Computer Graphics Stack Exchange
Computer Graphics Stack Exchange

Questions tagged [cad]

14 questions
10
votes
2 answers

Reliable test for intersection of two Bezier curves

How to reliably find out whether two planar Bezier curves intersect? By "reliably" I mean the test will answer "yes" only when the curves intersect, and "no" only when they don't intersect. I don't need to know what parameters the intersection was…
Ecir Hana
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5
votes
3 answers

Rounding corners of polygon given vertices of its corners

Given a polygon (regular or irregular, convex or concave), I want to round its corner, with a given radius; let's say 'x'. I have the code to draw an arc given 2 points, but how can I find the start and end points of the arc? All I have is a list of…
user3453636
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5
votes
1 answer

How do CAD programs render non-polygonal 3D objects?

How CAD programs handle displaying B-Reps and NURBS/T-Splines in their viewports? Assuming viewport uses OpenGL API - are those programs transform every object into triangles and creating/deleting vertex/index buffers when needed?
pmakal
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4
votes
1 answer

Solving a set of Geometry Constraints - What's that Method called?

I am looking for the correct term for a type of problem solver. Since its hard to google for something without knowing its name, I hope that the good people of this stackexchange may be able to help me. When defining shapes in CAD systems based on…
Rikki-Tikki-Tavi
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3
votes
1 answer

Rounding a corner formed by Arc and Line

Given shapes like these, which contain just Arcs and lines, I want to round all its corners with certain radius. I know the vertices of the lines & arcs these shapes. I can round the corners of a polygon (when two lines meet to form a corner), but…
user3453636
  • 105
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3
votes
2 answers

First steps towards CAD standard curve fitting

I am interested in building a program to accomodate the following workflow: A user begins with an arbitrary vector/CAD shape, which they wish to transfer onto paper without using a printer (there are both realistic and novelty reasons why this…
Will Goldie
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3
votes
1 answer

Normalize NURBS knot vector

I have NURBS surface data. I have a list of control points, knot vectors in U and V params and the degree. The U knot vector lies in range -3.14 to 3.14 and the knot V vector lies in range -100 to 100. How can I normalize this data so that both knot…
Vaibhav
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2
votes
1 answer

Feeding vertex data to a compute shader

I'm writing a CAD program in vulkan. In my current design, I have line paths represented as large vertex buffers for rendering. I would like to implement an algorithm for extruding the path outwards, based off of cross products. Ideally I would like…
Holden Green
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2
votes
2 answers

Clipping circle and polygon and generate a CAD drawing

I'm developing a CAD drawing generator using C# and netdxf library (https://github.com/haplokuon/netDxf) The app first performs boolean operations (specifically - union & subtraction) on polygons and draws the resultant path on .dxf file. I'm using…
user3453636
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1
vote
1 answer

Fill an irregular region with 2D shapes

I am creating a 2D CAD drawing generator in C# using .netDXF library. Given a area I want to fill it with rectangles/circles (convex). For example, the regions marked with numbers in below image. This is just an example, the pattern may change. I'am…
user7413
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1
vote
1 answer

Which geometry file format is the most similar to our geometry file format?

To represent a 3D geometry in our software we use this format below: Material-1 Material-2 P1(X1,Y1,Z1) P2(X2,Y2,Z2) P3(X3,Y3,Z3) This 11 point gives us a triangle with the description of what is behind and front of the triangle. Depicted below: By…
Kutadgubilig
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0
votes
0 answers

Software to obtain high resolution images of a STEP geometry file

When trying to obtain high resolution images of geometry files, the only option seems to take a screenshot of the software in use (Salome, Catia, etc...). Although enough in most circumstances, it seems that it is not possible to take a…
Msegade
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0
votes
0 answers

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 geometries to our internal format. But we also…
Gonzales Gokhan
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0
votes
0 answers

Algorithm to select regions based on curvature on a mesh

I'm trying to understand how to implement an algorithm similar to the one used by Magics' mark surface tool, you can see such behaviour on this video. Quoting the video: "Basically with this tool you're able to select surfaces, which unlike planes,…
user4801