# Questions tagged [3d]

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### 3D laplacian operator

I have been unable to find the equivalent of the 5-point stencil finite differences for the Laplacian operator. In 2 dimensions for me it is clear that, using the finite difference method:  \nabla_{...
56 views

### Going From Blender Structure defined by triangles to full 3D mesh (Using GMSH?)

I currently have created a model airplane in Blender by drawing a closed volume with triangular planes. I want to do a FEM calculation on this object, meaning I need a fine 3D tetrahedral mesh of this ...
51 views

### How to get free energy surface of a 3d Ising Spin system using Monte Carlo simulation?

I am doing a Monte Carlo Simulation of the properties of a 3D Ising Spin system. I want to get the free energy surface of the spin system from the simulation. It is a magnetization vs free energy ...
70 views

### Why the magnetisation shows abrupt behaviour for this 3D ising spin system

I am trying to simulate a 3D Ising spin system (+1 & -1) using Monte Carlo Metropolis Algorithm. I want to get different physical quantities from this simulation like magnetization, Average Energy,...
108 views

### Find shortest path around a cylinder represented by 3d triangular mesh

Suppose I have a 3d triangular mesh with the topology of a finite cylinder. Let $C$ be a vertex on that mesh. How can I find the shortest path from $C$ to itself that goes around the cylinder? By ...
45 views

### Algorithm to determine flat surfaces and camera orientation without specialized hardware

Modern augmented reality platforms such as Google's ARCore and Apple's ARKit seem to only operate on mobile devices, I'm guessing, because their underlying algorithms require specialized hardware that ...
57 views

### How to implement register blocking for 3D finite-difference stencil computations

I am in need to optimize the performance of the 3D solver that integrates a system of equations for seismic wave propagation. Unsurprisingly, the function that implements the finite-difference stencil ...
540 views

### 3D contour mesh computation

I have the value of a function in three dimensions, $f(x, y, z)$, which varies smoothly. I would like to compute a 3D mesh where $f(x, y, z)$ has a particular value. Are there algorithms to do this? ...
62 views

### On which software can I simulate landmass collisions?

I need to be able to set the properties of the materials (density, size etc) and see what happens according to laws in Physics when landmasses collide each others, with or without bodies of water, ...
574 views

### Iterative camera calibration - No convergence

I am trying to implement the algorithm from the research paper "Accurate Camera Calibration using Iterative Refinement of Control Points" from Datta et al. Running many iterations does not show a ...
200 views

### Linear Least-Squares Point-to-Plane ICP degenerative case

I'm trying to implement Linear Least-Squares Optimization for Point-to-Plane ICP Surface Registration Paper describes linear approximation for point to plane distance for rigid ICP. This approach is ...
1k views

### Algorithms to extract trajectory lines out of 3D point clouds

I am looking for different approaches to extract 3D polylines out of Point Clouds. We are able to create these point clouds out of different data sources of real world surveys (LIDAR, RADAR, etc...) ...
334 views

### What would be a good, fast, way to interpolate a point in 3D space

So I have a 3D mesh made of elements with eight nodes, 12 sides per cell, and in the course of my simulations, I would have to interpolate data from those nodes onto a point inside the cell with a ...
130 views

### How to handle 2D and 3D models efficiently

My coworkers and I have developed a c++ library implementing a "3D Geological Model" class. Goal of this library is to provide a data structure that is used in computational codes (such as Finite ...
128 views

### Data cloning into 3D matrix

I am working with MATLAB, and I would have the following problem. I have the following matrix of random numbers rand(200,200) and I need to create a 3D matrix ...
453 views

### 3-dimensional plotting with nonuniform grids

I have 3 variables I am considering: time (t), 1-dimensional space (x), and intensity (I). I would like to plot the intensity in the z-axis as a function of t and x (the latter two variables would ...
487 views

### Lid-driven Cavity benchmark in 3D. Classical paper to compare

I'm looking for a benchmark for the lid-driven cavity problem in 3D to compare the results of my code. In 2D I used: U. K. N. G. Ghia, K. N. Ghia and C. T. Shin (1982) High-Re solutions for ...
628 views

### Fitting orthogonal planes to a point set

I have a set of 3d points to which I want to fit two planes. I know the assignment of points to the planes so I don't need any RANSAC or similar. Currently, I'm using a PCA-based approach to fit two ...
157 views

### Is model-view-controller useful pattern useful to build scientific simulation programs?

I work with scientific simulation, but what I like the most in programming is creating graphical user interfaces and 2D or 3D outputs to visualize the evolution of the simulations. I know most input ...
617 views

### Iterative Closest Point Algorithm

I am currently working on an iterative closest point algorithm (in C++, see here). I understand the basic premise of an ICP algorithm. You have two point clouds (a target and a reference) and you ...
113 views

### Reducing oscillations a 3D Alternating direction explicit scheme for the diffusion equation?

Hi I have made a 3D alternating direction explicit scheme for solving the diffusion equation, which will eventually replace a FTCS scheme in model of bubble dynamics in tissue. I have been testing it ...
316 views

### Rotate 2D shape around origin in a 3D space

I have a 2D square ABCD in a 3D space, with side length 2s, that is represented by four vectors (one for each vertex) and a fifth vector ...
4k views

### Plot a surface from data sets in MATLAB

I tried to plot a surface in MATLAB but, since it is the first time I had to do something like this, I need a confirmation on the process I followed because it is important for my project to plot the ...
91 views

### Best place to start learning Stereophotogrammetry

Firstly I would like to achieve a final goal as can be found in the links below: Link 1 Link 2 Now I started doing a little bit of research and found that Stereophotogrammetry is the field I should ...
169 views

### Simulate aerodynamics of a general shape object

I'm trying to code a simple physics simulator in C++ but I'm stuck on the air resistance issue. Surfing the Internet I only find a drag coefficient for very basical area shapes when the air is ...