Questions tagged [vector-graphics]
For questions about scalable 2D graphics based on vector operations, as opposed to raster graphics. For example, polygons, Bézier curves and ellipses.
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Performance of vector graphics versus bitmap or raster graphics
Sometimes I use vector graphics, simply because they look just slightly nicer in some cases, and other times, I use bitmap/raster graphics.
I was wondering, are there any significant performance ...
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2
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What is Illustrator's vector rasterization process?
I am currently trying to understand a few things about vector graphics rasterization and the different ways it is implemented in various application types.
I tested and compared a few programs and ...
- 385
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1
answer
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How to calculate matching roundness of two offset rectangles?
I have two rectangles — one with a fill (blue) and one with a stroke (red). The red rectangle is being offset (depending on the stroke width) so that it appears snug and outside the edge of the blue ...
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2
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Finding the angle of any side of a polygon
I'm trying to find the angle it would take for me to rotate a polygon so that a specific side is completely horizontal and on the bottom.
For example, a shape like this:
Needs to be rotated so the ...
- 163
6
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0
answers
342
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scan line conversion
I am going throug the topic scan line conversion where the scan line parallel to the x-axis is put through the intersection test with all the edges of the polygon.
Would there be any large ...
- 1,229
5
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1
answer
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inside and outside region identification from 2D contour
A 3D model is sliced against a plane and the resulting 2D contour is projected onto the plane. I am looking for an efficient algorithm to identify the inside and outside region of the contour. ...
- 1,229
5
votes
1
answer
400
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SVG opengl implementation - strokes overlap on transparency
I am trying to implement svg rendering by opengl using meshes.
In paths with opacity less than 1, the color of overlapping strokes add up.
But it should be like this
the opengl calls are:
...
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5
votes
1
answer
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How can I verify if a selection area is over a shape in SVG?
I'm creating an SVG editor.
I have a simple selection tool that appears when I click and move my mouse from a blank area in my SVG.
My SVG is populated with rectangles that can have a rotation ...
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5
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1
answer
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How to draw an orthogonal graph from its edges and vertices data?
I am writing a software and I need to represent an graph in a orthogonal manner from topological data (vector of edges,vertices and their connectivity data)
Graphs consist of a set of vertices and a ...
- 283
3
votes
2
answers
221
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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 ...
- 33
3
votes
1
answer
418
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Determining the 'outer' subpath in a compound SVG path
The following four SVG paths render the same (using the default fill-rule="nonzero"):
...
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1
answer
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Choosing & Using a Projection Matrix
I'm looking into the graphics pipeline processes and at the moment in particular, perspective projection matrices.
After looking in several different sources, and across the breadth of previous ...
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1
answer
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Determining Vanishing Points of edges of Triangle using given Point
Due to perspective foreshortening, the projections of parallel lines (1D geometric objects) meet in their vanishing point (a 0D geometric object). Higher dimensional geometric objects also has higher ...
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2
votes
1
answer
296
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What are forms of affine transformations?
Please help me tackle the below question:
Explain THREE forms of affine transformations using relevant examples for each case.
The answers I want to see are scaling, rotation and reflection.
- 29
2
votes
1
answer
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Bezier Curve Tool Controlled by Mouse
So I have recently learned about Bezier Curves (quadratic & cubic) and have a thorough knowledge of how they work. In my graphics engine in DirectX I wanted to implement a Bezier Curve Tool ...
- 2,491
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1
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2
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2
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How to get the length of paths in an given font/character
I wan't create some LED-rope text, using some script font, like the following:
For this I need somewhat estimate the needed length of the LED-rope for the given letter (or combinations of letters).
...
- 121
2
votes
1
answer
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Program to make "Pieslice" without using library function?
As we know in C/C++ there is "graphics.h" header file with the help of which we can do graphics programs in C.
There is a function pieslice in that header file,its syntax is:
...
2
votes
1
answer
389
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LoopBlinn Cubic Curve Rendering - Serpentine arteffect
I am trying to implement the Loop-Blinn cubic curve in java using the following source codes GPU-Curve-Rendering and WebCore. Both of them are showing few arteffects and i cannot figure out why. Here ...
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1
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how to build the feature curves of this algorithm?
I hope this is the right group to be able to expose my doubts about the implementation of the algorithm shown in this article. The question I have is how to do the feature curves, what I do not ...
- 121
2
votes
0
answers
36
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How to add HemisphereLight to a simple threejs scene?
I'm trying to add light and see its changes in a simple scene in threejs but no matter the intensity or the color I set for the light, I see no change in a scene. Actually, if I don't include the ...
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Plotting software used in old scientific papers
Does anyone know what software was used in many old scientific papers (please see attached example). I love the clean look of the graph and the typeface.
Thanks.
Graph example
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0
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Vectorizing half tone images
Vectorizing continuous tone images is often met with color palette reduction and visual artifacts. Half-tone images, on the hand, have constant patterns in their tones, which would intuitively lead to ...
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vote
1
answer
158
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adobe illustrator art brush, how does it work?
I want to find out how the art brush in adobe illustrator works.
It looks like it's taking some vector art and applying it to a smooth line.
How can I go about implementing this?
1
vote
2
answers
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Any good sources on advaced/special rasterization algorithms and techniques and theory behind them?
I spent quite some time looking for books on rasterization of vector graphics and related challenges. The best I found is "Raster Tragedy in Low Resolution",which is old and focused on fonts. There ...
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1
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Bresenham's Algorithm not drawing horizontal lines
I'm getting started with graphics and I'm having trouble implementing the Bresenham's algorithm. Now, I know that my implementation is incomplente, but I can't see why it doesn't make horizontal lines(...
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2
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How to make a translation relative to the line ax + by + c = 0, affine transformations
(sorry for my english)
The task:
A triangle is specified. To realize its motion on the basis of mirror reflection with respect to an arbitrary line ax + by + c = 0, the coefficients of which are ...
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1
vote
1
answer
168
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Why inverse of an allignment matrix is the same as its transpose?
$A_{v}^{-1}$ = $A_{v}^{T}$
$A_{v}$ = Allignment matrix that alligns vector v with z axis
$=$\begin{bmatrix}
\frac{\lambda}{|v|} & \frac{-ab}{\lambda|v|} & \frac{-ac}{\lambda|v|} &...
1
vote
1
answer
710
views
Vectorizing to polylines instead of paths
I am trying to implement a shape matching algorithm for vector images discussed in a paper.
The input to the algorithm is a model of 2D shapes defined by contour segments. According to the paper, such ...
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1
vote
1
answer
91
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How do I normalize all pixel values such that all pixel values are 'pulled towards' the mean?
Originally asked in Graphic Design site here (but I don't know how to 'move' a question to another site)
Credit to this guy: Python Tutorials for Digital Humanities - I followed a lot of his ideas, ...
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vote
1
answer
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Matrix form of an open uniform cubic b-spline
I'm trying to find the matrix form for the equation of a cubic b-spline. More specifically, the "middle" part, S_i(t), is pretty straightforward and available everywhere:
...
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1
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1
answer
243
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How to remove elements in PDF/EPS vector graphics which are completely hidden?
I have EPS/PDF figures which contain scatterplots consisting of a lot of dots resulting in files sizes from dozens to hundreds of MBytes. Now, many of the points are completely hidden, so I could ...
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1
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How do you add text dynamically to an image and export it?
Apologize for crossposting, but I posted this in Stack Overflow and thought it might be a better post here.
Recently, Spotify released their 2019 Spotify wrapped web application, which is essentially ...
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vote
1
answer
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Hooke's Law vector form
I'm studying spring model. There is a suggested equation (Hooke's Law vector form) But, I couldn't understand how to derive that equation.
I'm reading 'Computer Animation Algorithms and Techniques ...
- 523
1
vote
1
answer
439
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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 ...
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1
vote
1
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What graphic languages are simpler than SVG for database diagrams? [closed]
This is PNG was exported from Inkscape. I created it manually and used the
connector tool to link tables.
I find the plain SVG for this diagram more complicated than I was expecting so would like to ...
- 111
1
vote
0
answers
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How do freehand vector drawing tools typically decide where to place the control points?
I'm devising an algorithm to take a freehand curve and make a bezier spline from it. I can do this already just fine, but it's a naive implementation that creates about as many bezier curves as there ...
- 142
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vote
0
answers
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How to encode UTF inside an Encapsulated PostScript
Twenty years ago I made a descriptive illustration program whose output was the industrial standard Encapsulated PostScript, which is also compatible with the LaTeX system. In order to write accented ...
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1
vote
0
answers
132
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How to do a scanline fill with a self intersecting polygon?
I have a bezier curve and would like to draw it's stroke. To do that, I planned to approximate the stroke to a polygon and fill it with a scanline algorithm. While I feel confident about implementing ...
- 111
1
vote
0
answers
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How to programmatically extract shape types like circle etc from SVG file path attributes
I have paths in SVG file with d attributes with values like
M 48.75521890547264 45.77014427860697 Q 48.756218905472636
45.77114427860697 50.24875621890547 45....
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0
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How can I convert a shape made out of pixels to vertices
I'm trying to implement the solution to get the minimum dissection into rectangles of a rectilinear polygon.
My shape is made out of pseudo-pixels (different width/height) but for the moment let's ...
- 173
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0
answers
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0
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1
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What are the i,j,k components of a 3d mesh on plot.ly (online)?
A 3d Mesh on plot.ly online graph maker (https://plot.ly/create/#/) takes 3 mandatory variables (X, Y, Z) and 3 optional variables (I, J, K).
I understand that if I want to draw a cube that I then ...
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2
answers
172
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Relative coordinates -- cumulative sum
I have a vertex shader happily producing all the vertices I want for a 2D plot. Now I want to also render a plot of the same data, but each point relative to the previous one, like SVG Paths using <...
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1
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What are applications of 3D geometry to 2D geometry projection and occlusion handling?
As a layperson in the field of computer graphics, I rarely see practical applications of algorithms that take 3D geometry as the input (along with some camera and lighting parameters) and output the ...
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129
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Point a normal vector towards a point in 3D-Space
Given a normal vector in 3D-Space, how can I rotate the vector, such it points to a point in 3D-Space.
I tried couple of ways doing this, which ended up looking completely wrong.
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77
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How to programmatically extract all rectangle shapes from SVG file?
I have a SVG which contains rectangles with other shapes. How can I extract all rectangle details(co-ordinates, height and width)? Find below svg details where I kept only one rectangle for reference.
...
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0
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160
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How to get world coordinates from a 4X4 camera matrix
I have Intel T265 camera which has a camera coordinates system like following diagram:
The camera system has two cameras and the center of the two cameras is the position of the camera system.
The ...
- 101
0
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0
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134
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Changing Coordinate Frames with Affine Transformations
Stuck with this questions could I get some help.
where uA and vA are two orthonormal vectors indicating the two axes, and oA is the origin. Suppose that all three frames of reference shown in ...
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Mathematics in Computer Graphics
Can you please recommend some topic for research work related to mathematics in CG?
(Maybe something like "Affine transformations in CG")
