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Create normals from triangulated surface

Objective I have a 3D face mesh triangulated. I have computed the midpoint of each triangle in the mesh, and I have the normal vector (n1, n2,n3) for each triangle. The objective is to create a 2D ...
Joker's user avatar
  • 111
2 votes
2 answers
98 views

Sampling from k circles with different radii

Description: I would like to sample n_points points from k circles whose radii and centers are given as lists. Note: This is my ...
ThePortakal's user avatar
0 votes
2 answers
257 views

Read coordinates from many files and calculate polygon areas

My goal with this snippet is to create an array of coordinates which in turn is a tuple of 68 elements, area and modified area array for all 10k elements and assign it to the ...
aki's user avatar
  • 824
6 votes
1 answer
875 views

Choosing evenly distributed points from a million points on a sphere

I have \$10^5\$ to \$10^6\$ points on a sphere, and want to choose some points from them which are as close as uniformly distributed as possible. For that reason, I do the following: at each step I ...
John's user avatar
  • 289
6 votes
0 answers
5k views

Cubic spline interpolation in Python from scratch

I implemented the cubic spline interpolation explained in https://en.wikipedia.org/wiki/Spline_interpolation as a Python class. Of course, such an interpolation should exist already in some Python ...
Ivan ZAR's user avatar
6 votes
1 answer
565 views

Searching extreme points of polyhedron

In my Uni, my scientific professor asked me to make some researches about the extreme points of polyhedrals. And I did them. I found that there is still no code in public for searching extreme points ...
Andrey  Lovyagin's user avatar
6 votes
1 answer
86 views

Optimal algorithm to move a a rope from one position to another

I'm an engineer working with a deformable membrane that is attached to actuators. The goal is to move the membrane from one shape to another, without ripping the membrane. This imposes "neighbor ...
Mike's user avatar
  • 161
4 votes
0 answers
706 views

Find the closest parametric values corresponding to a BSpline's control points

On a curve generated by scipy.interpolate.BSpline I want to find the closest parameters relative to each control point, so that the given parametric range is ...
Fnord's user avatar
  • 383
3 votes
2 answers
114 views

Cythonized Sutherland-Hogman algorithm

I want to cythonise the python implementation of the Sutherland-Hogman algorithm. This algorithm updates a list of vertices according to pretty simple rules (being inside or outside an edge, etc.) but ...
jeandut's user avatar
  • 133
7 votes
1 answer
3k views

4-Bar Mechanism Generation

For a school project, I will design and prototype a bicycle brake that uses a four-bar linkage to accomplish its goal. My Python 3 code does this mechanism generation, and implements methods to ...
syb0rg's user avatar
  • 21.8k
5 votes
1 answer
4k views

Applying Laplacian smoothing to vertices in a mesh

I'm totally new in Python and I wrote some code. It is a simple algorithm to smooth objects. I need to find adjacent vertices in mesh and sum their coordinates and after that divide by a number of ...
Pagorek's user avatar
  • 51
5 votes
1 answer
589 views

Clustering points on a sphere

I have written a short Python program which does the following: loads a large data file (\$10^9+\$ rows) where each row is a point on a sphere. The code then loads a pre-determined triangular grid on ...
John's user avatar
  • 289
14 votes
3 answers
15k views

Generate sample coordinates inside a Polygon

I have a Polygon named as poly. I attempted to randomly select 5 coordinate points that lies inside the polygon. ...
Borys's user avatar
  • 241
4 votes
1 answer
262 views

Calculating the distance squared between all vertex-pairs of a number of 2D polygons

I have implemented my code using Cython. It is the current bottleneck in my computations. There are two non-numpy functions involved: calculate_2D_dist_squared ...
bzm3r's user avatar
  • 399
2 votes
1 answer
350 views

Neighbours from point connections

I am working with a mesh of triangles (in 3D, although I doubt it makes a difference). The mesh is given as list of lists, each list containing the indices of the three vertices of a triangle in said ...
John's user avatar
  • 289
4 votes
1 answer
5k views

Calculating the distance between one point, and many others

In my program, I have entities that I call "blobs", because they have a blobby shape. Blobs are polygons. If I have two blobs, then their information array would look like: ...
bzm3r's user avatar
  • 399
4 votes
2 answers
5k views

Calculating if a point is within a polygon, or outside of it

Here is the function (along with its support functions): ...
bzm3r's user avatar
  • 399
7 votes
1 answer
4k views

Calculating "element-wise" the angles between two lists of vectors

Let's say you have two lists of vectors: v1s = [a, b, c] v2s = [d, e, f] I am interested in generating the following result:...
bzm3r's user avatar
  • 399
4 votes
1 answer
1k views

Point in a polygon algorithm

I am implementing a Point in polygon algorithm. Inputs: M, N: size of the matrix poly: a ...
Dzung Nguyen's user avatar
14 votes
1 answer
10k views

Faster computation of barycentric coordinates for many points

I'm just starting to understand the Python syntax and I created a module that does what I wanted, but really slow. Here are the stats of cProfile, top 10 ordered by ...
adrienlucca.net's user avatar