beginner friendly explanations on python basics.

Attachments:

• 3Dtree2.gh, 13 KB

Permalink Reply by Nenov Ivo on October 8, 2014 at 4:51pm

Thank you very much Djordje !!

Ok, i think i've understand... and i've understand also that coding is not easy, not easy at all !! Thanks again i'll check the primer !!

Permalink Reply by Anders Holden Deleuran on October 9, 2014 at 7:38am

Great answer Djordje. Guess mine was a wee bit brief and assuming. Glad you figured it out Nenov :)

Permalink Reply by Nenov Ivo on October 16, 2014 at 7:24am

Hello everyone ! 

I have a big problem trying to understand python... chinese for me.

So i have an inversed tree: every generations it creats 3 new points.

On generation (1) i have 4 points counting the start point.

Generation (2) i have 4 points + (3*3points) = 13 points.

Generation (3) i have 13 points + (9*3points) = 50 points.

But when i bake the python component i have 157 points ? Why ?

What's the logic behind this ?

Also how can i have in a, lists of points according to generations and for exemple in b lines according to generations too ??

Here's the code:

import rhinoscriptsyntax as rs
import random as r
r.seed(seed)

def Main():
....allGenerations = []
....allGenerations.append(startPt)
....curGeneration = []
....curGeneration.append(startPt)
....for i in range(gens):
........newGeneration = []
........for pt in curGeneration:
............ang1 = r.randint(-30,30)
............ang2 = r.randint(90,150)
............ang3 = r.randint(210,270)
............dist1 = r.randint(10,40)
............dist2 = r.randint(10,40)
............dist3 = r.randint(10,40)
............zV = -1
............newPoints = branch(pt, ang1, ang2, ang3, dist1/(i+1), dist2/(i+1), dist3/(i+1), zV)
............newGeneration.extend(newPoints)
............curGeneration = newGeneration
............allGenerations.extend(newGeneration)
....return allGenerations

def branch(pt, ang1, ang2, ang3, dist1, dist2, dist3, zV):
....ptP1 = rs.Polar(pt, ang1, dist1)
....ptP2 = rs.Polar(pt, ang2, dist2)
....ptP3 = rs.Polar(pt, ang3, dist3)

....ptA1 = rs.AddPoint(ptP1)
....ptA2 = rs.AddPoint(ptP2)
....ptA3 = rs.AddPoint(ptP3)

....pt1 = rs.MoveObject(ptA1, [0,0,zV])
....pt2 = rs.MoveObject(ptA2, [0,0,zV])
....pt3 = rs.MoveObject(ptA3, [0,0,zV])

....ln1 = rs.AddLine(pt, pt1)
....ln2 = rs.AddLine(pt, pt2)
....ln3 = rs.AddLine(pt, pt3)

....return [pt1, pt2, pt3]

a = Main()

Thanks for you replies and sorry for my noob questions...

Attachments:

• zaquumListTest.gh, 4 KB

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