Questions tagged [mesh]
Questions about a network of connected vertices, edges and faces to describe the shape of a specific 3D object.
63
questions with no upvoted or accepted answers
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3D mesh segmentation simple algorithm
I am developing the algorithm reported in this article:
Least square conformal mapping.
Here is presented an algorithm to flat a 3d mesh on the parametric space, but i don't understand the ...
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445
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Watertight Mesh Representation
A watertight mesh is one which does not have holes, and for which each face has a designated inside and outside. Such a mesh can be "tetrahedralized", has a defined volume, and can be an ...
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What expectations should I have of large (> 2 GB) file support in common mesh workflow tools?
I have an experimental workflow that involves very finely subdivided meshes, above the 2 GB limit where signed 32-bit integers stop working, which often causes problems for various tools. I would need ...
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How can you avoid thin triangles in a parametric shape in a smart way?
I have created a closed 3D mesh using a parametric function. The shape is constructed by taking an arbitrary closed b-spline and scaling it based on one of the parameters (similar idea to a parametric ...
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51
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Stitching 2 boundaries together
Let us say we have 2 boundaries of 2 meshes that are roughly aligned, for example 2 generalized cylinders (sweeping surfaces) with a small gap in between. And let us say we want to connect them to ...
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54
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Divide mesh according to level of detail
Background
I need to remesh by OpenVDB, like what Blender remesh does:
Voxel
Uses an OpenVDB to generate a new manifold mesh from the current geometry while trying to preserve the mesh’s original ...
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2
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48
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Wrapping a point cloud skeleton with a mesh
Using Unity I've been producing sculptural forms that look like this. It's made of patterns of cubes that twist around each other. I'm trying to get it into a 3D printable format.
From unity I export ...
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2
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1
answer
636
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Difference between a spherical camera and a trackball camera
A spherical camera is pretty easy to define.
We have an anchor point C the camera always looks at and a relative position P where the camera is, which can be expressed in spherical coordinates, ...
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611
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Recreate geometry from normal map
I have a group of low polygon meshes, with associated normal maps. The normal maps were created by baking from high polygon meshes, which I no longer have access to. Is it possible to recreate ...
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610
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HalfEdge data structure in openmesh, create_face function explanation
Does anyone have experience with open-mesh or computational geometry and can kindly explain what exactly happens in the function below?
...
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2
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120
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How to model braids?
Many hair simulations render their hair as lines (usually splines). Since hair is a really thin object.
if the hair is braided, rather than having thin infinitesimally small cylinders, you have ...
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157
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Triangle-based and vertex-based skinning models?
I'm reading the Loper et al. 2015 paper on the Skinned Multi-Person Linear Model and I came across this:
What we would like is a vertex-based model that has the expressive
power of the triangle ...
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122
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Algorithm for 3D mesh model segmentation to chart
I'm trying to implement a segmentation model which will divide a 3d mesh model into charts. But I'm having really hard time to find resources in the web. The papers and some other places these ...
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58
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Piecewise smoothing of a mesh?
Kobbelt et al. published a paper some 20 years ago where they specified how solving Poisson equations on the positions of a mesh lead to removing noise. This can be used for reconstructing mesh ...
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How to transform face mesh?
We can use ARcore to create custom textures and 3D models for Augmented Faces, like the augmentation of a Fox ears. But aside from augmenting 3D objects, can we "transform" facemesh, for ...
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How to find point on mesh at a minimum distance from ray
I'm searching for an efficient data structure and algorithm to compute the minimum distance between a ray and a set of meshes in 3D.
What I expect as a result are the coordinates of the nearest point ...
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1
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0
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55
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LOD/culling algorithms with procedural meshes
I am experimenting with procedural meshes. Those are generated at runtime in a compute shader. I'm getting to the point where those geometries are big enough to require some sort of culling/LODing ...
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1
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0
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38
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Geodesic triangle strip algorithm
I think somewhere in the literature there is an algorithm that, given 2 points on a triangle mesh, finds the triangle strip through which the geodesic passes, but I cannot find it anywhere.
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Geodesic approximation algorithms for minimal geodesic curvature
Introduction
I am building an application in which given a surface and a pair of points on it, an analytic expression of some geodesic arc (preferably the one with the shortest length), between them ...
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0
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97
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Given a mesh, a point on the mesh, a direction and a distance, compute the face+barycentric coordinates of point at that geodesic distance
I am a beginner at graphics. I am given a triangular mesh (assume a manifold mesh). I want to sample a square on a mesh that is independent of the triangulation.
I am following these steps
Sample a ...
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1
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0
answers
118
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Problem calculating tangent space
I am currently writing a 3D rendering engine for educational purposes. In general everything is working except that I am chasing down a problem in my cube mesh / tangent calculations that I can't find....
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0
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28
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What algorithms are needed to map displacement to base mesh?
By given belows,
Base mesh(vertices, faces, texture coordinates - UV map),
Normal map(1024x1024 image),
Displacement map(1024x1024 image),
I want to make a mesh which reflects the displacement map. ...
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1
vote
0
answers
218
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Apply transformation to single vertices in OpenGL in order to deform mesh
I'm making a 2D cell simulation game.
The mesh for my cell is basically just a manually-generated triangle fan that looks like this.
I would like to reproduce the wobbling/vibration effect on the ...
1
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0
answers
68
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Question about simple estimation of the discrete curvature at vertices of a mesh
In this post, Nathan-Reed gave a simple, neat, "heuristic" estimation for the discrete curvature at vertices of a mesh.
In a nutshell, it computes a curvature along each edge incident to the vertex, ...
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0
answers
180
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How to render multiple shaders per mesh
I've tried looking everywhere, but I just don't get it. How is multiple shaders assigned to a mesh if you can only bind a single shader in OpenGL?
Assume I have a mesh with a texture shader and now I ...
1
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0
answers
35
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Boundary Smoothing Algorithms
I have a 2-manifold with boundary, built with marching cubes. Are there any well-known algorithms for smoothing its boundary edges?
Most of the papers I found are concerned with smoothing the surface....
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0
answers
145
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Application of parallel transport in computer graphics and mesh processing
Does anyone know what applications has the computation of a parallel transport on a mesh?
I'm talking about methods such as this one
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1
vote
0
answers
185
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fastest way to bucket triangles into a grid?
What is the fastest known method for bucketing triangles into an unbounded regular 3D grid?
Specifically, I need an array of buckets. Random queries (which bucket is here) are not necessary, as this ...
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1
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40
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Proper design of data structure to store wavefront file information?
Currently I have a naive Mesh data structure to store wavefront files.
This data has 3 buffers for the vertices, normals and UVs. It works well to the point I can render the sponza scene, despite ...
- 1,696
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answers
41
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How are non-triangular wavefront meshes handled?
I have a wavefront loader, however it only works with triangular meshes.
I have been trying to think how to handle faces with arbitrarily many vertices but I have no idea how they are to be handled ...
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1
vote
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answers
46
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contract mesh based on mean curvature?
I need to contract(offset) a mesh by a small amount(around 5mm), the mesh itself is quite big (say, 1000mm). The problem is that, I need to contract it based on local mean curvature. That is, for ...
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1
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360
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Octahedral mapping for Spherical functions
I guess most of you are familiar with environment maps, they represent distant lighting distribution, and are used to render objects given their BRDF or SVBRDF distribution. Many papers map the ...
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168
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How do you get edge flow information from mesh
Below there are two identical meshes, however the first one has edges moving in random directions, the second one has edges moving in a orderly, uniform fashion (edge flow).
i want to be able to ...
1
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0
answers
98
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Advice on synthetic data generation using 3D mesh
I'm developing a deep learning algorithm to find and classify (post consumption) plastic bottles on a conveyor belt. A way to train my model is to get tons of labeled images of each bottle, which for ...
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0
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50
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Aligning similar surface meshes consistently
When I have a plaster cast of a mandibula and rest it upside down on a table, in most cases it will be in a stable position.
In real life, I do not have a plaster cast, but a 3D scan, i.e. a surface ...
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1
answer
69
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Constructing half-edges table from triangle list without hash
Motivation
I am trying to refine a mesh such that each triangle gets subdivided into 4 triangles, but I want the vertices to be shared. For that purpose I need a half-edge data structure so I can ...
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34
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Can STEP files contain polygon data? How do I get a smoother mesh out of a STEP file?
I am trying to work with a .STEP file I have received. Upon opening it in CAD Assistant, I find
its surface as jagged lines, like a low poly model. When I export it as OBJ from there, the edges and ...
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How can I understand the logic of Fast Point Feature Histograms (FPFH) descriptor?
I have been using FPFH features quite a lot in global registration and key-point extraction a lot, I also looked pcl page that tries to explain what it is, but fails to give detail to reader in my ...
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23
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Volumetric mesh processing: impact of facet removal on connectedness?
I am working with volumetric meshes - meshes that have vertices (0-cell), edges (1-cell), facets (2-cells) and volumes (3-cells) - and I'm interested in removing facets without breaking connectedness.
...
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0
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49
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Floating point precision in 3d modeling software
I'm working on a simple 3d modeling application. I'm using 1 meter as unit of measurement. When working with small triangles where an edge length is around 1 centimeter (0.01 units) or less, I started ...
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2
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89
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How to extract region inside a loop on sphere
The input is a sphere(defined by radius and center) and a loop defined by a set of points(unordered, illustrated in cyan in the image above) that satisfy the implicit function of the sphere. How can I ...
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22
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Meshing a set of boundaries?
Say I have a set of closed curves in 3D. I want to connect them together into a 2D manifold mesh.
Something kinda like the drawing, where you are making a triangle mesh that is manifold an connects ...
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55
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How would you represent a mesh with tris and quads?
My understanding is that, while subdivision algorithms like Catmull-Clark can work for any polygonal mesh (including triangles) it's preferable to start with a quad mesh.
Currently my rendering engine ...
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42
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Robust convex hull in 3D?
I implemented gift wrapping in 3D, but I am finding it's just AWFUL at handling anything with coplanarity.
I have spent the entire day trying to fix kinks. Naively I thought that if I detected ...
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How can we represent a self-intersecting surface without analytic expression in computer?
Suppose we have a suface without self-intersection, then we can store it numerically using grid samples from its signed distance funtion. But what for the self-intersecting case, can we still use the ...
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70
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ray triangle mesh intersection triangles inverted
I'm trying to render a dodecahedron triangle mesh and the triangles seem flipped or mirrored somehow. The first picture is what I should be getting, the second picture is what I'm getting and the last ...
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136
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Methods to interpolate between 2 topologically identical 3D meshes
I have 2 3D surface meshes. These meshes have vertex-correspondence and have the same topology (same edges and triangles connecting the vertices). However, the vertex positions (3d coordinates) are ...
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Cad ingesting SDK that supports STEP , Parasolid and Solidworks filetypes and Also Meshing
We have an internal CSG (Constructive Solid Geometry) format.Converting/Ingesting other CSG-based files to our internal format is straightforward. We also managed to convert some polygon (mesh) based ...
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150
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Is there any open source code available for simplification of tetrahedral mesh?
I am currently working on tetrahedral meshes and I want to downsample the mesh using techniques like Qslim but there is not much about tetrahedral meshes in the literature. I try to use it as a ...
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108
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How can I render a triangle mesh at 10bit (or 12bit or 16bit) channel depth color?
For a vision research experiment, I have a monitor that supports 10bit/channel (=30bit color). I want to render a triangle mesh in a simple scene that uses the full bit depth, and I want to save this ...
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