Search Results

Search found 2180 results on 88 pages for 'projection matrix'.

Page 14/88 | < Previous Page | 10 11 12 13 14 15 16 17 18 19 20 21  | Next Page >

• Are CMAttitude and CATransform3D related by rotational matrices?

  - by Alex Stone

  I'm looking at the core motion class CMAttitude, it can express the device's orientation as a 3x3 rotational matrix. At the same time I've taken a look at the CATransform3D, which encapsulates the view's attitude, as well as scaling. The CATransform3D is a 4x4 matrix. I've seen that the OpenGL rotational matrix is 4x4 and is simply 0001 padded in the 4th row and column. I'm wandering if the CMAttitude's rotational matrix is related to CATransform's matrix? Can I use the device's rotation in space obtained via a rotational matrix to transform a UIView using CATransform3D? My intention is to let the user move the phone and apply the same transform to a UIView on the screen. Bonus question: if they are related, how do I transform a CMAttitude's rotational matrix to CATransform3D?

  Read the article

• How can I find out how many rows of a matrix satisfy a rather complicated criterion (in R)?

  - by Brani

  As an example, here is a way to get a matrix of all possible outcomes of rolling 4 (fair) dice. z <- as.matrix(expand.grid(c(1:6),c(1:6),c(1:6),c(1:6))) As you may already have understood, I'm trying to work out a question that was closed, though, in my opinion, it's a challenging one. I used counting techniques to solve it (I mean by hand) and I finaly arrived to a number of outcomes, with a sum of subset being 5, equal to 1083 out of 1296. That result is consistent with the answers provided to that question, before it was closed. I was wondering how could that subset of outcomes (say z1, where dim(z1) = [1083,4] ) be generated using R. Do you have any ideas? Thank you.

  Read the article

• k-means clustering in R on very large, sparse matrix?

  - by movingabout

  Hello, I am trying to do some k-means clustering on a very large matrix. The matrix is approximately 500000 rows x 4000 cols yet very sparse (only a couple of "1" values per row). The whole thing does not fit into memory, so I converted it into a sparse ARFF file. But R obviously can't read the sparse ARFF file format. I also have the data as a plain CSV file. Is there any package available in R for loading such sparse matrices efficiently? I'd then use the regular k-means algorithm from the cluster package to proceed. Many thanks

  Read the article

• matrix = *((fxMatrix*)&d3dMatrix); //Evil?

  - by Xilliah

  I've been using matrix = *((fxMatrix*)&d3dMatrix); for quite a while. It worked fine until my screen turned black and received a bucket of frustration on my desk. fxMatrix contains 4 fxVectors. fxVector used to be 16 bytes, but now it was suddenly 20. This was because it inherited fxStreamable, which added the vTable. So one solution is of course just to not inherit fxStreamable, and leave a comment saying that it must always be 16 bytes and never more. Another solution would be to make conversion functions, and copy the matrix completely. This makes it more secure, but has an impact on the performance. I suppose this is the best idea. Another solution is to not convert at all, and stick to D3DXMATRIX, but this makes the engine inconsistent and I personally really dislike this idea. What is your opinion?

  Read the article

• OpenGL ES 2.0 equivalent of glOrtho()?

  - by Zippo

  In my iphone app, I need to project 3d scene into the 2D coordinates of the screen for some calculations. My objects go through various rotations, translations and scaling. So I figured I need to multiply the vertices with ModelView matrix first, then I need to multiply it with the Orthogonal projection matrix. First of all am on the right track? I have the Model View Matrix, but need the projection matrix. Is there a glOrtho() equivalent in ES 2.0?

  Read the article

• OpenGL's matrix stack vs Hand multiplying

  - by deft_code

  Which is more efficient using OpenGL's transformation stack or applying the transformations by hand. I've often heard that you should minimize the number of state transitions in your graphics pipeline. Pushing and popping translation matrices seem like a big change. However, I wonder if the graphics card might be able to more than make up for pipeline hiccup by using its parallel execution hardware to bulk multiply the vertices. My specific case. I have font rendered to a sprite sheet. The coordinates of each character or a string are calculated and added to a vertex buffer. Now I need to move that string. Would it be better to iterate through the vertex buffer and adjust each of the vertices by hand or temporarily push a new translation matrix?

  Read the article

• planar shadow matrix and plane b value

  - by DevExcite

  I implemented planar shadows with the function D3DXMatrixShadow. As you know, we need plane and light factor to calculate a shadow matrix. The problem is that when I set the plane as D3DXPLANE p(0, -1, 0, 0.1f), the shadows by directional light are correctly rendered, but the shadows by point light are not rendered. However, if I use D3DXPLANE p(0, 1, 0, 0.1f), the situation is reversed, shadows by directional light are not drawn, the shadows by point light are ok. I cannot understand why it happens. Is it normal or am i missing something? Please explain to me why this happens. Thanks in advance.

  Read the article

• Extract derived 3D scaling from a 3D Sprite to set to a 2D billboard

  - by Bill Kotsias

  I am trying to get the derived position and scaling of a 3D Sprite and set them to a 2D Sprite. I have managed to do the first part like this: var p:Point = sprite3d.local3DToGlobal(new Vector3D(0,0,0)); billboard.x = p.x; billboard.y = p.y; But I can't get the scaling part correctly. I am trying this: var mat:Matrix3D = sprite3d.transform.getRelativeMatrix3D(stage); // get derived matrix(?) var scaleV:Vector3D = mat.decompose()[2]; // get scaling vector from derived matrix var scale:Number = scaleV.length; billboard.scaleX = scale; billboard.scaleY = scale; ...but the result is apparently wrong. PS. One might ask what I am trying to achieve. I am trying to create "billboard" 3D sprites, i.e. sprites which are affected by all 3D transformations except rotations, thus they always face the "camera".

  Read the article

• Camera lookAt target changes when rotating parent node

  - by Michael IV

  have the following issue.I have a camera with lookAt method which works fine.I have a parent node to which I parent the camera.If I rotate the parent node while keeping the camera lookAt the target , the camera lookAt changes too.That is nor what I want to achieve.I need it to work like in Adobe AE when you parent camera to a null object:when null object is rotated the camera starts orbiting around the target while still looking at the target.What I do currently is multiplying parent's model matrix with camera model matrix which is calculated from lookAt() method.I am sure I need to decompose (or recompose ) one of the matrices before multiplying them .Parent model or camera model ? Anyone here can show the right way doing it ? UPDATE: The parent is just a node .The child is the camera.The parented camera in AfterEffects works like this: If you rotate the parent node while camera looks at the target , the camera actually starts orbiting around the target based on the parent rotation.In my case the parent rotation changes also Camera's lookAt direction which IS NOT what I want.Hope now it is clear .

  Read the article

• Camera closes in on the fixed point

  - by V1ncam

  I've been trying to create a camera that is controlled by the mouse and rotates around a fixed point (read: (0,0,0)), both vertical and horizontal. This is what I've come up with: camera.Eye = Vector3.Transform(camera.Eye, Matrix.CreateRotationY(camRotYFloat)); Vector3 customAxis = new Vector3(-camera.Eye.Z, 0, camera.Eye.X); camera.Eye = Vector3.Transform(camera.Eye, Matrix.CreateFromAxisAngle(customAxis, camRotXFloat * 0.0001f)); This works quit well, except from the fact that when I 'use' the second transformation (go up and down with the mouse) the camera not only goes up and down, it also closes in on the point. It zooms in. How do I prevent this? Thanks in advance.

  Read the article

• How to transform mesh components?

  - by Lea Hayes

  I am attempting to transform the components of a mesh directly using a 4x4 matrix. This is working for the vertex positions, but it is not working for the normals (and probably not the tangents either). Here is what I have: // Transform vertex positions - Works like a charm! vertices = mesh.vertices; for (int i = 0; i < vertices.Length; ++i) vertices[i] = transform.MultiplyPoint(vertices[i]); // Does not work, lighting is messed up on mesh normals = mesh.normals; for (int i = 0; i < normals.Length; ++i) normals[i] = transform.MultiplyVector(normals[i]); Note: The input matrix converts from local to world space and is needed to combine multiple meshes together.

  Read the article

• Where should i organize my matrices in a 3D Game engine?

  - by Need4Sleep

  I'm working with a group of people from around the world to create a game engine(and hopefully a game with it) within the next upcoming years. My first task was writing a camera class for the engine to use in order to add cameras to the scene, position and follow points in the scene. The problem i have is with using matrices for transformations in the class, should i keep matrices separate to each class? such as have the model matrix in the model class, camera matrix in the camera class, or have all matrices placed in one class/chuck? I could see pros and cons for each method, but i wanted to hear some input form a more professional standpoint.

  Read the article

• How should I organize my matrices in a 3D game engine?

  - by Need4Sleep

  I'm working with a group of people from around the world to create a game engine (and hopefully a game with it) within the next upcoming years. My first task is to write a camera class for the engine to use in order to add cameras to the scene, with position and follow points. The problem I have is with using matrices for transformations in the class, should I keep matrices separate to each class? Such as have the model matrix in the model class, camera matrix in the camera class, or have all matrices placed in one class/chuck? I could see pros and cons for each method, but I wanted to hear some input form a more professional standpoint.

  Read the article

• Visual Studio 2012 Coded UI technology matrix updated!

  - by krislankford

  The Visual Studio 2012 support matrix for Automated UI Testing (Coded UI) has been released by Microsoft and the full post can be found here. Thank you Shubhra! There are a couple of items on the list that you should definitely keep your eye on. The first item is the support for Silverlight 4  and 5. This should make the Silverlight community happy. I would also note the Planned items (blue dot) which are cross browser support and Flash/Java. Happy Coding!

  Read the article

• Matrix camera, movement concept

  - by NoFace

  I was talking to some guy. He said that my movement concept in game is bad. When left or right arrow is pressed I'm scrolling background what makes you feel that player is moving (player's X remains same). So... he told me something about matrix view. I should create all walls and platforms static and scroll only the camera and move player's rectangle. I did a little research in Google, but nothing found. Can you tell me anything about it? How to start? Maybe links, books and resources? My programming language is Java (2d). Thank you!

  Read the article

• How to write basic matrix using row and column differently

  - by kounabg

  #include<stdio.h> #include<conio.h> int main() { int a[3][3],i,j; for(i=0;i<3;i++) {printf("enter the value of row A: ",a[i]); scanf("%d",& a[i]);} for(i=0;i<3;i++) {printf("enter the value of row B: ",a[i]); scanf("%d",& a[i]);} for(i=0;i<3;i++) {printf("enter the value of row C: ",a[i]); scanf("%d",& a[i]);} } ***I did this. I want to convert it into matrix and how can I do it?

  Read the article

• wrong operator() overload called

  - by user313202

  okay, I am writing a matrix class and have overloaded the function call operator twice. The core of the matrix is a 2D double array. I am using the MinGW GCC compiler called from a windows console. the first overload is meant to return a double from the array (for viewing an element). the second overload is meant to return a reference to a location in the array (for changing the data in that location. double operator()(int row, int col) const ; //allows view of element double &operator()(int row, int col); //allows assignment of element I am writing a testing routine and have discovered that the "viewing" overload never gets called. for some reason the compiler "defaults" to calling the overload that returns a reference when the following printf() statement is used. fprintf(outp, "%6.2f\t", testMatD(i,j)); I understand that I'm insulting the gods by writing my own matrix class without using vectors and testing with C I/O functions. I will be punished thoroughly in the afterlife, no need to do it here. Ultimately I'd like to know what is going on here and how to fix it. I'd prefer to use the cleaner looking operator overloads rather than member functions. Any ideas? -Cal the matrix class: irrelevant code omitted class Matrix { public: double getElement(int row, int col)const; //returns the element at row,col //operator overloads double operator()(int row, int col) const ; //allows view of element double &operator()(int row, int col); //allows assignment of element private: //data members double **array; //pointer to data array }; double Matrix::getElement(int row, int col)const{ //transform indices into true coordinates (from sorted coordinates //only row needs to be transformed (user can only sort by row) row = sortedArray[row]; result = array[usrZeroRow+row][usrZeroCol+col]; return result; } //operator overloads double Matrix::operator()(int row, int col) const { //this overload is used when viewing an element return getElement(row,col); } double &Matrix::operator()(int row, int col){ //this overload is used when placing an element return array[row+usrZeroRow][col+usrZeroCol]; } The testing program: irrelevant code omitted int main(void){ FILE *outp; outp = fopen("test_output.txt", "w+"); Matrix testMatD(5,7); //construct 5x7 matrix //some initializations omitted fprintf(outp, "%6.2f\t", testMatD(i,j)); //calls the wrong overload }

  Read the article

• Get last row of many matrices (ASCII text files) and create a new matrix from these rows

  - by nofunsally

  I have over a thousand matrices (6 x 2000, ASCII files, comma delimited) that I generated from MATLAB. I want to get the last row of each matrix / text file and save them in a new matrix / text file. The text files have crazy names so when I load them I can name them whatever. Right now I would do this to achieve my goal: % A = load('crazyname.txt'); % B = load('crazynameagain.txt'); % C = load('crazynameyetagain.txt'); A = [5 5 5; 5 5 5; 1 1 1]; B = [5 5 5; 5 5 5; 2 2 2]; C = [5 5 5; 5 5 5; 3 3 3]; D(1,:)=A(end,:); D(2,:)=B(end,:); D(3,:)=C(end,:); I will create each command (e.g. load, building D step by step) in Excel by combining text cells to create a command. Is there a better way to do this? Could I load / assign the matrices with a name that would better suit them to be used in a for loop? Or is some other MATLAB command that would facilitate this? Thanks.

  Read the article

• Projection matrix + world plane ~> Homography from image plane to world plane

  - by B3ret

  I think I have my wires crossed on this, it should be quite easy. I have a projection matrix from world coordinates to image coordinates (4D homogeneous to 3D homgeneous), and therefore I also have the inverse projection matrix from image coordinates to world "rays". I want to project points of the image back onto a plane within the world (which is given of course as 4D homogeneous vector). The needed homography should be uniquely identified, yet I can not figure out how to compute it. Of course I could also intersect the back-projected rays with the world plane, but this seems not a good way, knowing that there MUST be a homography doing this for me. Thanks in advance, Ben

  Read the article

• nHibernate Linq Projection

  - by Craig

  I am using the version 1.0 release of Linq for nHibernate. When I run the following linq statements I receive the error not a single-length projection: Surname I can find very few references to this on the web and looking into the source it says it should never occur! ClientID is a Int type and Surname is a string. When I comment out all the string fields in the projection and just leave ClientID it runs ok, but as soon as I add surname back it errors. var context = m_ClientRepository.Linq; var result = (from client in context from address in client.Addresses from contact in client.Contacts where client.Surname.StartsWith(surname) && client.GivenName.StartsWith(givenName) && contact.Value.StartsWith(phoneNumber) group client by new { client.ClientID, client.Surname, client.GivenName } into clientGroup select new ClientSearchDTO() { ClientID = clientGroup.Key.ClientID, Surname = clientGroup.Key.Surname, GivenName = clientGroup.Key.GivenName, Address = clientGroup.Max(x => x.Addresses.FirstOrDefault().Address), PhoneNumber = clientGroup.Max(x => x.Contacts.FirstOrDefault().Value) }) .Skip(Paging.FirstRecord(pageNumber)) .Take(5);

  Read the article

• OpenGL ES perspective projection

  - by TimeManx

  I'm having a hard time understanding how glFrustum & gluPerspective work. I understand the concept of perspective projection but the functions aren't behaving how I expect them to. For example, if I set the frustum this way glFrustumf(0, 10, 0, 10, 1, 100) and have a rectangle at points 0, 0, 1, 0, 10, 1, 10, 10, 1, 10, 0, 1 then the rectangle is drawn with its left edge at -5 & right edge at 5, so the left half of the rectangle isn't visible. And if x is translated, I'd expect y to be too. But that doesn't happen either. In whatever examples I've seen, the coordinates for the projection matrix are taken as glFrustumf(-10, 10, -10, 10, 1, 100) but either way, whatever part is shown should be dependent on the rectangle's coordinates, right?

  Read the article

• Web Matrix released

  - by TATWORTH

  Microsoft have now released Web Matrix (and ASP.NET MVC3 if you so inclined!) One signifcant utility is IIS Express which will replace Cassini It is worth noting that SP1 for VS2010 should be out in Q1. Links: http://www.hanselman.com/blog/ASPNETMVC3WebMatrixNuGetIISExpressAndOrchardReleasedTheMicrosoftJanuaryWebReleaseInContext.aspx http://www.hanselman.com/blog/LinkRollupNewDocumentationAndTutorialsFromWebPlatformAndTools.aspx http://arstechnica.com/microsoft/news/2011/01/microsoft-releases-free-webmatrix-web-development-tool.ars I am impressed by the copious tutorials on MVC, which I include below: Intro to ASP.NET MVC 3 onboarding series. Scott Hanselman and Rick Anderson collaboration and Mike Pope (Editor) Both C# and VB versions: Intro to ASP.NET MVC 3 Adding a Controller Adding a View Entity Framework Code-First Development Accessing your Model's Data from a Controller Adding a Create Method and Create View Adding Validation to the Model Adding a New Field to the Movie Model and Table Implementing Edit, Details and Delete Source code for this series MVC 3 Updated and new tutorials/ API Reference on MSDN Rick Anderson (Lead Programming Writer), Keith Newman and Mike Pope (Editor) ASP.NET MVC 3 Content Map ASP.NET MVC Overview MVC Framework and Application Structure Understanding MVC Application Execution Compatibility of ASP.NET Web Forms and MVC Walkthrough: Creating a Basic ASP.NET MVC Project Walkthrough: Using Forms Authentication in ASP.NET MVC Controllers and Action Methods in ASP.NET MVC Applications Using an Asynchronous Controller in ASP.NET MVC Views and UI Rendering in ASP.NET MVC Applications Rendering a Form Using HTML Helpers Passing Data in an ASP.NET MVC Application Walkthrough: Using Templated Helpers to Display Data in ASP.NET MVC Creating an ASP.NET MVC View by Calling Multiple Actions Models and Validation in ASP.NET MVC How to: Validate Model Data Using DataAnnotations Attributes Walkthrough: Using MVC View Templates How to: Implement Remote Validation in ASP.NET MVC Walkthrough: Adding AJAX Scripting Walkthrough: Organizing an Application using Areas Filtering in ASP.NET MVC Creating Custom Action Filters How to: Create a Custom Action Filter Unit Testing in ASP.NET MVC Applications Walkthrough: Using TDD with ASP.NET MVC How to: Add a Custom ASP.NET MVC Test Framework in Visual Studio ASP.NET MVC 3 Reference System.Web.Mvc System.Web.Mvc.Ajax System.Web.Mvc.Async System.Web.Mvc.Html System.Web.Mvc.Razor

  Read the article

• How to reproject a shapefile from WGS 84 to Spherical/Web Mercator projection.

  - by samkea

  Definitions: You will need to know the meaning of these terms below. I have given a small description to the acronyms but you can google and know more about them. #1:WGS-84- World Geodetic Systems (1984)- is a standard reference coordinate system used for Cartography, Geodesy and Navigation. #2: EPGS-European Petroleum Survey Group-was a scientific organization with ties to the European petroleum industry consisting of specialists working in applied geodesy, surveying, and cartography related to oil exploration. EPSG::4326 is a common coordinate reference system that refers to WGS84 as (latitude, longitude) pair coordinates in degrees with Greenwich as the central meridian. Any degree representation (e.g., decimal or DMSH: degrees minutes seconds hemisphere) may be used. Which degree representation is used must be declared for the user by the supplier of data. So, the Spherical/Web Mercator projection is referred to as EPGS::3785 which is renamed to EPSG:900913 by google for use in googlemaps. The associated CRS(Coordinate Reference System) for this is the "Popular Visualisation CRS / Mercator ". This is the kind of projection that is used by GoogleMaps, BingMaps,OSM,Virtual Earth, Deep Earth excetra...to show interactive maps over the web with thier nearly precise coordinates.  Reprojection: After reading alot about reprojecting my coordinates from the deepearth project on Codeplex, i still could not do it. After some help from a colleague, i got my ball rolling.This is how i did it. #1 You need to download and open your shapefile using Q-GIS; its the one with the biggest number of coordinate reference systems/ projections. #2 Use the plugins menu, and enable ftools and the WFS plugin. #3 Use the Vector menu--> Data Management Tools and choose define current projection. Enable, use predefined reference system and choose WGS 84 coodinate system. I am personally in zone 36, so i chose WGS84-UTM Zone 36N under ( Projected Coordinate Systems--> Universal Transverse Mercator) and click ok. #4 Now use the Vector menu--> Data Management Tools and choose export to new projection. The same dialog will pop-up. Now choose WGS 84 EPGS::4326 under Geodetic Coordinate Systems. My Input user Defined Spatial Reference System should looks like this: +proj=tmerc +lat_0=0 +lon_0=33 +k=0.9996 +x_0=500000 +y_0=200000 +ellps=WGS84 +datum=WGS84 +units=m +no_defs Your Output user Defined Spatial Reference System should look like this: +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs Browse for the place where the shapefile is going to be and give the shapefile a name(like origna_reprojected). If it prompts you to add the projected layer to the TOC, accept. There, you have your re-projected map with latitude and longitude pair of coordinates. #5 Now, this is not the actual Spherical/Web Mercator projection, but dont worry, this is where you have to stop. All the other custom web-mapping portals will pick this projection and transform it into EPGS::3785 or EPSG:900913 but the coordinates will still remain as the LatLon pair of the projected shapefile. If you want to test, a particular know point, Q-GIS has a lot of room for that. Go ahead and test it.

  Read the article

• transform a matrix wtih 2 columns into a multimap

  - by Derek

  Hi, I am wondering if there is a way to transform a matrix of 2 column into a multimap or list of list. The first column of the matrix is an id (with possibly duplicated entries) and the 2nd column is some value. For example, if I have to following matrix m<-matrix(c(1,2,1,3,2,4), c(3,2)) i would like to transform it into the following list [[1]] 3,4 [[2]] 2 Thanks, Derek

  Read the article

• In R, how to transform a matrix wtih 2 columns into a multimap like structure

  - by Derek

  Hi, I am wondering if there is a way to transform a matrix of 2 column into a multimap or list of list. The first column of the matrix is an id (with possibly duplicated entries) and the 2nd column is some value. For example, if I have to following matrix m<-matrix(c(1,2,1,3,2,4), c(3,2)) i would like to transform it into the following list [[1]] 3,4 [[2]] 2 Thanks, Derek

  Read the article

< Previous Page | 10 11 12 13 14 15 16 17 18 19 20 21  | Next Page >