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3
votes
2answers
31 views

What's the point of 48 bit colour?

I've read that the human eye can only really decipher around 10 million different colours, so what's the point in technology that uses 48-bit colour, which allows for $2.81\times 10^{14}$ ...
1
vote
0answers
31 views

Rotating a set of points around two fixed points

I have a set of points that are used to draw a shape. I want to rotate this shape without moving its start and end points. I tried to illustrate what I want in the image below (original shape on left, ...
1
vote
0answers
126 views

What is the difference between a R-tree and a BVH?

I've just read about R-Trees: The key idea of the data structure is to group nearby objects and represent them with their minimum bounding rectangle in the next higher level of the tree; the "R" ...
4
votes
1answer
43 views

Point in Polygon Problem: Has anybody invoked the line integral?

Some twenty years prior I was given the task to solve the Point in Polygon problem for a piece of commercial software. I solved it invoking the ray casting algorithm. After a variety of enhancements ...
1
vote
0answers
23 views

Algorithms to convert 2D videos to 3D ones

Are there published algorithms that can convert 2D videos to 3D ones? If there are few published algorithms for this I am also interested to know how the conversion quality is.
1
vote
1answer
56 views

What is the worst case time complexity for intersection tests with BVHs?

This question is in the context of computer graphics. We have a scene with $n$ triangles and a ray. We want to find if the ray intersects any triangle and get the closest one. There is a ...
1
vote
0answers
36 views

Research in realtime computational physics?

I am aware that there is a considerable amount of interest in computational mechanics for simulation of cloth, hair and other elastica, particularly for animation films. The methods developed by ...
3
votes
2answers
59 views

Segmenting a human body point cloud into limbs

I have a human body point cloud taken through a Kinect (v1). Now, I want to segment the point cloud into different parts, namely hands, lower arms, upper arms, torso, upper legs, lower legs, feet and ...
1
vote
1answer
11 views

Probable focal point of a set of rays

Given a set of two-dimensional rays, how can I determine the probable focal area of the rays? For simplicity, assume a circle focal area. Imagine a number of people throwing paper airplanes at a ...
3
votes
1answer
42 views

Image Comparison tuned to Human Perception

Say I have two systems that take the same drawing commands and starts drawing on their respective platforms (i.e. HTML Canvas). After this is done, I want to save and compare these two images to ...
3
votes
1answer
101 views

Why are division/floating points inefficient in comparison to integer addition/multiplication/subtraction?

Why does Bresenham's line algorithm eliminate dy/dx division and the multiplication of that (potentially floating point) number?
-1
votes
1answer
36 views

How do I output a single pixel on the monitor using assembly language? [closed]

I want a low-level understanding of how a pixel is displayed on a monitor. I am guessing that the point at which I want to display a pixel must be modified in the frame buffer, which should be sent ...
1
vote
1answer
145 views

How does the Sutherland-Hodgman Algorithm work?

The following are the Pages-96 and Page-97 of the book Schaum's outline series of Computer Graphics. The algorithm considers several things: (1) Whether the polygon is Convex or Concave. (2) ...
-1
votes
1answer
204 views

Computing the number of squares which are intersected by a line internally

There's a line from (x1,y1) to (x2,y2) in a grid of squares of unit length. Write a program to compute the number of squares which are intersected by the line internally, i.e squares which are only ...
0
votes
2answers
401 views

Google's Deep Dreamer

I was just wondering on a more technical side, if anyone could explain what Google does to create these amazing images from it's deep dream system. Could anyone explain to me in a step by step way, ...
2
votes
1answer
82 views

Most Efficient Method To Determine Triangle Fill Values Based On Corner Values

I have a triangle and the value of the pixel intensity at each of the three corners of the triangle. I want to interpolate to find interpolated pixel intensities for a set of points inside the ...
0
votes
2answers
96 views

How to expand 2D graphic and functions to 3D?

So I have a program that enables the user to draw 2D-objects. To rotate them, to move them, and so on, all in 2D. I want to expand the 2D objects and functions to 3D which I don't expect to be too ...
-2
votes
1answer
62 views

What's the difference between all these terms?

What's the difference between them - Physically based simulation, Physically based animation, Physical simulation for computer animation, Physically based animation for Computer graphics, Physically ...
4
votes
1answer
71 views

What are some interesting applications of the skyline problem?

You are given a set of $n$ rectangles in no particular order. They have varying widths and heights, but their bottom edges are collinear, so that they look like buildings on a skyline. For each ...
3
votes
0answers
20 views

What is the most efficient algorithm for finding the bounding inequalities of a cone given the extremal rays?

Say that I am given a cone, as specified by the extremal rays whose facets form its convex hull, what is the most efficient algorithm that finds the linear-rank inequalities whose intersection defines ...
3
votes
1answer
134 views

Why there is light source?

In ray tracing if we are tracing a ray from camera to the object, then why there is need for light source as in this image and also rays are going towards the light source instead of outgoing from the ...
0
votes
0answers
84 views

Formula for rays in ray tracing

Each time the camera generates a ray, the first task of the renderer is to determine which object, if any, that ray intersects first and where the intersection occurs. This intersection point is the ...
2
votes
0answers
87 views

Algorithm to outline a group of points

I have a set of coordinates, in practice gps coordinates. Some of them are in clusters and some of them are scattered. Which are which is allready determined. Thus I know which ones are in a ...
1
vote
0answers
17 views

Draping data onto an elevation map

I'm looking for a computational method for projecting data from one grid onto another dissimilar grid while preserving the area of the original grid. I'm not quite sure what these methods would be ...
-1
votes
3answers
116 views

Why do I need high fps values in simulations? [closed]

Sometimes I see NVIDIA simulations with an additional information abbreviated "fps". I've figured out that fps stands for frames per second, but isn't it enough to support 25 fps? Why do I need 60fps ...
4
votes
0answers
77 views

Computing average tile size (grid)

I am trying to compute the average cell size on the following set of points, as seen on the picture: . The picture was generated using gnuplot: ...
0
votes
1answer
156 views

Blob detection as Constraint satisfaction problem?

In image processing I have a black and white image which is represented by matrix {0,1}, I have to find blob (a region of connected pixels) in it. I'm confused, can this problem be reduced to ...
0
votes
0answers
120 views

Camera Matching Algorithm

I am trying to understand how camera matching (or match moving) works. I need to build a program that can move the camera in a way to match a 3D object to its projection on an image. For eg. if I had ...
1
vote
1answer
43 views

Is there a way to predict rendering times? [closed]

In purpose of load balancing I need to approximatively predict rendering time my graphics software (in the specific case it's Autodesk Maya) needs to render a task given an input file (.ma/.mb) and ...
-1
votes
1answer
35 views

Why do 3D engines use rectangular projections for the camera perspective?

In most 3d applications, the scene is projected onto a rectangular area. As the field of view increases, you see terrible distortions near the edges of the screen. Why do modeling engines limit ...
3
votes
0answers
108 views

Simplify closed-path points without intruding into the inside of the path

I want to: Simplify a set of points that outlines a closed opaque image on a transparent background. The simplified set of points should not intrude into the closed opaque image. I use a ...
0
votes
0answers
62 views

Computing the cross product using the right-hand rule

My lecturer has given us some slides on how to use the cross product of 2 vectors to calculate their normal. We are told to use the right-hand rule when computing this, however the following image is ...
6
votes
2answers
257 views

What are all the differences between the Gibbs phenomenon artefects and JPEG artefacts?

I thought the Gibbs phenomenom is the result of Fourier analysis estimation (but was it Fourier Series estimation or can it also be Fourier Transform estimation?) JPEG uses the Discrete cosines ...
2
votes
1answer
65 views

Resizing and aliasing in computer science [closed]

If you resize an 1000x1000 raster image to 10x10 and resize it back to 1000x1000 is this considered to be an example of aliasing?
1
vote
1answer
1k views

How does the midpoint line drawing algorithm work?

I'm having trouble understanding the mechanics of the midpoint algorithm. I understand the gist of what it does; it keeps us within a half a pixel of where the actual line should be printed. It does ...
2
votes
0answers
45 views

Stream processor definition

I'm looking for an actual definition of a stream processing unit (SPU), preferably sourced. The context is not specifically graphics cards. I can find many, many articles explaining what they ...
1
vote
1answer
182 views

Sphere, triangle, and other primitive shape intersection

In a three dimensional Cartesian space, given a ray in its parametric form: $r(t) = [1, 1, 1] + t[-1, -1, -1]$ find the intersection points between the ray and the following primitives. a) A sphere ...
3
votes
2answers
290 views

Closing shapes at non-endpoints

Consider how one would represent the following image in vector graphics: Pretty simple, right? The entire shape can be represented by a single path element. But suppose additionally that you want ...
2
votes
1answer
371 views

How to do pixel array rotation whose angle not a multiple of 90 degree?

It is easy to rotate pixel array if the angle is a multiple of 90 degree. For example, (quote from Computer Graphics with OpenGL) We can rotate a two-dimensional object or pattern 90' ...
3
votes
1answer
1k views

What the difference between the Fourier Transform of an image and an image histogram?

Consider this small picture of a sunflower, and its histogram: What would the Fourier transform of the first picture look like? Is there any relationship between the histogram and the Fourier ...
1
vote
1answer
2k views

How do I compute the luminance of a pixel?

I have a color (say $R=100, G=150, B=130$). How do I compute its intensity? Do I just sum up all three components? Or are the colors not evenly weighted?
1
vote
2answers
1k views

Computer graphics: Linear Interpolation

I have two vector points $p_1$ and $p_2$. Each point has a color value $c_1$ and $c_2$. Now using linear interpolation, I would like to get the color value at point $p_3$. Concrete example: $\qquad ...
7
votes
1answer
716 views

Line smoothing algorithm that perserve data uniformity

Intro: I'm working with huge data set that i need to plot in browser, and since there may be up to 1M points my idea was to create different representations for different zoom levels lets say i have ...
1
vote
0answers
72 views

Extreme instancing for computer graphics

Instancing in GPU's, from my little knowledge, simply draw the same object at multiple locations. Each "instance" is just a copy of the same model at a different location. Any local effects, such as ...
6
votes
1answer
242 views

Radon transform for advanced 3d graphics and games?

The Radon transform is used to take 2d projections of an object and create a 3d representation. It seems like it would be possible to apply such a transform in 3d graphics in games (although possibly ...
1
vote
0answers
46 views

A text for virtual environments seminar

What is a good textbook for a seminar about virtual environments, virtual worlds, augmented reality and similar topics? The seminar is at the graduate studies level and is supposed to give ...
4
votes
3answers
383 views

Intuition for convolution in image processing

I have read many documents about convolution in image processing, and most of them say about its formula, some additional parameters. No one explains the intuition and real meaning behind doing ...
9
votes
1answer
606 views

How to find contour lines for Appel's Hidden Line Removal Algorithm

For fun I am trying to make a wire-frame viewer for the DCPU-16. I understand how do do everything except how to hide the lines that are hidden in the wire frame. All of the questions here on SO all ...
10
votes
1answer
427 views

Is the shadow ray in a Whitted ray tracer occluded by transparent objects?

In a Whitted ray tracer, each ray-object intersection spawns a transmitted ray (if the object was translucent), a reflected ray and a shadow ray. The shadow ray contributes the direct lighting ...
16
votes
3answers
707 views

Ray Tracing versus object-based rendering?

Intro graphics courses usually have a project that asks you to build a ray tracer to render a scene. Many graphics students entering grad school say that they want to work on ray tracing. And yet it ...