Questions tagged [mesh]
Questions about a network of connected vertices, edges and faces to describe the shape of a specific 3D object.
168
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What is the simplest way to compute principal curvature for a mesh triangle?
I have a mesh and in the region around each triangle, I want to compute an estimate of the principal curvature directions. I have never done this sort of thing before and Wikipedia does not help a lot....
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4
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Why do T-junctions in meshes result in cracks?
I have heard from many sources that having T-junctions in 3D meshes is a bad idea because it could result in cracks during rendering. Can someone explain why that happens, and what one can do to avoid ...
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5
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Why are quads used in filmmaking and triangle in gaming?
In film school, in the classes of 3D modeling, I was told that when we model something for films we maintain topology of 4 edged polygons. Any polygon which has more or less than 4 edge/vertex is ...
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2
answers
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How to Calculate Surface Normals for Generated Geometry
I have a class that generates a 3D shape based on inputs from the calling code. The inputs are things like length, depth, arc, etc. My code generates the geometry perfectly, however I am running into ...
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14
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2
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Why smoothed meshes in 3D studio end up with the same number of vertices/triangles? How then can they be smoothed with the same geometry?
I am trying to understand why meshes that are smoothed in 3D studio (Modifiers/Smoother) end up having the same amount of vertices/faces before or after that process, as well as the exact same ...
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13
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2
answers
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Programmatically generating vertex normals
I'm working with Kinect face api, it provides an array of vertices and indices for triangles which is to be rendered to make the face image.
The no of vertices and their order in array as well as the ...
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12
votes
1
answer
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What is the benefit of using Half Edge over Winged Edge?
For mesh representation, what is the benefit of using Half Edge over Winged Edge data structure?
I understand both mesh representations, the only difference is that half edge uses directional edge ...
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11
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3
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Ordering a set of unorganized points along a curve
I have a set of 3D points (which I recover from a library that performs the tessellation of a solid body) that belong to a curve (i.e., an edge of the solid). That means that the curve surely passes ...
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11
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3
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How can I perform a triangle inside test in polygon meshes?
I have 3 vertices (V1, V2, V3) randomly selected on a regular triangle mesh. For these 3 vertices, I have computed the geodesic distance and the path (by using ...
- 233
10
votes
1
answer
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Gaussian blurring a function defined over a surface mesh
I have a scalar function defined over the vertices of a surface mesh. I want to compute an approximate (and generalized, I suppose) "Gaussian blur/convolution" of this function over the surface.
I ...
- 205
10
votes
1
answer
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Creating shared vertex normals on GPU
I've mostly succeeded at porting an implementation of Marching Cubes from CPU over to OpenGL compute shaders, but I haven't tackled normals yet and wondering the best way to go about it.
My ...
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10
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1
answer
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Optimal memory access when using lookup tables on GPU?
I'm exploring isosurface algorithms on GPU for a bachelor's project (specifically concentrating on just binary in/out voxel data rather than real-valued fields). So I have a CPU implementation of good ...
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10
votes
1
answer
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Pipeline to create Voronoi Meshes
I would like to implement a Maya plugin (this question is independent from Maya) to create 3D Voronoi patterns, Something like
I just know that I have to start from point sampling (I implemented the ...
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9
votes
2
answers
7k
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How can I convert signed distance field to a mesh?
I can easily make models by Modeling with Distance Functions but I need make mesh from It so I decide to use voxelizing and make triangles for my signed distance field torus like this video.but I ...
9
votes
0
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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8
votes
1
answer
279
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Human Readable/Writable 3D Representation Formats/Languages?
My goal is to create 3D meshes without the use of a 3D editor. So I want to know what representation languages and formats there are that are designed for this or otherwise that would be good for ...
- 181
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votes
1
answer
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Creating a mesh from a point cloud?
I'd like to create a mesh from a point cloud generated by video tracking, ideally using python for some kind of prototype at least.
Initially I thought this is a fairly easy task, connecting the ...
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7
votes
1
answer
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After a deformation operation on polygons, how can I check for and fix inverted polys?
I'm doing a quick and dirty automated deformation routine on a polygon body. If it was a tree, and my axis was in the center of the tree, I would like to bend the body by bending the axis. I would ...
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6
votes
1
answer
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Existing method to automatically fill in this sort of concavity in meshes?
I am working with a PWP3D-like algorithm that renders silhouettes of a mesh in order to segment a frame of video and update an object's pose. Because it is only the silhouettes of the mesh that matter,...
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6
votes
1
answer
409
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How to decompose a complex mesh to simple geometry shape programmatically?
I have a complex geometry mesh object, which is an irregular shape.
I want to redraw that complex geometry mesh object using multiple simple primitive shapes.
For example, I want to use cuboid, ...
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5
votes
2
answers
4k
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Generate mesh from pointcloud data
Given point-cloud data :
For example.
position + color and normal.
What will you use to generate mesh of this data
and keep reasonable quality for real time cases ?
Additional info to consider:
...
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5
votes
1
answer
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Questions about Preconditioning Conjugate Gradient method in Baraff & Witkin 98?
I encountered some problems when implementing the cloth simulation algorithm from Baraff & Witkin 98's Large Steps in Cloth Simulation.
Baraff & Witkin 98
Consider the cloth as a particle ...
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4
votes
2
answers
698
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Combination of Triangles and Quads in a mesh
Is it topological correct to combine triangles with quads to form a mesh. If not, why?
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2
answers
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Should you measure mesh complexity in triangles or vertices?
I have seen people using either vertices or triangles as a quick heuristic to estimate mesh memory usage and mesh rendering time.
I always thought vertices were better, because the number of vertices ...
- 1,594
4
votes
1
answer
855
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How to calculate volume of any given 3D mesh
Given 3D mesh with a closed surface. (solid object without hole).
I'm looking for an algorithm to calculate its volume.
There are several ideas, Such as
Voxelized and count voxels
Point cloud and ...
- 143
4
votes
2
answers
4k
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How to determine the object-to-world matrix
I want to ray trace a triangular mesh that I load from a file. The vertices' coordinates are expressed in the reference frame associated with the object (i.e the mesh) and I don't know the object-to-...
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4
votes
2
answers
240
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Creating a Smooth 3D Mesh from a 2D Outline
I am trying to find (or maybe create) an algorithm for creating a smooth, rounded 3D mesh given a 2D outline. I'm trying to recreate a system from a Gamecube game called Amazing Island, and you can ...
4
votes
1
answer
966
views
Best way to remesh a quad 3D mesh?
I have a quad-based 3D mesh. I want to:
remesh it while keeping the shape the same
the end output should be in quads
ideally it should have a similar number of verts / polys as the input
ideally the ...
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4
votes
1
answer
499
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exact down sampling and re-triangulation of mesh data(non-convex)
I have a human body 'surface' mesh data.: triangular mesh (vertices, face)
What I want to get from this is 'exact-down-sampled' version of the current mesh.
Which means.. the processed output mesh ...
- 41
4
votes
1
answer
133
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Gradient descent (Not ML) on arbitrary meshes
So I am doing a gradient descent like algorithm on the surface of a mesh and I just noticed something:
The above is the geodesic gradient (the distance to a single vertex)
Look at where the ear ...
- 1,594
4
votes
1
answer
200
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Saving a mesh and textures into a single file
I'm looking for a format where I could store a triangle mesh and multiple textures into a single file. Most formats only reference an external file for textures. I found that the FBX format should ...
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4
votes
1
answer
245
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Surface fairing, implementation detail
I'm reading through Polygon Mesh Processing, section 4.3 (Surface fairing).
The reference I mentioned defined defines "Surface Fairing" as
The goal of surface fairing is to compute shapes that are ...
- 496
4
votes
1
answer
430
views
What is better to use for real-time computing Mesh - Plane intersection points, GPU or CPU?
I want to write plugin (library) for Unity3d (it doesn't matter which framework I will choose for this, question is ), for cutting arbitrary mesh with plane (for simplicity it will be plane for ...
4
votes
1
answer
842
views
Calculating Skeleton-Deformed Mesh Normals
I'm implementing mesh skinning in a project of mine. I can calculate vertex positions based on bone transformations, but I've run into a problem with calculating their normals.
From the resources I'...
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4
votes
1
answer
213
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Weird rendering in rectangle mesh shader AKA Why has my basic shader become a modern art generator?
I am trying to translate an old (2013) bit of code from Apple from objective C to Swift with some modifications I need for my simulation.
The code I am translating can be found here
To make ...
- 1,445
4
votes
1
answer
608
views
Degenerate case of normal computation in marching cubes
I'm implementing the marching cubes, reference is this. I managed to get the geometric reconstruction (the mesh) however I do struggle with the normals.
In section 4 they explain the gradient can be ...
- 496
4
votes
2
answers
332
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Implement own Bend function
I'm trying to write a mesh deformer that bends a Cube around an axis like this:
The bend degree in figure A is 90 and something like 35 in B. So if I know my desired bend degree how can I get alpha?
...
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4
votes
1
answer
116
views
Reducing artificial rings in mean curvature of mesh
I have an isosurface/mesh (generated via marching cubes) of a micro-CT scan. Originally the surface looks very noisy, which becomes prevalent when the mean curvature is visualized:
To reduce the ...
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4
votes
1
answer
475
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Algorithm to map a triangular mesh onto plane preserving angles and distances from one vertex
I have a 3D triangular mesh representing cortical surface of a brain. I also have one vertex of interest. I would like to unfold a neighborhood of this vertex in such a way that both the angles (their ...
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4
votes
1
answer
74
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get partial view points from 3d surface mesh
I have a 3d surface mesh.
Say the camera is located in some points and I want to get the visible points from the 3d surface mesh from the camera view.
I believe this kind of process would be done ...
- 41
4
votes
0
answers
76
views
Distributed Mesh Processing with Hadoop [closed]
Is there a library to do mesh processing (slicing, repairing, etc.) on big models in a distributed way using Hadoop?
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3
votes
3
answers
6k
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How can I get a signed distance (SDF) from a mesh?
I am trying to use constructive solid geometry (CSG) and boolean operators to combine various shapes and get the outer (possibly concave) hull. This seems to work okay when using primitive shapes like ...
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3
votes
1
answer
144
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Why is the valence of regular vertices 6?
So I recently learnt that supposedly for any mesh, and pretty much any scheme, the valence of regular vertices must be 6. It seems to be related to the Euler-Poincare formula but I have not been able ...
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3
votes
2
answers
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What is the difference between a "meshlet" and just a small mesh?
Obviously, conceptually, a meshlet is just a small mesh. But what is the reason for making the distinction then? I'm assuming it has to do with how they are implemented.
In a meshlet architecture, ...
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3
votes
1
answer
292
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Smooth triangular mesh interpolation
I am looking for an algorithm which would smoothly interpolate triangles of a mesh (computed by Delaunay triangulation) where each vertex has some value (elevation in my case). I need it for PDAL ...
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3
votes
1
answer
1k
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Most efficient way to render many OO meshes in OpenGL
I am writing a large 3D game in Java with OpenGL.
Question #1
As of now, I am rendering my 3D objects using a Model class that I defined. This class contains vertex,...
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3
votes
1
answer
231
views
How to subdivide faces with a half edge DS?
Assume we have a mesh represented as a half edge datastructure.
We want to subdivide faces without introducing unnecessary vertices (i.e the new number of vertices must be exactly V + E where V is the ...
- 1,594
3
votes
1
answer
296
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Mesh Simplification Algorithms
I'm currently looking into Mesh Simplification to batch-simplify a large amount of .obj files. It is necessary for these algorithms to preserve the visual representation of a mesh as well as possible. ...
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3
votes
2
answers
568
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Fuse detailed road mesh with regular grid terrain mesh
I am experienced with C++ and know more embedded device related stuff but have absolutely no knowledge of computer graphics and its algorithms.
I would like to get a road mesh (based off of a spline) ...
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3
votes
1
answer
2k
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Bevel/Chamfer algorithm for arbitrary 3D mesh
I can't find any paper about a bevel/chamfer algorithm for 3D mesh. Bevel has a lot of special cases (corners, different bevel profile, bevel larger than a face). I am looking for robustness.
Do you ...
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