Search Results

Search found 812 results on 33 pages for 'computational geometry'.

Page 18/33 | < Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >

  • Best Graphics card (Setup) for three, high-res monitors attached to desktop

    - by nomrasco
    I have been looking around a little bit, but most of the discussions are about problems with already existing systems (particular graphics card and setup etc.). I would like to ask what would be the best option for me if I want to build powerful desktop with triple monitor setup. I have one Dell UltraSharp U2713HM (27 inches, 2560x1440) and I was thinking about getting two more. Would it be possible to have those three working with ubuntu (kubuntu) on any graphics card out there today? What is the best option if it comes to choosing particular model? Should I use proprietary drivers or some open sourced ones? I am not a gamer. I mostly develop on my machines and running some computational tasks, but I would rather like to spend some more money and have setup where I don't see any lags :) thank You very much in advance! Darek

    Read the article

  • MediaElement not showing in custom 3D class

    - by user3271180
    I'm trying to display a videostream in a Viewport3d. When I add the MediaElement via xaml, the video plays without a problem; even when I add the video as ModelVisual3D in the code-behind, the video works. When I abstract the video into a class, however, the video stops appearing. This happens with both web and local video files. I tried compiling with both x86 and 64 bit. Any way to fix this behaviour? Why is this happening? I have the following viewport: <Viewport3D> <!-- Camera --> <Viewport3D.Camera> <PerspectiveCamera Position="0,0,100" LookDirection="0,0,-1" UpDirection="0,1,0" /> </Viewport3D.Camera> <!-- Light --> <ModelVisual3D> <ModelVisual3D.Content> <AmbientLight Color="White" /> </ModelVisual3D.Content> </ModelVisual3D> <!-- this doesn't work --> <mediaElementTest:VideoControl /> <!-- but this does? --> <!--<ModelVisual3D> <ModelVisual3D.Content> <GeometryModel3D> <GeometryModel3D.Geometry> <MeshGeometry3D Positions="-100,-100,0 100,-100,0 100,100,0 -100,100,0" TextureCoordinates="0,1 1,1 1,0 0,0" TriangleIndices="0 1 2 0 2 3" /> </GeometryModel3D.Geometry> <GeometryModel3D.Material> <DiffuseMaterial> <DiffuseMaterial.Brush> <VisualBrush> <VisualBrush.Visual> <MediaElement Source="http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4" /> </VisualBrush.Visual> </VisualBrush> </DiffuseMaterial.Brush> </DiffuseMaterial> </GeometryModel3D.Material> </GeometryModel3D> </ModelVisual3D.Content> </ModelVisual3D>--> </Viewport3D> VideoControl.xaml <UIElement3D x:Class="MediaElementTest.VideoControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"/> VideoControl.xaml.cs public partial class VideoControl { public VideoControl() { InitializeComponent(); Visual3DModel = CreateModel(); } private GeometryModel3D CreateModel() { return new GeometryModel3D { Geometry = new MeshGeometry3D { Positions = new Point3DCollection { new Point3D(-100, -100, 0), new Point3D(100, -100, 0), new Point3D(100, 100, 0), new Point3D(-100, 100, 0) }, TextureCoordinates = new PointCollection { new Point(0, 1), new Point(1, 1), new Point(1, 0), new Point(0, 0) }, TriangleIndices = new Int32Collection { 0, 1, 2, 0, 2, 3 } }, Material = new DiffuseMaterial(new VisualBrush(new MediaElement { Source = new Uri("http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4", UriKind.RelativeOrAbsolute) })) }; } }

    Read the article

  • SQL SERVER – What is Spatial Database? – Developing with SQL Server Spatial and Deep Dive into Spati

    - by pinaldave
    What is Spatial Database? A spatial database is a database that is optimized to store and query data related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types. (Source: Wikipedia) Today I will be talking about the same subject at Microsoft TechEd India. If you want to learn about how to spatial aspect of data and how to integrate them with SQL Server this is the perfect session for you. Spatial is very special concept of SQL Server and I really like how it is implemented in SQL Server. In general Performance Tuning and Query Optimization is something I always have enjoyed in my professional life. Index are my best friends and many time, by implementing and many time by removing I have improved the performance of the system. In this session, I will be talking about Index along with Spatial Data. As Spatial Database is very interesting concept, I will cover super short but very interesting 10 quick slides about this subject. I will make sure in very first 20 mins, you will understand following topics Introduction to Spatial Database One line definition Understanding Spatial Indexing Index Internals Query/Performance Tuning Query Hinting/Cost Analysis Spatial Index Catalog Views Performance Troubleshooting Finding Optimal Index using Spatial Index SP Common Errors Index Maintenance This slides decks will be followed by around 30 mins demo which will have story of geometry, geography, index internals and performance tuning. If you are interested in learning how GIS works and how SQL Server out of the box supports this wonderful tools, you will really like how the story is told. I am sure all people who attend the event will know how the Bangalore is positioned on the map of India. I will take example of Bangalore and Hyderabad and demonstrate how index can improve the performance. Well there are lots of story to tell in the session, and I will be opening this session with the beautiful script of Botticelli’s Birth of Venus created by Michael J. Swart. I will also demonstrate few real life scenario where I will be talking about Spatial Database and its usage. Do not miss this session. At the end of session there will be book awarded to best participant. My session details: Session 3: Developing with SQL Server Spatial and Deep Dive into Spatial Indexing Date: April 14, 2010 Time: 5:00pm-6:00pm Microsoft SQL Server 2008 delivers new spatial data types that enable you to consume, use, and extend location-based data through spatial-enabled applications. Attend this session to learn how to use spatial functionality in next version of SQL Server to build and optimize spatial queries. This session outlines the new geography data type to store geodetic spatial data and perform operations on it, use the new geometry data type to store planar spatial data and perform operations on it, take advantage of new spatial indexes for high performance queries, use the new spatial results tab to quickly and easily view spatial query results directly from within Management Studio, extend spatial data capabilities by building or integrating location-enabled applications through support for spatial standards and specifications and much more. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology Tagged: Spatial Database

    Read the article

  • Problems with texture orientation in space

    - by frankie
    I am currently drawing texture in 3D space and have some problems with it's orientation. I'd like me textures always to be oriented with front face to user. My desirable result looks like Note, that text size stay without changes when we rotating world and stay oriented with front face to user. Now I can draw text in 3D space, but it is not oriented with front but rotating with world. Such results I got with following shaders: Vertex Shader uniform vec3 Position; void main() { gl_Position = vec4(Position, 1.0); } Geometry Shader layout(points) in; layout(triangle_strip, max_vertices = 4) out; out vec2 fsTextureCoordinates; uniform mat4 projectionMatrix; uniform mat4 modelViewMatrix; uniform sampler2D og_texture0; uniform float og_highResolutionSnapScale; uniform vec2 u_originScale; void main() { vec2 halfSize = vec2(textureSize(og_texture0, 0)) * 0.5 * og_highResolutionSnapScale; vec4 center = gl_in[0].gl_Position; center.xy += (u_originScale * halfSize); vec4 v0 = vec4(center.xy - halfSize, center.z, 1.0); vec4 v1 = vec4(center.xy + vec2(halfSize.x, -halfSize.y), center.z, 1.0); vec4 v2 = vec4(center.xy + vec2(-halfSize.x, halfSize.y), center.z, 1.0); vec4 v3 = vec4(center.xy + halfSize, center.z, 1.0); gl_Position = projectionMatrix * modelViewMatrix * v0; fsTextureCoordinates = vec2(0.0, 0.0); EmitVertex(); gl_Position = projectionMatrix * modelViewMatrix * v1; fsTextureCoordinates = vec2(1.0, 0.0); EmitVertex(); gl_Position = projectionMatrix * modelViewMatrix * v2; fsTextureCoordinates = vec2(0.0, 1.0); EmitVertex(); gl_Position = projectionMatrix * modelViewMatrix * v3; fsTextureCoordinates = vec2(1.0, 1.0); EmitVertex(); } Fragment Shader in vec2 fsTextureCoordinates; out vec4 fragmentColor; uniform sampler2D og_texture0; uniform vec3 u_color; void main() { vec4 color = texture(og_texture0, fsTextureCoordinates); if (color.a == 0.0) { discard; } fragmentColor = vec4(color.rgb * u_color.rgb, color.a); } Any ideas how to get my desirable result? EDIT 1: I make edit in my geometry shader and got part of lable drawn on screen at corner. But it is not rotating. .......... vec4 centerProjected = projectionMatrix * modelViewMatrix * center; centerProjected /= centerProjected.w; vec4 v0 = vec4(centerProjected.xy - halfSize, 0.0, 1.0); vec4 v1 = vec4(centerProjected.xy + vec2(halfSize.x, -halfSize.y), 0.0, 1.0); vec4 v2 = vec4(centerProjected.xy + vec2(-halfSize.x, halfSize.y), 0.0, 1.0); vec4 v3 = vec4(centerProjected.xy + halfSize, 0.0, 1.0); gl_Position = og_viewportOrthographicMatrix * v0; ..........

    Read the article

  • OpenGL Fast-Object Instancing Error

    - by HJ Media Studios
    I have some code that loops through a set of objects and renders instances of those objects. The list of objects that needs to be rendered is stored as a std::map, where an object of class MeshResource contains the vertices and indices with the actual data, and an object of classMeshRenderer defines the point in space the mesh is to be rendered at. My rendering code is as follows: glDisable(GL_BLEND); glEnable(GL_CULL_FACE); glDepthMask(GL_TRUE); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_DEPTH_TEST); for (std::map<MeshResource*, std::vector<MeshRenderer*> >::iterator it = renderables.begin(); it != renderables.end(); it++) { it->first->setupBeforeRendering(); cout << "<"; for (unsigned long i =0; i < it->second.size(); i++) { //Pass in an identity matrix to the vertex shader- used here only for debugging purposes; the real code correctly inputs any matrix. uniformizeModelMatrix(Matrix4::IDENTITY); /** * StartHere fix rendering problem. * Ruled out: * Vertex buffers correctly. * Index buffers correctly. * Matrices correct? */ it->first->render(); } it->first->cleanupAfterRendering(); } geometryPassShader->disable(); glDepthMask(GL_FALSE); glDisable(GL_CULL_FACE); glDisable(GL_DEPTH_TEST); The function in MeshResource that handles setting up the uniforms is as follows: void MeshResource::setupBeforeRendering() { glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glEnableVertexAttribArray(2); glEnableVertexAttribArray(3); glEnableVertexAttribArray(4); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, iboID); glBindBuffer(GL_ARRAY_BUFFER, vboID); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0); // Vertex position glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 12); // Vertex normal glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 24); // UV layer 0 glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 32); // Vertex color glVertexAttribPointer(4, 1, GL_UNSIGNED_SHORT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 44); //Material index } The code that renders the object is this: void MeshResource::render() { glDrawElements(GL_TRIANGLES, geometry->numIndices, GL_UNSIGNED_SHORT, 0); } And the code that cleans up is this: void MeshResource::cleanupAfterRendering() { glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); glDisableVertexAttribArray(2); glDisableVertexAttribArray(3); glDisableVertexAttribArray(4); } The end result of this is that I get a black screen, although the end of my rendering pipeline after the rendering code (essentially just drawing axes and lines on the screen) works properly, so I'm fairly sure it's not an issue with the passing of uniforms. If, however, I change the code slightly so that the rendering code calls the setup immediately before rendering, like so: void MeshResource::render() { setupBeforeRendering(); glDrawElements(GL_TRIANGLES, geometry->numIndices, GL_UNSIGNED_SHORT, 0); } The program works as desired. I don't want to have to do this, though, as my aim is to set up vertex, material, etc. data once per object type and then render each instance updating only the transformation information. The uniformizeModelMatrix works as follows: void RenderManager::uniformizeModelMatrix(Matrix4 matrix) { glBindBuffer(GL_UNIFORM_BUFFER, globalMatrixUBOID); glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(Matrix4), matrix.ptr()); glBindBuffer(GL_UNIFORM_BUFFER, 0); }

    Read the article

  • Python Tkinter Tix: How to use ScrolledWindow with grid in Tix NoteBook

    - by Sano98
    Hi guys, I'm adding several widgets to a Frame which is located in a tix.NoteBook. When there are too much widgets to fit in the window, I want to use a scrollbar, so I put tix.ScrolledWindow inside that Frame and add my widgets to this ScrolledWindow instead. The problem is that when using the grid() geometry manager, the scrollbar appears, but it is not working (The drag bar occupies the whole scroll bar). from Tkinter import * import Tix class Window: def __init__(self, root): self.labelList = [] self.notebook = Tix.NoteBook(root, ipadx=3, ipady=3) self.notebook.add('sheet_1', label="Sheet 1", underline=0) self.notebook.add('sheet_2', label="Sheet 2", underline=0) self.notebook.add('sheet_3', label="Sheet 3", underline=0) self.notebook.pack() #self.notebook.grid(row=0, column=0) tab1=self.notebook.sheet_1 tab2=self.notebook.sheet_2 tab3=self.notebook.sheet_3 self.myMainContainer = Frame(tab1) self.myMainContainer.pack() #self.myMainContainer.grid(row=0, column=0) scrwin = Tix.ScrolledWindow(self.myMainContainer, scrollbar='y') scrwin.pack() #scrwin.grid(row=0, column=0) self.win = scrwin.window for i in range (100): self.labelList.append((Label(self.win))) self.labelList[-1].config(text= "Bla", relief = SUNKEN) self.labelList[-1].grid(row=i, column=0, sticky=W+E) root = Tix.Tk() myWindow = Window(root) root.mainloop() Whenever I change at least one of the geometry managers from pack() to grid(), the problem occurs. (Actually, I'd prefer using grid() for all containers.) When I don't use the NoteBook widget, the problem does not occur either. The other examples here all seem to rely on pack(). Any ideas? Many thanks, Sano

    Read the article

  • What is wrong with Paperclip+ImageMagick on Heroku?

    - by Yuri
    UPD class User < ActiveRecord::Base Paperclip.options[:swallow_stderr] = false has_attached_file :photo, :styles => { :square => "100%", :large => "100%" }, :convert_options => { :square => "-auto-orient -geometry 70X70#", :large => "-auto-orient -geometry X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' validates_attachment_size :photo, :less_than => 5.megabyte end Works great on local machine, but gives me an error on Heroku: There was an error processing the thumbnail for stream.20143 The thing is I want to auto-orient photos before resizing, so they resized properly. The only working variant now(thanks to jonnii) is resizing without auto-orient: ... as_attached_file :photo, :styles => { :square => "70X70#", :large => "X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' ... How to pass additional convert options to paperclip on Heroku?

    Read the article

  • File Translator to Export Animated 3D Character from Autodesk Maya as Quake MD2

    - by Andy R
    I'm wondering if anyone knows of a way to export geometry/textures for a rigged, animated character as Quake MD2? I’m developing an app for mobile devices, and I’ve found that MD2 works great for lightweight OpenGL rendering. I have several animated characters, and I’d like to export them as MD2 from Maya. Here are some of the things I have tried: Exporting FBX to 3D Studio Max and using the QTip plugin -- this works, but only if I convert my animation to point cache (pc2) and bring that into Max. When I do that, QTip plugin doesn’t honor the point cache node, and all I get is the model, no animation Exporting OBJ Sequence to Blender, exporting MD2 from there -- I can’t seem to get blender to compile the imported obj sequence into a single animated object Exporting FBX to Milkshape -- the maya rig gets corrupted in the process Bake point cache for animation, export to FBX, import to Milkshape -- again, Milkshape doesn’t honor the geometry cache, so all that appears is a static character. I’m currently writing a plugin for Maya using the blender MD2 export script as reference (but re-writing using the C++ Maya API), but I’m just wondering if anyone has done this before or has any suggestions of how to do this. Also, if anyone has other suggestions for the best format to render a single animated character on an OpenGL ES (Android or iPhone) device, I would be very grateful! I’m open to trying anything to get these animations rendering on device Thanks!

    Read the article

  • In WPF 3D, why can't a perspective camera's LookDirection be straight down?

    - by DanM
    I'm attempting to position my perspective camera 30 units above the origin and pointing straight down. If I set the LookDirection of the camera to "0,0,-1", however, everything disappears. I have to make it "0.01,0.01,-1" for it to work. Why? <Window x:Class="ThreeDeeTester.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300"> <Grid> <Viewport3D> <Viewport3D.Camera> <PerspectiveCamera Position="0,0,30" LookDirection="0.01,0.01,-1" UpDirection="0,0,1" /> <!-- LookDirection="0,0,-1" doesn't work...why? --> </Viewport3D.Camera> <ModelVisual3D> <ModelVisual3D.Content> <Model3DGroup> <DirectionalLight Color="White" Direction="1,-1,-1" /> <GeometryModel3D> <GeometryModel3D.Geometry> <MeshGeometry3D Positions="0,0,10 -5,-5,0 -5,5,0 5,5,0 5,-5,0" TriangleIndices="2 1 0 2 0 3 4 3 0 1 4 0" /> </GeometryModel3D.Geometry> <GeometryModel3D.Material> <DiffuseMaterial Brush="Red" /> </GeometryModel3D.Material> </GeometryModel3D> </Model3DGroup> </ModelVisual3D.Content> </ModelVisual3D> </Viewport3D> </Grid> </Window>

    Read the article

  • How to pass additional convert options to paperclip on Heroku?

    - by Yuri
    UPD class User < ActiveRecord::Base Paperclip.options[:swallow_stderr] = false has_attached_file :photo, :styles => { :square => "100%", :large => "100%" }, :convert_options => { :square => "-auto-orient -geometry 70X70#", :large => "-auto-orient -geometry X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' validates_attachment_size :photo, :less_than => 5.megabyte end Works great on local machine, but gives me an error on Heroku: There was an error processing the thumbnail for stream.20143 The thing is I want to auto-orient photos before resizing, so they resized properly. The only working variant now(thanks to jonnii) is resizing without auto-orient: ... as_attached_file :photo, :styles => { :square => "70X70#", :large => "X300" }, :storage => :s3, :s3_credentials => "#{RAILS_ROOT}/config/s3.yml", :path => ":attachment/:id/:style.:extension", :bucket => 'mybucket' ... How to pass additional convert options to paperclip on Heroku?

    Read the article

  • How to include multiple tables programmaticaly into a Sweave document using R

    - by PaulHurleyuk
    Hello, I want to have a sweave document that will include a variable number of tables in. I thought the example below would work, but it doesn't. I want to loop over the list foo and print each element as it's own table. % \documentclass[a4paper]{article} \usepackage[OT1]{fontenc} \usepackage{longtable} \usepackage{geometry} \usepackage{Sweave} \geometry{left=1.25in, right=1.25in, top=1in, bottom=1in} \listfiles \begin{document} <<label=start, echo=FALSE, include=FALSE>>= startt<-proc.time()[3] library(RODBC) library(psych) library(xtable) library(plyr) library(ggplot2) options(width=80) #Produce some example data, here I'm creating some dummy dataframes and putting them in a list foo<-list() foo[[1]]<-data.frame(GRP=c(rep("AA",10), rep("Aa",10), rep("aa",10)), X1=rnorm(30), X2=rnorm(30,5,2)) foo[[2]]<-data.frame(GRP=c(rep("BB",10), rep("bB",10), rep("BB",10)), X1=rnorm(30), X2=rnorm(30,5,2)) foo[[3]]<-data.frame(GRP=c(rep("CC",12), rep("cc",18)), X1=rnorm(30), X2=rnorm(30,5,2)) foo[[4]]<-data.frame(GRP=c(rep("DD",10), rep("Dd",10), rep("dd",10)), X1=rnorm(30), X2=rnorm(30,5,2)) @ \title{Docuemnt to test putting a variable number of tables into a sweave Document} \author{"Paul Hurley"} \maketitle \section{Text} This document was created on \today, with \Sexpr{print(version$version.string)} running on a \Sexpr{print(version$platform)} platform. It took approx \input{time} sec to process. <<label=test, echo=FALSE, results=tex>>= cat("Foo") @ that was a test, so is this <<label=table1test, echo=FALSE, results=tex>>= print(xtable(foo[[1]])) @ \newpage \subsection{Tables} <<label=Tables, echo=FALSE, results=tex>>= for(i in seq(foo)){ cat("\n") cat(paste("Table_",i,sep="")) cat("\n") print(xtable(foo[[i]])) cat("\n") } #cat("<<label=endofTables>>= ") @ <<label=bye, include=FALSE, echo=FALSE>>= endt<-proc.time()[3] elapsedtime<-as.numeric(endt-startt) @ <<label=elapsed, include=FALSE, echo=FALSE>>= fileConn<-file("time.tex", "wt") writeLines(as.character(elapsedtime), fileConn) close(fileConn) @ \end{document} Here, the table1test chunk works as expected, and produced a table based on the dataframe in foo[[1]], however the loop only produces Table(underscore)1.... Any ideas what I'm doing wrong ?

    Read the article

  • Overlaying 2D paths on UIImage without scaling artifacts

    - by tat0
    I need to draw a path along the shape of an image in a way that it is always matching its position on the image independent of the image scale. Think of this like the hybrid view of Google Maps where streets names and roads are superimposed on top of the aerial pictures. Furthermore, this path will be drawn by the user's finger movements and I need to be able to retrieve the path keypoints on the image pixel coordinates. The user zooms-in in order to more precisely set the paths location. I manage to somehow make it work using this approach: -Create a custom UIView called CanvasView that handles touches interaction and delivers scaling, rotation, translation values to either the UIImageView or PathsView (see bellow) depending on a flag: deliverToImageOrPaths. -Create a UIImageView holding the base image. This is set as a children of CanvasView -Create a custom UIView called PathsView that keeps track of the 2D paths geometry and draws itself with a custom drawRect. This is set as children of the UIImageView. So hierarchy: CanvasView - UIImageView -PathsView In this way when deliverToImageOrPaths is YES, finger gestures transforms both the UIImageView and its child PathsView. When deliverToImageOrPaths is NO the gestures affect only the PathsView altering its geometry. So far so good. QUESTION: The problem I have is that when scaling the base UIImageView (via its .transform property) the PathsView is scaled with aliasing artifacts. drawRect is still being called on the PathsView but I guess it's performing the drawing using the original buffer size and then interpolating. How can I solve this issue? Are there better ways to implement these features? PS: I tried changing the PathsView layer class to CATiledLayer with levelsOfDetailBias 4 and levelsOfDetail 4. It solves the aliasing problem to some extent but it's unacceptable slow to render.

    Read the article

  • how to tile 3D mesh with image brush in XAML

    - by MC9000
    I have a 2D square in a ViewPort3D that I want to do a tiling of an image (like a checkerboard or flooring with "tiles" effect). I've created an image brush (the image is 50x50 pixels, the surface 250x550 pixels) and a viewport (trying to follow MS's site - though their example is for 2D), but only 1 of the colors in the "tile" image shows up and no tiling is seen. I can't find a single example on the Internet and MS's site has no info (that I can find) on 3D XAML anywhere, so I'm stumped as how to actually do this. <Viewport3D> <Viewport3D.Camera> <PerspectiveCamera Position="125,790,120" LookDirection="0,-.7,-0.25" UpDirection="0,0,1" /> </Viewport3D.Camera> <ModelVisual3D> <ModelVisual3D.Content> <Model3DGroup> <AmbientLight Color="white" /> <GeometryModel3D> <GeometryModel3D.Geometry> <MeshGeometry3D Positions="0,0,0 250,0,0 250,550,0 0,550,0 " TriangleIndices="0 1 3 1 2 3 "/> </GeometryModel3D.Geometry> <GeometryModel3D.Material> <DiffuseMaterial> <DiffuseMaterial.Brush> <ImageBrush ViewportUnits="Absolute" TileMode="Tile" ImageSource="testsquare.gif" Viewport="0,0,50,50" Stretch="None" ViewboxUnits="Absolute" /> </DiffuseMaterial.Brush> </DiffuseMaterial> </GeometryModel3D.Material> </GeometryModel3D> </Model3DGroup> </ModelVisual3D.Content> </ModelVisual3D> </Viewport3D>

    Read the article

  • How can I extend this SQL query to find the k nearest neighbors?

    - by Smigs
    I have a database full of two-dimensional data - points on a map. Each record has a field of the geometry type. What I need to be able to do is pass a point to a stored procedure which returns the k nearest points (k would also be passed to the sproc, but that's easy). I've found a query at http://blogs.msdn.com/isaac/archive/2008/10/23/nearest-neighbors.aspx which gets the single nearest neighbour, but I can't figure how to extend it to find the k nearest neighbours. This is the current query - T is the table, g is the geometry field, @x is the point to search around, Numbers is a table with integers 1 to n: DECLARE @start FLOAT = 1000; WITH NearestPoints AS ( SELECT TOP(1) WITH TIES *, T.g.STDistance(@x) AS dist FROM Numbers JOIN T WITH(INDEX(spatial_index)) ON T.g.STDistance(@x) < @start*POWER(2,Numbers.n) ORDER BY n ) SELECT TOP(1) * FROM NearestPoints ORDER BY n, dist The inner query selects the nearest non-empty region and the outer query then selects the top result from that region; the outer query can easily be changed to (e.g.) SELECT TOP(20), but if the nearest region only contains one result, you're stuck with that. I figure I probably need to recursively search for the first region containing k records, but without using a table variable (which would cause maintenance problems as you have to create the table structure and it's liable to change - there're lots of fields), I can't see how.

    Read the article

  • Selecting a good SQL Server 2008 spatial index with large polygons

    - by andynormancx
    I'm having some fun trying to pick a decent SQL Server 2008 spatial index setup for a data set I am dealing with. The dataset is polygons, representing contours over the whole globe. There are 106,000 rows in the table, the polygons are stored in a geometry field. The issue I have is that many of the polygons cover a large portion of the globe. This seems to make it very hard to get a spatial index that will eliminate many rows in the primary filter. For example, look at the following query: SELECT "ID","CODE","geom".STAsBinary() as "geom" FROM "dbo"."ContA" WHERE "geom".Filter( geometry::STGeomFromText('POLYGON ((-142.03193662573682 59.53396984952896, -142.03193662573682 59.88928136451884, -141.32743833481925 59.88928136451884, -141.32743833481925 59.53396984952896, -142.03193662573682 59.53396984952896))', 4326) ) = 1 This is querying an area which intersects with only two of the polygons in the table. No matter what combination of spatial index settings I chose, that Filter() always returns around 60,000 rows. Replacing Filter() with STIntersects() of course returns just the two polygons I want, but of course takes much longer (Filter() is 6 seconds, STIntersects() is 12 seconds). Can anyone give me any hints on whether there is a spatial index setup that is likely to improve on 60,000 rows or is my dataset just not a good match for SQL Server's spatial indexing ?

    Read the article

  • Perl+Image::Magick usage: how to assemble several areas in one image into a new image?

    - by Jin
    Hi Everybody, I'm new to ImageMagick and haven't figured out how to assemble several areas into a new image. E.g., I know the "geometry" of words "hello" and "world" respectively in an image, what I need to do is to retrieve the word images and put then into one line image while keep their relative positions. Question1: Suppose I use the perl API, how should I use Composite() or other correct methods to do this? my $geom = sprintf('%dx%x+%d+%d', $word->{width}, $word->{height}, $offsetx, $offsety); $x = $lineimg->Composite($wordimg, $geom); warn "$x" if "$x"; Suppose $lineimg's size is big enough to hold all word images and the geometry has been computed. This code gives out a complain by ImageMagick: Exception 410: composite image required `Image::Magick' @ Magick.xs/XS_Image__Magick_Mogrify/7790 ... Question2: currently I only know how to crop a word image out of the original one and then Clone() method to restore the original image. Is there a way to copy instead of crop a specific area from a image? This way can save the time to copy back and forth the whole image several times. Does anybody know how to write this kind of processing? I appreciate all your help and suggestions! -Jin

    Read the article

  • Could a truly random number be generated using pings to psuedo-randomly selected IP addresses?

    - by _ande_turner_
    The question posed came about during a 2nd Year Comp Science lecture while discussing the impossibility of generating numbers in a deterministic computational device. This was the only suggestion which didn't depend on non-commodity-class hardware. Subsequently nobody would put their reputation on the line to argue definitively for or against it. Anyone care to make a stand for or against. If so, how about a mention as to a possible implementation?

    Read the article

  • Suggested (simple) approach for drawing large numbers of visual elements in WPF?

    - by Ender
    I'm writing an interface that features a large (~50000px width) "canvas"-type area that is used to display a lot of data in a fairly novel way. This involves lots of lines, rectangles, and text. The user can scroll around to explore the entire canvas. At the moment I'm just using a standard Canvas panel with various Shapes placed on it. This is nice and easy to do: construct a shape, assign some coordinates, and attach it to the Canvas. Unfortunately, it's pretty slow (to construct the children, not to do the actual rendering). I've looked into some alternatives, it's a bit intimidating. I don't need anything fancy - just the ability to efficiently construct and place objects in a coordinate plane. If all I get are lines, colored rectangles, and text, I'll be happy. Do I need Geometry instances inside of Geometry Groups inside of GeometryDrawings inside of some Panel container? Note: I'd like to include text and graphics (i.e. colored rectangles) in the same space, if possible.

    Read the article

  • Is it possible to include a Sexpr before the expression has been evaluated in Sweave / R ?

    - by PaulHurleyuk
    Hello, I'm writing a Sweave document, and I want to include a small section that details the R and package versions, platofrms and how long ti took to evalute the doucment, however, I want to put this in the middle of the document ! I was using a \Sexpr{elapsed} to do this (which didn't work), but thought if I put the code printing elapsed in a chunk that evaluates at the end, I could then include the chunk half way through, which also fails. My document looks something like this % \documentclass[a4paper]{article} \usepackage[OT1]{fontenc} \usepackage{longtable} \usepackage{geometry} \usepackage{Sweave} \geometry{left=1.25in, right=1.25in, top=1in, bottom=1in} \begin{document} <<label=start, echo=FALSE, include=FALSE>>= startt<-proc.time()[3] @ Text and Sweave Code in here % This document was created on \today, with \Sexpr{print(version$version.string)} running on a \Sexpr{print(version$platform)} platform. It took approx sec to process. <<>>= <<elapsed>> @ More text and Sweave code in here <<label=bye, include=FALSE, echo=FALSE>>= odbcCloseAll() endt<-proc.time()[3] elapsedtime<-as.numeric(endt-startt) @ <<label=elapsed, include=FALSE, echo=FALSE>>= print(elapsedtime) @ \end{document} But this doesn't seem to work (amazingly !) Does anyone know how I could do this ? Thanks Paul.

    Read the article

  • What is the motivation behind c++0x lambda expressions?

    - by LoudNPossiblyRight
    I am trying to find out if there is an actual computational benefit to using lambda expressions in c++, namely "this code compiles/runs faster/slower because we use lambda expressions" OR is it just a neat development perk open for abuse by poor coders trying to look cool? Thanks. PS. I understand this question may seem subjective but i would much appreciate the opinion of the community on this matter.

    Read the article

  • How to use MySQL geospatial extensions with spherical geometries

    - by Joshua
    Hi Everyone, I would like to store thousands of latitude/longitude points in a MySQL db. I was successful at setting up the tables and adding the data using the geospatial extensions where the column 'coord' is a Point(lat, lng). Problem: I want to quickly find the 'N' closest entries to latitude 'X' degrees and longitude 'Y' degrees. Since the Distance() function has not yet been implemented, I used GLength() function to calculate the distance between (X,Y) and each of the entries, sorting by ascending distance, and limiting to 'N' results. The problem is that this is not calculating shortest distance with spherical geometry. Which means if Y = 179.9 degrees, the list of closest entries will only include longitudes of starting at 179.9 and decreasing even though closer entries exist with longitudes increasing from -179.9. How does one typically handle the discontinuity in longitude when working with spherical geometries in databases? There has to be an easy solution to this, but I must just be searching for the wrong thing because I have not found anything helpful. Should I just forget the GLength() function and create my own function for calculating angular separation? If I do this, will it still be fast and take advantage of the geospatial extensions? Thanks! josh UPDATE: This is exactly what I am describing above. However, it is only for SQL Server. Apparently SQL Server has a Geometry and Geography datatypes. The geography does exactly what I need. Is there something similar in MySQL?

    Read the article

  • Converting Source ASCII Files to JPEGs

    - by CommonsWare
    I publish technical books, in print, PDF, and Kindle/MOBI, with EPUB on the way. The Kindle does not support monospace fonts, which are kinda useful for source code listings. The only way to do monospace fonts is to convert the text (Java source, HTML, XML, etc.) into JPEG images. More specifically, due to pagination issues, a given input ASCII file needs to be split into slices of ~6 lines each, with each slice turned into a JPEG, so listings can span a screen. This is a royal pain. My current mechanism to do that involves: Running expand to set a consistent 2-space tab size, which pipes to... a2ps, which pipes to... A small Perl snippet to add a "%%LanguageLevel: 3\n" line, which pipes to... ImageMagick's convert, to take the (E)PS and make a JPEG out it, with an appropriate background, cropped to 575x148+5+28, etc. That used to work 100% of the time. It now works 95% of the time. The rest of the time, I get convert: geometry does not contain image errors, which I cannot seem to get rid of, in part because I don't understand what the problem is. Before this process, I used to use a pretty-print engine (source-highlight) to get HTML out of the source code...but then the only thing I could find to convert the HTML into JPEGs was to automate screen-grabs from an embedded Gecko engine. Reliability stank, which is why I switched to my current mechanism. So, if you were you, and you needed to turn source listings into JPEG images, in an automated fashion, how would you do it? Bonus points if it offers some sort of pretty-print process (e.g., bolded keywords)! Or, if you know what typically causes convert: geometry does not contain image, that might help. My current process is ugly, but if I could get it back to 100% reliability, that'd be just fine for now. Thanks in advance!

    Read the article

< Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >