In Google Maps Street View your cursor turns into a rectangular/oval shape as you mouse over different parts of the scene. For example: http://maps.google.com/?q=loc:+Maryland+Ave+at+e.+26th+st+Baltimore+MD+US&ie=UTF8&z=16&iwloc=A&layer=c&cbll=39.319313,-76.618426&panoid=6W2XgkHoGuf6_SKv0LIL9Q&cbp=12,307.06,,...
Let's say I have a fixed number (X) of points, e.g. coordinates within a given plane (I think you can call it a 2-D point cloud). These points should be partitioned into Y polygons where Y < X. The polygons should not overlap. It would be wonderful if the polygons were konvex (like a Voronoi diagram). Imagine it like locations formin...
I have a set of points and I can derive a least squares solution in the form z = Ax + By + C. The coefficients I compute are correct but how would I get the vector normal to the plane in an equation of this form? Simply using A B and C coefficients from this equation don't seem correct as a normal vector using my test dataset. Thanks ...
Hi there, I got a huge problem. I'm stuck there for two weeks now. It's seems pretty simple. I'm creating a plane, mapping a texture to it. After that I bend it, using the bend modifier from as3dmod. Of course the plane got smaller after the bending process. I've tried to calculate the first and last vertices. var sizeAfterBending:...
Suppose I have some 1000 odd points on a plane. Then, what I think could be done is to discard the points that do not affect the radius of the circle in any way - the points through which the convex hull does not pass [using one of the several algorithms]. This leaves us with points that do matter. Now from here on, what can be done to...
Hi All, So i have a set of four points in 3D Space. P1 [0, 0, 0] P2 [128, 0, 0] P3 [0, 128, 0] P4 [128, 128, 0] Which I'm then projecting orthographically to the screen effectively giving me two wireframe triangles in screen space. I now want to map a texture to this "plane" comprised of the two triangles. So i take my square...
I'm trying to find out when a quadratic selection algorithm is faster than a linear selection algorithm. Running some experiments I generated two 3D plots that show the algorithm run times as a function of the input array size and the desired order statistic. Using gnuplot to draw the plot I confirmed that there are cases when the quadra...
I'm using a for loop to cycle through some elements with a starting value (seats on a plane). Here it is: seatNum - Number of seats to be cycled through startSeat - seat to begin cycling I'm calling the function from a form "onsubmit". The problem comes in the for loop when i try and go get elements with an id naming convention of "s1...
Hey math geeks, I've got a problem that's been stumping me for a while now. It's for a personal project. I've got three dots: red, green, and blue. They're positioned on a cardboard slip such that the red dot is in the lower left (0,0), the blue dot is in the lower right (1,0), and the green dot is in the upper left. Imagine stepping ba...
All right, I need to do two things: I need to determine the equation of a line, with the angle given, from a point in 3D space I need to determine the equation of a plane that is perpendicular to that line, and is a set size, with the original line in it's center. I will need the plane's equation to be in a form where, given a new li...
Imagine there is a very very large room in the shape of a hollow cube. There are magic balls hanging in the air at fixed discrete positions of the room. No magic ball has another one exactly above it. If we take an imaginary horizontal plane of infinite area and pass through the cube, how can we be sure that the plane doesn't cut through...
Ok, using Javascript (or something I can easily convert, I know BASIC very well, but a little rusty at C++ and C#) I need to solve this problem/equation: Given the start and endpoint of a line (in x, y, and z) what point on the line satisfies the equation A*x+B*y+C*z=D A, B, C and D are defined, but x y and z are unknowns, but are s...
I have a plane defined by a normal (n) and a distance (d) (from the origin). I would like to transform it into a new system. The long way is like this: 1) multiply distance (d) with normal (n) resulting in a a vector (p) 2) rotate (R) and translate (v) the vector (p) to get (p') 3) normalize (p') to get the normal 4) use another algorith...
Hi Using Opengl ES for Anroid we’re facing a problem when drawing a square with a texture. They look fine from a distance, but when getting close to the model the texture screws up. We believe this is caused by the fact that the model only consists of four vertices: float[] coords = { -1, 1, 0.0f, 1, 1, 0.0f, -1, -1, 0.0f, 1, -1, ...
hello, i have two points in 3D space which have X-coordinates with different signum. so one of them lies definitely on one side of the X-plane and one on the other. now i want to find the intersection of this plane and the line made up by the two points in the most simple and optimized way. i know how to do general line plane intersect...
Ok, So I've tried to make an application which relies on images being scaled by an individual factor. These images are then able to be turned over, but the use of an animation working on the ProjectionPlane rotation. The problem comes around when an image is both scaled and rotated. For some reason it starts bluring, where a non scaled...
Hello, I can easily draw the projection of a 3D set of points onto the plane with normal vector (1,1,1), by using the matrix (-sqrt(3)/2 sqrt(3)/2 0) (-1/2 -1/2 1). I want to do the same thing, but for a projection onto an arbitrary plane with normal vector (a,b,c) instead of (1,1,1). How to find the matrix...
Greetings all, I read 3d grid data (from multiple TIF images) into a structure as follows : typedef struct VolumeData{ int nx; int ny; int nz; unsigned char *data; // size is nx*ny*nz } Now I want to get the plane slices from this 1-D grid data: eg: unsigned char* getXYPlaneStack(VolumeData *vol,int z); I could implement ab...
I have a set of points, drawn by the user. They will be drawing around some objects. I need to somehow turn this set of points into a shape, so I can find the area to detect collisions. An image will clarify: . The best idea I have had so far involves iterating over every pixel determining if it is 'inside' or 'outside' the shape, b...
2D problem: I measure the position of the 3 ends of a triangle in a cartesian system. Now i move the system (triangle) to another cartesian system and measure the position of just two ends. How can I identify the location of the 3rd end based on this data? thanks! (and sorry for the bad english as a second angle) ...