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0answers
22 views

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 ...
0
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0answers
7 views

Where on the .obj or .mtl files is the information needed to find the texture associated with a wavefront file?

I've downloaded the sponza scene, and I will use it to develop multi object rendeirng on my engine. I can load the mesh just fine. But the mesh is currently monochromatic (looks 3D thanks to blinn ...
1
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0answers
26 views

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 ...
3
votes
1answer
73 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 ...
1
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2answers
68 views

Convert a .X mesh to a modern format

I have a bunch of meshes in the .X format, which isn't supported by many 3D applications today. Therefore, I would like to convert these to a modern format like fbx or gltf/glb. Since these meshes ...
0
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0answers
19 views

how to draw mesh equal distance from irregular shape geometry bounding box

I am given an irregular geometry shape with its vertices, bounding box information. How to draw a smooth mesh equal distance from that irregular geometry shape's bounding box? Please refer to the ...
1
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0answers
24 views

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 ...
3
votes
2answers
267 views

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 ...
6
votes
1answer
111 views

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, ...
3
votes
1answer
59 views

How to remove internal geometry programmatically in all meshes in .OBJ file?

I have an .OBJ 3D model with many complex meshes shape. The meshes are complex because each of them have multiple internal mesh located in it. Meshes with internal geometry is defined as a mesh, ...
4
votes
1answer
90 views

Triangulation of vertices of an ellipsoid

I have the parametric model of an ellipsoid like this: \begin{cases} x=a_1\,cos \,\eta \:cos\,\omega & -\pi\leq\omega\leq\pi \\𝑦 = 𝑎_2\,cos\,\eta\:sin\,\omega \\ z=a_3\,sin \,\eta & -\frac{...
1
vote
1answer
82 views

What is the algorithm used in pbrt-v3 for triangle intersection?

Where's this algorithm come from? Any references? And a specific question, when the authors compute the transformation from world space to ray-triangle intersection coordinate space, what's the ...
3
votes
0answers
115 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 ...
1
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0answers
36 views

Which vertices to use to create side of model

I hope I'm asking on the right StackExchange site. Apologies if I'm not. I want to generate 3D triangulated models of optical lenses, circular in shape. I can create the meshes for the front and back ...
1
vote
1answer
72 views

Topology: Polygonal Meshes, Euler's Formula

Firstly, I would like to tell this is my first question on stackexchange and I am a senior school student. Please bear with me, if I am not able to express myself clearly. I am trying to solve a ...
1
vote
0answers
94 views

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 ...
2
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0answers
41 views

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 ...
3
votes
1answer
67 views

How do I replace a mesh's texture with vertex colours?

I have a textured 3D mesh. I want to deduce a 3D mesh without texture, but with an RGB vector color on each node of this 3D mesh. The colors have to be picked from the initial texture. Is there a way ...
1
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3answers
102 views

Same specular lighting on both tris in a quad (for “low-poly” “flat shading” look)?

Here's an example of the flat shaded squares I want. But my squares are made of two triangles, and I'm getting flat shading of those triangles. In openGLES 3.1 (android), I'm turning off ...
1
vote
2answers
74 views

How do I do batch conversion (preferably in MATLAB) from .gif images to .off or .stl mesh files? [closed]

I'd like to do a batch converison of 1400 .gif images into .off or .stl format files that'll be meshed images. Two sample .gif images are attached. How can I do this conversion possibly by a free ...
4
votes
2answers
153 views

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) ...
2
votes
0answers
51 views

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 ...
10
votes
3answers
955 views

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 ...
2
votes
1answer
248 views

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 ...
9
votes
3answers
283 views

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 ...
1
vote
2answers
326 views

Extract visible vertices from a 3D geometry model

Let's assume we have a 3D model consisted of XYZ-formatted vertices (such as point cloud model). My problem is given the position and normal of camera or camera ...
2
votes
1answer
106 views

Compute area (not surface area) and perimeter of a mesh

I'm currently researching how to compute geometric properties of architectural shapes based on their 3D meshes, and am stuck for some time on the area and perimeter calculations. First, the area: ...
1
vote
0answers
87 views

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
vote
0answers
39 views

3D sphere mesh with a predefined number of vertices and a given adjacency matrix of vertices

I need a 3D triangular sphere mesh with uniformly sampled vertices, say $V$, with a predefined adjacency. Is there a specific way to achieve that?
5
votes
1answer
128 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 ...
1
vote
0answers
55 views

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 ...
4
votes
0answers
211 views

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 ...
1
vote
1answer
148 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'...
4
votes
1answer
410 views

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 ...
7
votes
1answer
1k views

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 ...
1
vote
0answers
40 views

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 ...
6
votes
1answer
2k views

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 ...
5
votes
1answer
166 views

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
vote
0answers
86 views

In a polygonal mesh 3d model which consist of triangles is it possible to separate different objects?

I have a 3d city model that is a collada file which consist of many triangles. When I select the model in a 3d software all buildings are selected. But I want every building to be selectable ...
5
votes
1answer
55 views

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 ...
5
votes
2answers
218 views

Combination of Triangles and Quads in a mesh

Is it topological correct to combine triangles with quads to form a mesh. If not, why?
4
votes
1answer
183 views

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 ...
5
votes
2answers
112 views

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? ...
7
votes
1answer
318 views

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 ...
8
votes
1answer
178 views

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 ...
1
vote
1answer
436 views

Which 3D algorithms does Windows 10's “3D Builder” application use?

Windows 10 ships with "3D Builder", a Universal App that contains utility functions to prepare STL, OBJ, 3DS, and other files that represent geometries for 3D printing. The utility looks like this: ...
1
vote
1answer
120 views

maximal convex patching in Computer graphics

Given a 3D object in Computer graphics, whose surface is represented as a 3D triangular mesh (mesh of 3D triangle objects), I need to find the maximum continual Convex patches on the surface of the ...
10
votes
3answers
589 views

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 ...
10
votes
1answer
260 views

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 ...
8
votes
1answer
1k views

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 ...