So we have such situation: In this illustration, the first quadrilateral is shown on the Image Plane and the second quadrilateral is shown on the World Plane. [1] In my particular case the Image Plane has 3 quadrilaterals - projections of real world squares, which, as we know, have same size, lying on the same plane, with same rotat...
I am interested in using shapes like these: Usually a tangram is made of 7 shapes(5 triangles, 1 square and 1 parallelogram). What I want to do is fill a shape only with tangram shapes, so at this point, the size and repetition of shapes shouldn't matter. Here's something I manually tried: I am a bit lost on how to approach this...
Hi again, i want to refine a previous question: How do i project a sphere onto the screen? (2) gives a simple solution: approximate radius on screen = world radius * cot(fov / 2) / Z with: fov = field of view angle Z = z distance from camera to sphere result is in clipspace, apply viewport to get size in pixels Now my problem ...
Hello! I am working on my own 3d engine and have the following question: I have an abstract object, that handles geometry (vertices and faces). It uses internal storage for this geometry, allows editing and my renderer object has a method RenderGeometry. With this design my rendering process includes a geometry caching step. So, rende...
basically I am trying to model some map brushes that have the following format: Each brush defines a solid region. Brushes define this region as the intersection of four or more planes. Each plane is defined by three noncolinear points. These points must go in a clockwise orientation: 1--2-----------------> | 3 | | | | | , Each brus...
So I have such structure: 3 points (X, Y) BAC and knowledge that in real 3d world BAC angle is 90 degrees.So an image would look like that: And what we want to get at first is : than we wanna add some stuff like 2 parallel lines and what I need next is some formula for somehow shrinking image back to its original view but now w...
In my case as input I have such data structures: original image (RGB pixels), objects (squares) with lines crossing points in pixels (x,y) on Image Plane. I have image like this In my particular case the Image Plane has 3 quadrilaterals - projections of real world squares, which, as we know, have same size, lying on the same plane, w...
Trying to make a very simple boolean function that will find whether a line intersects a sphere. This did not seem to be what I want, even though the question was similar: http://stackoverflow.com/questions/910565/intersection-of-a-line-and-a-sphere Also I have tried the algorithms listed at: http://www.docstoc.com/docs/7747820/Inters...
An interesting 2d section is plane that goes through the center of a regular 3d simplex and 2 other points each of which is a centroid of some non-empty subset of vertices. It is defined by two subsets of vertices. For instance {{1},{1,2}} gives a plane defined by 3 points -- center of the tetrahedron, first vertex, and average of first ...
I have a convex polygon P1 of N points. This polygon could be any shape or proportion (as long as it is still convex). I need to compute another polygon P2 using the original polygons geometry, but "expanded" by a given number of units. What might the algorithm be for expanding a convex polygon? ...
I have a mysql database that I'm trying to populate from a text file. The contents of my file look like (as just some examples. there are thousands of rows) 1:GeomFromText('Polygon(0 0, 1 1, 2 2, 0 0)') 2:GeomFromText('Polygon(0 0, 1 2, 2 2, 0 0)') In my schema, the first field is an integer and the second is GEOMETRY I try to load t...
Hi there, I have seen many examples in various programming languages that are using the Douglas-Peucker polyline simplification algorithm to produce a GPolyline to be used on Google Maps. The algorithm, when expressed for polylines on a plan, involves the calculation of the distance between a point and a line (passing through two other ...
I have an array of "lines" each defined by 2 points. I am working with only the line segments lying between those points. I need to search lines that could continue one another (relative to some angle) and lie on the same line (with some offset) I mean I had something like 3 lines I solved some mathematical problem (formulation of wh...
I've been working on this problem for awhile now, and haven't been able to come up with a good solution thusfar. The problem: I have an ordered list of three (or more) 2D points, and I want to stroke through these with a cubic Bezier curve, in such a way that it "looks good." The "looks good" part is pretty simple: I just want the wedge...
Hello, EDIT I don't know is it important, but destination triangle angles may be different than these of source. Does that fact makes transformation non-affine ? (i'm not sure) I have two triangles in 3D space. Given that i know (x,y,z) of point in first triangle and i know vectors V1,V2,V3. I need to find point (x',y',z'). What tra...
Fellow programmers, I know this is a little outside your juridistiction, but I was wondering perhaps if you have time, if you could help me with one "procedure". Not in view of math but what would be the best way to take. This is an airfoil / profile. Usually, profiles are defined with two sets of data. One is the position of mean c...
I know it's not programming question but I thought we could all use the challenge :) Link to diagram Point A is the source of a laser. It is shinned at a single mirror and then reflected to another mirror finally arriving at point B ... see picture. The goal is to find the total distance of all the lines. I am not a student and th...
I want to make a sin func. so here's my code: inline double _cdecl Sin(double Rad) { _asm { fld QWORD PTR [Rad] fsin } } my func works faster(ratio of about 6) than the standard sin. (there are probably some problems in it, but it's enough for me) but if I'll do for example for(int i = 0; i < 1000000; ++i...
I have a set of points which are interpolated with an unknown method, or to be more precise, the method is known but it can be one of the several - it can be polynomial interpolation, spline, simple linear ... - and a line, which, let's for now imagine it is given in the simple form of y = ax + b. For interpolation, I don't know what me...
I have a set of randomly distributed point in a coordinate system and I'm interested in recognising if some of the points form any geometric figures like a square, circle, parallelogram or simple lines. Do exists any libaries or algorithms for recognising patterns? Or maybe some tipps how to program something like that? ...