Non-Uniform Scale

Geometric definition

A non-uniform scaling is a transformation that changes the size of a geometry by a certain factor for each or some of the axes. The factor can be defined by a number.

How to add

As often is possible in Rhino to use either RhinoCommons or RhinoScriptSynthax to add a point to the Rhino workspace. Here are the two methods:

RhinoCommons

import Rhino.Geometry as rg
import scriptcontext as sc

# create a rectangle
rectangle = rg.Rectangle3d(rg.Plane.WorldXY, 10, 10)

# do a non-uniform scale transformation
scale = rg.Transform.Scale(rg.Plane.WorldXY,  # plane of scaling
                           1,                 # x scale factor
                           2,                 # y scale factor
                           3)                 # z scale factor

# transform the rectangle
rectangle.Transform(scale)

# add the rectangle to the document
sc.doc.Objects.AddRectangle(rectangle)

RhinoScriptSynthax

import rhinoscriptsyntax as rs

# create a rectangle
rectangle_id = rs.AddRectangle(rs.WorldXYPlane(), 10, 10)

# create a scale transformation
scale = rs.Scale(rs.WorldXYPlane(),  # the plane on which to scale
                1,                 # the scale factor in x
                2,                 # the scale factor in y
                3)                 # the scale factor in z

# apply the transformation to the rectangle
rs.TransformObject(rectangle_id, scale)

Main methods and properties

Operators

Non-uniform scaling as all the other transformations have a set of operators that can be used to perform to combine transformations (also different kinds, e.g.: translation with rotation). Here are the main ones:

xform_1 = rs.Scale(rs.WorldXYPlane(), 1, 2, 3)
xform_2 = rs.Scale(rs.WorldXYPlane(), 0.2, 3.6, 4.9)

xform_3 = xform_1 * xform_2 # Will combine the two transformations

⚠️ Note that the order of the transformations is important. In the example above the first transformation will be applied first and the second transformation will be applied second. ⚠️

Properties

Non-uniform scaling as all the other transformations have a set of properties that can be used to retrieve information about the transformation. Here are the main ones:

non_uniform_scale = rs.Scale(rs.WorldXYPlane(), 1, 2, 3)

non_uniform_scale.IsIdentity # Will return True if the transformation is an identity transformation
non_uniform_scale.IsZero # Will return True if the transformation is a zero transformation
non_uniform_scale.IsValid # Will return True if the transformation is valid

🛠 Exercises

Starting file:

01: 🦏⬇️⬇️⬇️ Download the file here ⬇️⬇️⬇️🦏 01: 🐍⬇️⬇️⬇️ Download the script here ⬇️⬇️⬇️🐍

Solution:

01: 🦏⬇️⬇️⬇️ Download the file here ⬇️⬇️⬇️🦏 01: 🐍⬇️⬇️⬇️ Download the script here ⬇️⬇️⬇️🐍