Search Results

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

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 17/88 | < Previous Page | 13 14 15 16 17 18 19 20 21 22 23 24  | Next Page >

  • Problems with 3D transformation - (SharpDX)

    - by Morphex
    First of all , I have been trying to get this right for a couple of day already, I have read so much info and still fail miserably to understand this. So I am going to tell you that even though I have done fairly amount of research myself, I failed to implement it. I must say miserably I am trying to create a generic camera class for a game engine of sorts - for research purposes only - the thing is I have no idea how to go about it. I have read about quaternions and matrices, but when it comes to the actual implementation I suck at it. Sharpdx has already Matrices and QUaternions implemented. SO no big deal on the map behind it. How in the world would I go about creating a camera? I have seen so many camera examples and still can't make one that works as expected. I would like to implement diferent types too (Orbital, 6DoF, FPS). So what is need for a camera? UP, Forward and Right vectors I read they are needed, also a quaternion for rotations, and View and Projection matrices. I understand that a FPS camera for instance only rotates around the World Y and the Right Axis of the camera. the 6DoF rotates always around their own axis, and the orbital is just translating for set distance and making it look always at a fixed target point. The concepts are there, now implementing this is not trivial for me. Can anyone point me on what am I missing, what I got wrong? I would really enjoy if you could give a tutorial, some piece of code, or just plain explanation of the concepts. Thank you for readin, a frustrated coder.

    Read the article

  • LINQ to Entities Projection of Nested List

    - by Matthew
    Assuming these objects... class MyClass { int ID {get;set;} string Name {get;set;} List<MyOtherClass> Things {get;set;} } class MyOtherClass { int ID {get;set;} string Value {get;set;} } How do I perform a LINQ to Entities Query, using a projection like below, that will give me a List? This works fine with an IEnumerable (assuming MyClass.Things is an IEnumerable, but I need to use List) MyClass myClass = (from MyClassTable mct in this.Context.MyClassTableSet select new MyClass { ID = mct.ID, Name = mct.Name, Things = (from MyOtherClass moc in mct.Stuff where moc.IsActive select new MyOtherClass { ID = moc.ID, Value = moc.Value }).AsEnumerable() }).FirstOrDefault(); Thanks in advance for the help!

    Read the article

  • Build Interactive Floor With Projection !?

    - by Synxmax
    Dear Guys I am somehow newbie and sometimes guru , but at this moment i don't have enough time to research My nightmare is , my boss ask me to create an interactive floor ( he just saw in an exhibition ) , he ask me to create one of them instead of buying , i am an actionscript crawler and developer with some skills in java and c# programming , i just made some track motion with a simple web cam , and this idea came to my mind if i can use an infrared or thermographic camera instead of simple camera so i can get better positioning if camera place at top of floor ! Now i just came here to ask you guys is there any resource , tip , help i can know before getting into this deal !? is there any lib or api out to deal with this ?! EVEN, if there is any resource , article from another language c++ , c , .... could help i just didn't have enough time to test lot of ways If you search interactive floors , or interactive floor projection you can find some companies who provide such a thing Thanks in advance ( and sorry for my damn poor english , français could be better :D )

    Read the article

  • Hibernate criterion Projection alias not being used

    - by sbzoom
    Do Hibernate Projection aliases even work? I could swear it just doesn't. At least, it doesn't do what I would expect it to do. Here is the java: return sessionFactory.getCurrentSession().createCriteria( PersonProgramActivity.class ).setProjection( Projections.projectionList().add( Projections.alias( Projections.sum( "numberOfPoints" ), "number_of_points" ) ).add( Projections.groupProperty( "person.id" ) ) ).setFirstResult( start ).setFetchSize( size ).addOrder( Order.desc( "numberOfPoints" ) ).list(); Here is the SQL that it generates: select sum(this_.number_of_points) as y0_, this_.person_id as y1_ from PERSON_PROGRAM_ACTIVITY this_ group by this_.person_id order by this_.number_of_points desc It doesn't seem to use the alias at all. I would think setting the alias would mean that "sum(this_.number_of_points)" would be aliased as "number_of_points" and not "y0_". Is there some trick I am missing? Thanks.

    Read the article

  • Glm Vector Transformations [duplicate]

    - by Reanimation
    This question already has an answer here: Car-like Physics - Basic Maths to Simulate Steering 2 answers I have a cube rendered on the screen which represents a car (or similar). Using Projection/Model matrices and Glm I am able to move it back and fourth along the axes and rotate it left or right. I'm having trouble with the vector mathematics to make the cube move forwards no matter which direction it's current orientation is. (ie. if I would like, if it's rotated right 30degrees, when it's move forwards, it travels along the 30degree angle on a new axes). I hope I've explained that correctly. This is what I've managed to do so far in terms of using glm to move the cube: glm::vec3 vel; //velocity vector void renderMovingCube(){ glUseProgram(movingCubeShader.handle()); GLuint matrixLoc4MovingCube = glGetUniformLocation(movingCubeShader.handle(), "ProjectionMatrix"); glUniformMatrix4fv(matrixLoc4MovingCube, 1, GL_FALSE, &ProjectionMatrix[0][0]); glm::mat4 viewMatrixMovingCube; viewMatrixMovingCube = glm::lookAt(camOrigin, camLookingAt, camNormalXYZ); vel.x = cos(rotX); vel.y=sin(rotX); vel*=moveCube; //move cube ModelViewMatrix = glm::translate(viewMatrixMovingCube,globalPos*vel); //bring ground and cube to bottom of screen ModelViewMatrix = glm::translate(ModelViewMatrix, glm::vec3(0,-48,0)); ModelViewMatrix = glm::rotate(ModelViewMatrix, rotX, glm::vec3(0,1,0)); //manually turn glUniformMatrix4fv(glGetUniformLocation(movingCubeShader.handle(), "ModelViewMatrix"), 1, GL_FALSE, &ModelViewMatrix[0][0]); //pass matrix to shader movingCube.render(); //draw glUseProgram(0); } keyboard input: void keyboard() { char BACKWARD = keys['S']; char FORWARD = keys['W']; char ROT_LEFT = keys['A']; char ROT_RIGHT = keys['D']; if (FORWARD) //W - move forwards { globalPos += vel; //globalPos.z -= moveCube; BACKWARD = false; } if (BACKWARD)//S - move backwards { globalPos.z += moveCube; FORWARD = false; } if (ROT_LEFT)//A - turn left { rotX +=0.01f; ROT_LEFT = false; } if (ROT_RIGHT)//D - turn right { rotX -=0.01f; ROT_RIGHT = false; } Where am I going wrong with my vectors? I would like change the direction of the cube (which it does) but then move forwards in that direction.

    Read the article

  • Find largest rectangle containing all zero's in an N X N binary matrix

    - by Rajendra
    Given an N X N binary matrix (containing only 0's or 1's). How can we go about finding largest rectangle containing all 0's? Example: I 0 0 0 0 1 0 0 0 1 0 0 1 II->0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 <--IV 0 0 1 0 0 0 IV is a 6 X 6 binary matrix, return value in this case will be Cell 1: (2, 1) and Cell 2: (4, 4). Resulting sub-matrix can be square or rectangle. Return value can be size of the largest sub-matrix of all 0's also, for example, here 3 X 4.

    Read the article

  • obtain OpenGL camera(view) matrix from openCV findhomography

    - by user1828449
    I want to build an AR application on Android by opencv and opengl. I found GL_MODELVIEW can place camera and model in world coordinates like the following link I tried to load a simple model-view matrix by gl.glLoadMatrixf(newMat, 0); and it works so I want to draw 3d model on the top of my target image if i got the four corner points of the target image because model-view matrix is needed I want to know if I can obtain the camera view matrix by opencv's findhomography

    Read the article

  • maple 13 tridiagonal matrix help

    - by user292569
    i am trying to make a 100 x 100 tridiagonal matrix with 2's going down the diagonal and -1's surrounding the 2's. i can make a tridiagonal matrix with only 1's in the three diagonals and preform matrix addition to get what i want, but i want to know if there is a way to customize the three diagonals to what ever you want. maplehelp doesn't list anything useful.

    Read the article

  • Impact of ordering of correlated subqueries within a projection

    - by Michael Petito
    I'm noticing something a bit unexpected with how SQL Server (SQL Server 2008 in this case) treats correlated subqueries within a select statement. My assumption was that a query plan should not be affected by the mere order in which subqueries (or columns, for that matter) are written within the projection clause of the select statement. However, this does not appear to be the case. Consider the following two queries, which are identical except for the ordering of the subqueries within the CTE: --query 1: subquery for Color is second WITH vw AS ( SELECT p.[ID], (SELECT TOP(1) [FirstName] FROM [Preference] WHERE p.ID = ID AND [FirstName] IS NOT NULL ORDER BY [LastModified] DESC) [FirstName], (SELECT TOP(1) [Color] FROM [Preference] WHERE p.ID = ID AND [Color] IS NOT NULL ORDER BY [LastModified] DESC) [Color] FROM Person p ) SELECT ID, Color, FirstName FROM vw WHERE Color = 'Gray'; --query 2: subquery for Color is first WITH vw AS ( SELECT p.[ID], (SELECT TOP(1) [Color] FROM [Preference] WHERE p.ID = ID AND [Color] IS NOT NULL ORDER BY [LastModified] DESC) [Color], (SELECT TOP(1) [FirstName] FROM [Preference] WHERE p.ID = ID AND [FirstName] IS NOT NULL ORDER BY [LastModified] DESC) [FirstName] FROM Person p ) SELECT ID, Color, FirstName FROM vw WHERE Color = 'Gray'; If you look at the two query plans, you'll see that an outer join is used for each subquery and that the order of the joins is the same as the order the subqueries are written. There is a filter applied to the result of the outer join for color, to filter out rows where the color is not 'Gray'. (It's odd to me that SQL would use an outer join for the color subquery since I have a non-null constraint on the result of the color subquery, but OK.) Most of the rows are removed by the color filter. The result is that query 2 is significantly cheaper than query 1 because fewer rows are involved with the second join. All reasons for constructing such a statement aside, is this an expected behavior? Shouldn't SQL server opt to move the filter as early as possible in the query plan, regardless of the order the subqueries are written?

    Read the article

  • How to represent double values as circles in a 2d matrix in java

    - by marco
    Hello, so I want to write a matrix explorer which enables me to reorder rows and columns of a matrix. For this porpouse I used the Jtable class. Now the problem that I have is that it is very difficult to reorder a matrix by looking at double values, so I would like to print the matrix not with the double values but with circles in which the radius of the circle represents the value. So that I can tell the difference between big values and small values quicker. Anybody has any idea how I can turn this double values into filled circles with JTable or any table class for that matter?

    Read the article

  • High speed matrix manipulation in c#?

    - by Donnie
    I'm working on some image manipulation code in c# and need to do some matrix operations (specifically 2D convolution). I have the code written in matlab which uses the conv2 function ... is there a library for C# / .NET that does good high-speed matrix manipulations? I'd be fine if it requires some specific GPU and does the matrix math on-GPU if that's what it takes.

    Read the article

  • Numpy Matrix keeps giving me an Error,

    - by uberjumper
    Okay this is werid, i keep getting the error, randomly. ValueError: matrix must be 2-dimensional So i tracked it down, and cornered it to basically something like this: a_list = [[(1,100) for _ in range(32)] for _ in range(32)] numpy.matrix(a_list) Whats wrong with this? If i print a_list it is clearly a 2d matrix of tuples, however numpy does not believe so.

    Read the article

  • How can I save and read to XML the new C++ style matrix objects in OpenCV?

    - by neuviemeporte
    The old, C style cvMat matrices could be passed to the cvSave() function for easy writing to an XML file. The new C++ style cv::Mat and cv::Mat_ matrices are not accepted by this function. The OpenCV reference has a section on XML persistence, but the three classes (FileStorage, FileNode and FileNodeIterator) lack any description or example and I can't figure out how to use them from the interface. Thanks.

    Read the article

  • C++ Matrix class hierachy

    - by bpw1621
    Should a matrix software library have a root class (e.g., MatrixBase) from which more specialized (or more constrained) matrix classes (e.g., SparseMatrix, UpperTriangluarMatrix, etc.) derive? If so, should the derived classes be derived publicly/protectively/privately? If not, should they be composed with a implementation class encapsulating common functionality and be otherwise unrelated? Something else? I was having a conversation about this with a software developer colleague (I am not per se) who mentioned that it is a common programming design mistake to derive a more restricted class from a more general one (e.g., he used the example of how it was not a good idea to derive a Circle class from an Ellipse class as similar to the matrix design issue) even when it is true that a SparseMatrix "IS A" MatrixBase. The interface presented by both the base and derived classes should be the same for basic operations; for specialized operations, a derived class would have additional functionality that might not be possible to implement for an arbitrary MatrixBase object. For example, we can compute the cholesky decomposition only for a PositiveDefiniteMatrix class object; however, multiplication by a scalar should work the same way for both the base and derived classes. Also, even if the underlying data storage implementation differs the operator()(int,int) should work as expected for any type of matrix class. I have started looking at a few open-source matrix libraries and it appears like this is kind of a mixed bag (or maybe I'm looking at a mixed bag of libraries). I am planning on helping out with a refactoring of a math library where this has been a point of contention and I'd like to have opinions (that is unless there really is an objective right answer to this question) as to what design philosophy would be best and what are the pros and cons to any reasonable approach.

    Read the article

  • Implementation of a distance matrix of a binary tree that is given in the adjacency-list representation

    - by Denise Giubilei
    Given this problem I need an O(n²) implementation of this algorithm: "Let v be an arbitrary leaf in a binary tree T, and w be the only vertex connected to v. If we remove v, we are left with a smaller tree T'. The distance between v and any vertex u in T' is 1 plus the distance between w and u." This is a problem and solution of a Manber's exercise (Exercise 5.12 from U. Manber, Algorithms: A Creative Approach, Addison-Wesley (1989).). The thing is that I can't deal properly with the adjacency-list representation so that the implementation of this algorithm results in a real O(n²) complexity. Any ideas of how the implementation should be? Thanks.

    Read the article

  • building a pairwise matrix in scipy/numpy in Python from dictionaries

    - by user248237
    I have a dictionary whose keys are strings and values are numpy arrays, e.g.: data = {'a': array([1,2,3]), 'b': array([4,5,6]), 'c': array([7,8,9])} I want to compute a statistic between all pairs of values in 'data' and build an n by x matrix that stores the result. Assume that I know the order of the keys, i.e. I have a list of "labels": labels = ['a', 'b', 'c'] What's the most efficient way to compute this matrix? I can compute the statistic for all pairs like this: result = [] for elt1, elt2 in itertools.product(labels, labels): result.append(compute_statistic(data[elt1], data[elt2])) But I want result to be a n by n matrix, corresponding to "labels" by "labels". How can I record the results as this matrix? thanks.

    Read the article

  • i want to find determinant of 4x4 matrix in c#

    - by vj4u
    i want to find determinant of 4x4 matrix in c# please help urgent int ss = 4; int count = 0; int[,] matrix=new int[ss,ss]; ArrayList al = new ArrayList() {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 }; for (int i = 0; i < ss; i++) { for (int j = 0; j < ss; j++) { matrix[i, j] =Convert.ToInt32( al[count]); ++count; Response.Write(matrix[i, j] + " "); } Response.Write("<br/>"); }

    Read the article

  • Is the use of union in this matrix class completely safe?

    - by identitycrisisuk
    Unions aren't something I've used that often and after looking at a few other questions on them here it seems like there is almost always some kind of caveat where they might not work. Eg. structs possibly having unexpected padding or endian differences. Came across this in a math library I'm using though and I wondered if it is a totally safe usage. I assume that multidimensional arrays don't have any extra padding and since the type is the same for both definitions they are guaranteed to take up exactly the same amount of memory? template<typename T> class Matrix44T { ... union { T M[16]; T m[4][4]; } m; }; Are there any downsides to this setup? Would the order of definition make any difference to how this works?

    Read the article

  • R - indirectly calling a matrix using a string

    - by Boris Senderovich
    Example: There is a matrix of data called VE There is a vector of string where the first element is the string VE. I need to indirectly call the string and be able to access data. For example if I need the 6th column of matrix VE then I want to do: Vector[1][,6] Essentially I need R to start reading those string as if they are the matrix names that are already in this page. I need this syntax to be dynamic because I am putting it in a loop.

    Read the article

  • Find largest rectangle containing only zeros in an N&times;N binary matrix

    - by Rajendra
    Given an NxN binary matrix (containing only 0's or 1's), how can we go about finding largest rectangle containing all 0's? Example: I 0 0 0 0 1 0 0 0 1 0 0 1 II->0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 <--IV 0 0 1 0 0 0 IV is a 6×6 binary matrix; the return value in this case will be Cell 1: (2, 1) and Cell 2: (4, 4). The resulting sub-matrix can be square or rectangular. The return value can also be the size of the largest sub-matrix of all 0's, in this example 3 × 4.

    Read the article

  • Problem with DirectX scene-graph

    - by Alex
    I'm trying to implement a basic scene graph in DirectX using C++. I am using a left child-right sibling binary tree to do this. I'm having trouble updating each node's world transformation relative to its parent (and its parent's parent etc.). I'm struggling to get it to work recursively, though I can get it to work like this: for(int i = 0; i < NUM_OBJECTS; i++) { // Initialize to identity matrix. D3DXMatrixIdentity(&mObject[i].toWorldXForm); int k = i; while( k != -1 ) { mObject[i].toWorldXForm *= mObject[k].toParentXForm; k = mObject[k].parent; } } toWorldXForm is the object's world transform and toParentXForm is the object's transform relative to the parent. I want to do this using a method within my object class (the code above is in my main class). This is what I've tried but it doesn't work (only works with nodes 1 generation away from the root) if (this->sibling != NULL) this->sibling->update(toParentXForm); D3DXMatrixIdentity(&toWorldXForm); this->toWorldXForm *= this->toParentXForm; this->toWorldXForm *= toParentXForm; toParentXForm *= this->toParentXForm; if (this->child != NULL) this->child->update(toParentXForm); Sorry if I've not been clear, please tell me if there's anything else you need to know. I've no doubt it's merely a silly mistake on my part, hopefully an outside view will be able to spot the problem.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 13 14 15 16 17 18 19 20 21 22 23 24  | Next Page >