# Create truncated Cone
**URL:** https://discourse.vtk.org/t/create-truncated-cone/813
**Category:** Support
**Created:** [April 22, 2019, 6:53pm UTC](https://discourse.vtk.org/t/create-truncated-cone/813 "2019-04-22T18:53:30Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@siaeleni](https://discourse.vtk.org/u/siaeleni)
#### Post date: [April 22, 2019, 6:53pm UTC](https://discourse.vtk.org/t/create-truncated-cone/813/1 "2019-04-22T18:53:30Z")
Hello,
I want to display a truncated code like the following
Any hint would be appreciated.
Thanks
---
### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [April 22, 2019, 6:59pm UTC](https://discourse.vtk.org/t/create-truncated-cone/813/2 "2019-04-22T18:59:14Z")
You can create any rotationally symmetric shape from a polyline using `vtkRotationalExtrusionFilter`.
---
### Author:  [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)
#### Post date: [April 22, 2019, 9:23pm UTC](https://discourse.vtk.org/t/create-truncated-cone/813/3 "2019-04-22T21:23:13Z")
This example shows how to use the `vtkRotationalExtrusionFilter` to extrude a line segment, so is directly applicable for generating this shape:
[https://vtk.org/gitweb?p=VTK.git;a=blob;f=Filters/Modeling/Testing/Cxx/TestRotationalExtrusion.cxx](https://vtk.org/gitweb?p=VTK.git;a=blob;f=Filters/Modeling/Testing/Cxx/TestRotationalExtrusion.cxx)
---
### Author:  [@amaclean](https://discourse.vtk.org/u/amaclean)
#### Post date: [April 23, 2019, 11:54am UTC](https://discourse.vtk.org/t/create-truncated-cone/813/4 "2019-04-23T11:54:41Z")
Also look at: [CappedSphere](https://lorensen.github.io/VTKExamples/site/Cxx/Modelling/CappedSphere/). You should be able to easily modify the function **GetLine** to do what you want.
---
### Author:  [@Andrew](https://discourse.vtk.org/u/Andrew)
#### Post date: [April 24, 2019, 3:56am UTC](https://discourse.vtk.org/t/create-truncated-cone/813/5 "2019-04-24T03:56:40Z")
I made a vtkTruncatedConeSource with a simple modification of vtkCylinderSource. Just add some getters and setters for Radius1 and Radius2 instead of Radius. And replace the usage of Radius in the top and bot values in vtkCylinderSource.cxx with Radius1 and Radius2 appropriately. Iād post the whole code but vtkCylinderSource.h/.cxx is a lot.
---
### Author:  [@amaclean](https://discourse.vtk.org/u/amaclean)
#### Post date: [April 24, 2019, 6:42am UTC](https://discourse.vtk.org/t/create-truncated-cone/813/6 "2019-04-24T06:42:51Z")
That should work, although creating a line and rotating it would have been simpler.š
---
### Author:  [@amaclean](https://discourse.vtk.org/u/amaclean)
#### Post date: [April 24, 2019, 10:26am UTC](https://discourse.vtk.org/t/create-truncated-cone/813/7 "2019-04-24T10:26:24Z")
Here is a quick example creating a line to rotate to make a truncated cone that you can drop into [CappedSphere](https://lorensen.github.io/VTKExamples/site/Python/Modelling/CappedSphere/) _(the C++ version is easy to create from this, it is left as an exercise for the reader)_.
```auto
def get_line1(height, radius1, radius2, step, uncapped):
"""
Get the points for a line.
The parametric equations for the line are:
x = x1 + (x2 - x1) / t
z = z1 + (z2 - z1) / t
0 <= t <= 1
Conditions:
height > 0
radius2 < radius1
step > 0
:param height: Height of the cone.
:param radius1: Radius of the base of the cone.
:param radius2: Radius of the top of the truncated cone.
:param step: The number of points in each line.
:param uncapped: True if uncapped.
:return: A vector of points.
"""
pts = list()
t = 0
x02 = radius2
z02 = height / 2
if not uncapped:
# Create the cap for radius2
while t < 1:
if t != 0:
x = x02 * t
z = z02
else:
x = 0
z = z02
pt = (x, 0, z)
pts.append(pt)
t += 1.0 / step
# The sloped line for the cone
t = 0
x21 = radius1 - radius2
z21 = height / 2
while t <= 1:
if t != 0:
x = radius2 + x21 * t
z = z21 - height * t
else:
x = radius2
z = z21
pt = (x, 0, z)
pts.append(pt)
t += 1.0 / step
t = 0
x10 = radius1
z10 = -height / 2
if not uncapped:
# Create the cap for radius1
while t < 1:
if t != 0:
x = radius1 - x10 * t
z = z10
else:
x = radius1
z = z10
pt = (x, 0, z)
pts.append(pt)
t += 1.0 / step
return pts
```