# Questions tagged [geometric-transform]

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### How to peel the labels from marmalade jars using Mathematica?

How can I detect and peel the label from the jar below (POV, cylinder radius, jar contents are all unknown) to get something like this, which is the original label before it was stuck on the jar?
2k views

### Movable text on a curve

Having an arbitrary curve defined as InterpolatingFunction, what is the best way to place a text on this curve? The text generally has two rows, for example: ...
351 views

### Why doesn't Normal[] work on GeometricTransformation?

I have a polygon on which I'm applying a GeometricTransform and I want to get the coordinates of the transformed polygon. ...
9k views

### How to draw a great circle on a sphere?

I apologize for the text description, but new users are not allowed to post images. I want to draw a circle that cuts through the center of a sphere and has an inclination of 15 degrees with the ...
362 views

### Unexpected behavior of GeometricTransformation

Bug introduced in 8.0 or earlier and persisting through 11.2.0 or later I have the following mapping on the complex plane: $$z \mapsto \tau \mu z-1,$$ where $\mu$ is complex, $\tau$ is real number....
383 views

### Removing anomalous points from data

I have two sets of 2d-data points which can be transformed in each other by using a certain transformation function. The problem is that in both data sets there are points which do not have ...
994 views

### Applying non-Affine transforms to 2D polygons with textures

I am trying to create a vanishing point perspective transformation of 2D polygons, for example transforming the red polygon into the blue polygon: ...
279 views

### Plot points shifted (a lot) in output and PNG export but not in PDF export

Bug introduced in 8 or earlier and fixed in 12.0.0 Consider the following code: ...
3k views

### How to map an image to get an illusion of 3D

I would like to distort or map a given JPEG so that it looks 3D when viewed from certain angle, as in this YouTube video. The most interesting part of the video: I usually use conformal mapping (a ...
4k views

### Application of the projection matrix: Removing perspective distortion

I know that there are many posts about image treatment, but I still have trouble with this little challegene. Baisically I want to remove the perspective distorsion form this image: (source: http://...
1k views

### How to get UV mapping of 3D tube

Here is cylinder data: file We can mesh the surface, thanks to lalmei, Belisarius and Simon (link) How to achieve uv mapping from a 3d straight and curved tube? Working code: ...
529 views

### Make a series of points curl

Say I have a series of points that make a straight line... (Fig 1) points = {{0, 0, 0}, {1, 0, 0}, {2, 0, 0}, {3, 0, 0}, {4, 0, 0}, {5, 0, 0}} I can rotate these ...
1k views

### Rotating a contour plot

I am working with some students on transforming conic sections by rotation of axes. I would like to create a simple Manipulate where I plot the before and after ...
403 views

### Weird behaviour when using Scale, Rotate in Graphics

Bug introduced in 8.0.4 or earlier and persisting through 11.2.0 or later (Edited to simplify drawing) I have a drawing of two tangent circles: ...
249 views

### Why BoundingRegion does not work well?

Bug introduced in 8 or earlier and fixed in 12.0.0 The underlying bug is unstable and wrong rendering of Disk[] and Circle[] ...
139 views

### What does the alignment error returned from FindGeometricTransform measure?

FindGeometricTransform returns "the alignment error together with the transformation function." How is the alignment error computed? I ask because if you iterate <...
500 views

### How to transform general Ellipsoid into rotated axis-oriented one?

Recently, I discovered a long-standing bug in the rendering of Disk and Circle primitives after applying ...
642 views

### How to align a poster?

I'd like to crop and transform out the magazine cover so that it is rectangular. I read the docs for ImagePerspectiveTransformation, and here's where I got to. ...
1k views

### Rotate a grid, made up of lines, so that it aligns with the xy axes

While working on an answer for another problem I hit upon one of my own. I took the image given in that question and cleaned it up so that I could detect the grid lines: ...
534 views

### Extracting data from analog screen photograph

I'm using an analog profilometer from the 1970s and need a way to digitize the data and the only way is through a photograph. I've searched but all I could find was how to extract data from computer ...
1k views

### Coordinate system transformation problem (about Euler angle)

This question comes from the work that constructing the general cylinder by the NURBS. I have implemented the point-set $P_1,P_2,\cdots,P_n$ that in the $O-xyz$ plane, now I want to implement the ...
991 views

### Identifying when two graphic objects overlap

I'm designing a small demonstration that helps to visualize the reason behind shaping an electrode that is used to probe a surface: ...
1k views

### Drawing the Pursuit curves

I was reading this post on Filling Space with Pursuit Polygons. I didn't really see where the filling was, but found it quite interesting. Then I saw these pursuit ...
909 views

### Compose many Geometric Transformations for 3D Graphics

I'm struggling to understand what would be a good way to compose several geometrical transformations to create a single TransformationFunction to be applied to a <...
147 views

### How to extrude a tapered shape (starting from a previous answer)

I have a shape given by ...
62 views

### How to get explicit result of geometric transformation? [duplicate]

Seems like this simply rectangle rescale should work and return the exact coordinates of the transformed resulting rectangle (which should be ...
411 views

### Affine transformation of circular arc in 3D

Start with a quarter-circle of radius 1 centered at the origin and lying in the $xz$-plane: arc = ParametricPlot3D[{Cos[t], 0, Sin[t]}, {t, 0, π/2}] I want to ...
374 views

### Projecting a Graphics3D object onto a plane

I would like to project a 3-dimensional cone onto a plane and mark the intersection (which is an ellipse) with a line. I find cone2 by performing a transformation ...
92 views

### Difficulty Displaying an Untransformed and Transformed Graphics3D Object with Show

Update: This bug has been fixed The bug has been fixed and the code below is working in \$Version=12.1.1 for Microsoft Windows (64-bit) (June 19, 2020). Original ...
71 views

### How is the error of FindGeometricTransform calculated? [duplicate]

This question has beeen asked here but was not answered. How is the returned error calculated? I cannot find any information about this in the documentation of ...
702 views

### Plotting in projective space

I am having difficulty figuring out how to plot to projective space. Suppose I have a region which I have plotted such as: ...