Search Results

Search found 2892 results on 116 pages for '3d reconstruction'.

Page 44/116 | < Previous Page | 40 41 42 43 44 45 46 47 48 49 50 51  | Next Page >

  • Learning OpenGL ES 1.x

    - by Kristopher Johnson
    What is the quickest way to come up to speed on OpenGL ES 1.x? Let's assume I know nothing about OpenGL (which is not entirely true, but it's been a while since I last used OpenGL). I am most interested in learning this for iPhone-related development, but I'm interested in learning how it works on other platforms as well. I've found the book OpenGL ES 2.0 Programming Guide, but I am concerned that it might not be the best approach because it focuses on 2.0 rather than 1.x. My understanding is that 2.0 is not backwards-compatible with 1.x, so I may miss out on some important concepts. Note: For answers about learning general OpenGL, see http://stackoverflow.com/questions/62540/learning-opengl Some resources I've found: http://khronos.org/opengles/1_X/ http://www.imgtec.com/powervr/insider/sdk/KhronosOpenGLES1xMBX.asp OpenGL Distilled by Paul Martz (a good refresher on OpenGL basics)

    Read the article

  • What is the most mature library to render equirectangular images in Flash?

    - by Dave Viner
    I have a series of equirectangular images. I'd like to display them in a custom Flash player so that the user could see the spherical nature of the images, and "look up", "look down", "look left/right" (or pan, zoom, etc). (Note that I have a long series of images, so the library must allow for dynamic loading of the images themselves, rather than having the images "baked" into the SWF player.) What is the best library to manage the display of the equirectangular images in Flash? By "best", I mean the most mature, most reliable, most robust, and fastest performing. For reference, an example of an equirectangular image can be found at http://archive.bigben.id.au/tutorials/360/background/projections.html.

    Read the article

  • Interpolating height for a point inside a grid based on a discrete height function.

    - by fastrack20
    Hi, I have been wracking my brain to come up with a solution to this problem. I have a lookup table that returns height values for various points (x,z) on the grid. For instance I can calculate the height at A, B, C and D in Figure 1. However, I am looking for a way to interpolate the height at P (which has a known (x,z)). The lookup table only has values at the grid intervals, and P lies between these intervals. I am trying to calculate values s and t such that: A'(s) = A + s(C-A) B'(t) = B + t(P-B) I would then use the these two equations to find the intersection point of B'(t) with A'(s) to find a point X on the line A-C. With this I can calculate the height at this point X and with that the height at point P. My issue lies in calculating the values for s and t. Any help would be greatly appreciated.

    Read the article

  • OpenGL - lighting of vertices outside clip range

    - by hmp
    I have a problem with lighting in my OpenGL application. When one of the vertices of a drawn polygon goes outside the front clip plane (or has z<0, I'm not sure which), the polygon stops being lighted properly. This however happens on only one machine I tested, with Intel GMA950 card. On nVidia and ATI cards everything looks fine. I guess I am breaking some OpenGL rule here? How should I deal with it? I'd try dividing the scene into smaller polygons, but I'm not sure if it guarantees the case is eliminated (all polygons stepping outside the clipping range are offscreen).

    Read the article

  • Optimum ordering for packed vertex arrays on iPhone

    - by Pestilence
    Is there an optimum packing format for vertex arrays on the iPhone hardware? My textured (triangle) arrays are ordered: Vertex (x, y, z) Vertex Normal (x, y, z) Texture Coordinates (u, v) This is the way I've always done it. Should the UVs come before the normals? I'm not sure if it matters. I'd assume that the texturing & lighting units would have a preference, but I can't find anything about it. I certainly can't detect a difference.

    Read the article

  • How to interpolate rotations?

    - by uhuu
    I have two vectors describing rotations; a start rotation A and a target rotation B. How would I best go about interpolating A by a factor F to approach B? Using a simple lerp on the vectors fails to work when more than one dimension needs to be interpolated (i.e. produces undesirable rotations). Maybe building quaternions from the rotation vectors and using slerp is the way to go. But how, then, could I extract a vector describing the new rotation from the resulting quaternion? Thanks in advance.

    Read the article

  • How should I think about perspectives and rotation in OpenGL ES?

    - by Omega
    As I start to write rendering code, how do I want to consider my drawing operations? Will they always be relative to a fixed coordinate system on the screen, or does this change based on the camera perspective? The best example I can try to come up with is say I'm at (0,0,0) and I draw a line to (3,3,3). If I change the perspective +1 on the X axis and conduct the same operation, does it happen at (4,3,3), or am I just getting a new view of the line still being made at (3,3,3)? When doing rotation, am I moving the point from which a frustum emanates, or am I moving the rendering underneath?

    Read the article

  • How can you deflect a direction/magnitude vector based on a direction/magnitude vector and a collided triangle?

    - by JeanOTF
    So, I have a Triangle-AABB collision algorithm and I have it returning the triangle that the AABB collided with. I was hoping with the 3 vectors of the triangle and the direction/magnitude of the movement would let me determine a deflected vector so that when you run against the wall at an angle you move slower, depending on the angle of collision, but along side the wall. This would remove the sticky collision problem with only moving when there is not a collision. Any suggestions or references would be greatly appreciated! Thanks.

    Read the article

  • Getting object coordinates from camera

    - by user566757
    I've implemented a camera in Java using a position vector and three direction vectors so I can use gluLookAt(); moving around in `ghost mode' works fine enough, but I want to add collision detection. I can't seem to figure out how to transform my position vector to coordinates in which OpenGL draws my objects. A rough sketch of my drawing loop is this: glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); camera.setView(); drawer.drawTheScene(); I'm at a loss of how to proceed; looking at the ModelView matrix between calls and my position vector, I haven't found any kind of correlation.

    Read the article

  • How can I make 3ds files' size smaller??

    - by Shaza
    Hey all, Is there any way I can use to make the size of a 3ds file smaller?? I tried to change their length and width using 3dmax but the file size still the same?? I'm using the 3ds files in creating an OpenGl scene so I need to shrink their size as small as I can, any suggestions??

    Read the article

  • Cloning ID3DXMesh with declration that has 12 floats breaks?

    - by meds
    I have the following vertex declration: struct MESHVERTInstanced { float x, y, z; // Position float nx, ny, nz; // Normal float tu, tv; // Texcoord float idx; // index of the vertex! float tanx, tany, tanz; // The tangent const static D3DVERTEXELEMENT9 Decl[6]; static IDirect3DVertexDeclaration9* meshvertinstdecl; }; And I declare it as such: const D3DVERTEXELEMENT9 MESHVERTInstanced::Decl[] = { { 0, 0, D3DDECLTYPE_FLOAT3, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_POSITION, 0 }, { 0, 12, D3DDECLTYPE_FLOAT3, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_NORMAL, 0 }, { 0, 24, D3DDECLTYPE_FLOAT2, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_TEXCOORD, 0 }, { 0, 32, D3DDECLTYPE_FLOAT1, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_TEXCOORD, 1 }, { 0, 36, D3DDECLTYPE_FLOAT3, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_TANGENT, 0 }, D3DDECL_END() }; What I try to do next is copy an ID3DXMesh into another one with the new vertex declaration as such: model->CloneMesh( model->GetOptions(), MESHVERTInstanced::Decl, gd3dDevice, &pTempMesh ); When I try to get the FVF size of pTempMesh (D3DXGetFVFVertexSize(pTempMesh-GetFVF())) I get '0' though the size should be 48. The whole thing is fine if I don't have the last declaration, '{ 0, 36, D3DDECLTYPE_FLOAT3, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_TANGENT, 0 },' in it and the CloneMesh function does not return a FAIL. I've also tried using different declarations such as D3DDECLUSAGE_TEXCOORD and that has worked fine, returning a size of 48. Is there something specific about D3DDECLUSAGE_TANGENT I don't know? I'm at a complete loss as to why this isn't working...

    Read the article

  • Why am I getting ClassNotFoundExpection when I have properly imported said class and am looking at it in its directory?

    - by Strider
    This is my Javac compiling statement: javac -cp "C:\java\code\j3D\j3dcore.jar;C:\java\code\j3D\j3dutils.jar;C:\java\code\j3D\vecmath.jar" Simple.java compiles with no problems. The three jar files (j3dcore, j3dutils, and vecmath) are the essential jar's for my program (or at least I am led to believe according to this official tutorial on J3D For the record I ripped this code almost line from line from this pdf file. jar files are correctly located in referenced locations When I run my Simple program, (java Simple) I am greeted with Exception in thread "main" java.lang.NoClassDefFoundError: javax/media/j3d/Cavas3d Caused by: java.lang.ClassNotFoundExpection: javax.media.j3d.Canvas3D Currently I am staring directly at this Canvas3D.class that is located within j3dcore.jar\javax\media\j3d\ wtfisthis.jpg Here is the source code: //First java3D Program import java.applet.Applet; import java.awt.BorderLayout; import java.awt.Frame; import java.awt.event.*; import com.sun.j3d.utils.applet.MainFrame; import com.sun.j3d.utils.universe.*; import com.sun.j3d.utils.geometry.ColorCube; import javax.media.j3d.*; import javax.vecmath.*; import java.awt.GraphicsConfiguration; public class Simple extends Applet { public Simple() { setLayout(new BorderLayout()); GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration(); Canvas3D canvas3D = new Canvas3D(config); add("Center", canvas3D); BranchGroup scene = createSceneGraph(); scene.compile(); // SimpleUniverse is a Convenience Utility class SimpleUniverse simpleU = new SimpleUniverse(canvas3D); // This moves the ViewPlatform back a bit so the // objects in the scene can be viewed. simpleU.getViewingPlatform().setNominalViewingTransform(); simpleU.addBranchGraph(scene); } // end of HelloJava3Da (constructor) public BranchGroup createSceneGraph() { // Create the root of the branch graph BranchGroup objRoot = new BranchGroup(); // Create a simple shape leaf node, add it to the scene graph. // ColorCube is a Convenience Utility class objRoot.addChild(new ColorCube(0.4)); return objRoot; } public static void main(String args[]){ Simple world = new Simple(); } }` Did I import correctly? Did I incorrectly reference my jar files in my Javac statement? If I clearly see Canvas3D within its correct directory why cant java find it? The first folder in both j3dcore.jar and vecmath.jar is "javax". Is the compiler getting confused? If the compiler is getting confused how do I specify where to find that exact class when referencing it within my source code?

    Read the article

  • Move an object in the direction of a bezier curve?

    - by Sent1nel
    I have an object with which I would like to make follow a bezier curve and am a little lost right now as to how to make it do that based on time rather than the points that make up the curve. .::Current System::. Each object in my scene graph is made from position, rotation and scale vectors. These vectors are used to form their corresponding matrices: scale, rotation and translation. Which are then multiplied in that order to form the local transform matrix. A world transform (Usually the identity matrix) is then multiplied against the local matrix transform. class CObject { public: // Local transform functions Matrix4f GetLocalTransform() const; void SetPosition(const Vector3f& pos); void SetRotation(const Vector3f& rot); void SetScale(const Vector3f& scale); // Local transform Matrix4f m_local; Vector3f m_localPostion; Vector3f m_localRotation; // rotation in degrees (xrot, yrot, zrot) Vector3f m_localScale; } Matrix4f CObject::GetLocalTransform() { Matrix4f out(Matrix4f::IDENTITY); Matrix4f scale(), rotation(), translation(); scale.SetScale(m_localScale); rotation.SetRotationDegrees(m_localRotation); translation.SetTranslation(m_localTranslation); out = scale * rotation * translation; } The big question I have are 1) How do I orientate my object to face the tangent of the Bezier curve? 2) How do I move that object along the curve without just setting objects position to that of a point on the bezier cuve? Heres an overview of the function thus far void CNodeControllerPieceWise::AnimateNode(CObject* pSpatial, double deltaTime) { // Get object latest pos. Vector3f posDelta = pSpatial->GetWorldTransform().GetTranslation(); // Get postion on curve Vector3f pos = curve.GetPosition(m_t); // Get tangent of curve Vector3f tangent = curve.GetFirstDerivative(m_t); } Edit: sorry its not very clear. I've been working on this for ages and its making my brain turn to mush. I want the object to be attached to the curve and face the direction of the curve. As for movement, I want to object to follow the curve based on the time this way it creates smooth movement throughout the curve.

    Read the article

  • DirectX capabilities on different graphics cards

    - by user9876
    I'm writing a Direct3D application, using DirectX 9. Although it works on my PC, I need to make it work on a wide range of systems. I need to know what capabilities I can expect to see on other systems. Is there a list of the DirectX capabilities that graphics cards support? I've found one site, which I'll post as an answer, but it's a bit out of date.

    Read the article

  • Converting OpenGL coordinates to lower UIView (and UIImagePickerController)

    - by John Qualis
    I am new to OpenGL on the iPhone. I am developing an iPhone app similar to a barcode reader but with an extra OpenGL layer. The bottommost layer is UIImagePickerController, then I use UIView on top and draw a rectangle at certain coordinates on the iPhone screen. So far everything is OK. Then I am trying to draw an OpenGL 3-D model in that rectangle. I am able to load a 3-D model in the iPhone based on this code here - http://iphonedevelopment.blogspot.com/2008/12/start-of-wavefront-obj-file-loader.html I am not able to transform the coordinates of the rectangle into OpenGL coordinates. Appreciate any help. Do I need to use a matrix to translate the currentPosition of the 3-D model so it is drawn within myRect? The code is given below. -(void)setupView:(GLView*)view { const GLfloat zNear = 0.01, zFar = 1000.0, fieldOfView = 45.0; GLfloat size; glEnable(GL_DEPTH_TEST); glMatrixMode(GL_PROJECTION); size = zNear * tanf(DEGREES_TO_RADIANS(fieldOfView) / 2.0); CGRect rect = view.bounds; glFrustumf(-size, size, -size / (rect.size.width / rect.size.height), size / (rect.size.width / rect.size.height), zNear, zFar); glViewport(0, 0, rect.size.width, rect.size.height); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glClearColor(0.0f, 0.0f, 0.0f, 0.0f); NSString *path = [[NSBundle mainBundle] pathForResource:@"plane" ofType:@"obj"]; OpenGLWaveFrontObject *theObject = [[OpenGLWaveFrontObject alloc] initWithPath:path]; Vertex3D position; position.z = -8.0; position.y = 3.0; position.x = 2.0; theObject.currentPosition = position; self.plane = theObject; [theObject release]; } - (void)drawView:(GLView*)view; { static GLfloat rotation = 0.0; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glColor4f(0.0, 0.5, 1.0, 1.0); // the coordinates of the rectangle are // myRect.x, myRect.y, myRect.width, myRect.height // Do I need to use a matrix to translate the currentPosition of the // 3-D model so it is drawn within myRect? //glOrthof(-160.0f, 160.0f, -240.0f, 240.0f, -1.0f, 1.0f); [plane drawSelf]; }

    Read the article

  • Efficient quaternion angular velocity

    - by user3736210
    I have an orientation expressed with a quaternion and an angular velocity expressed as either a quaternion or a number (radians per second around the original orientation). I understand how to do this using conversion to axis-angle but that method is rather computationally expensive and is not a realistic option. How would I go about modifying the orientation quaternion given a time interval (in seconds)? I need a solution for both cases (the quaternion and the number).

    Read the article

  • Loading material parameteres from FBX in XNA

    - by M_F
    I've got some material parameters stored in the FBX file (DiffuseFactor, ShininessExponent, SpecularFactor and others), but I can't get to them using Effect.Parameters nor BasicEffect (they've got only the basic stuff - like EmmisiveColor or alpha). I know, that I can try to write a Effect-derived class, but is there any other way? A built-in feature or maybe some half-raw parameters stored somewhere?

    Read the article

  • OFF descriptions

    - by Myx
    Hi: I'd like to make a scene that uses meshes and primitives (such as spheres, cylinders, boxes, etc). I was wondering if there are any recommendations with regard to where I can go to find .off files that describes complex meshes, such as mountains, rocks, trees, animals, etc. Thanks.

    Read the article

  • Adobe Photoshop CS5 vs Photoshop CS5 extended

    - by Edward
    Adobe Photoshop has been an industry standard for most web designers & photographers worldwide. Photoshop CS5 has made photography editing much more refined and the composition process has become much easier than ever before.  To study the advantage of Photoshop CS5 extended over Photoshop CS5 we have written this comparison article, with both a Designer’s & Photographer’s perspective. Hopefully it shall help you in your buying/upgrade decision. Photoshop CS5 Photoshop CS5 has refining feature with powerful photography tools. It made editing process easy as fewer steps are involved to remove noise, add grain, create vignettes, correct lens distortions, sharpen, and create HDR images. It has quick image correction and color and tone control for professional purpose. Intelligent image editing and enhancement , extraordinary advanced compositing has made it a better tool than earlier versions for photographers. It allows users to accelerate workflow with fast performance on 64-bit Windows® and Mac hardware systems and smoother interactions due to more GPU-accelerated features. It also boasts of a state-of-the-art processing with Adobe Photoshop Camera Raw 6 and helps to maximize creative impact. It provides for tremendous precision and freedom. It allows user to easily select intricate image elements, such as hair and create realistic painting effects. It also allows to remove any image element and see the space fill in almost magically. It has easy access to core editing and streamlined work flow and flexible work ambience. It has creative tools and contents. Photoshop CS5 Extended Photoshop CS5 extended is quite innovative and has incorporated 3D elements to 2D artwork directly within digital imaging application, which enables user to do an easy on-ramp to 3D image creation. It also provides for 3D editing. It has intelligent image editing and enhancement. It offers advance composing and has extraordinary painting and drawing toolset. It provides for video and animation designing. It helps to work with specialized images for architecture, manufacturing, engineering, science, and medicine. Where CS5 extended scores over CS5 CS5 extended has many features, which were not included in CS5. These features make it score more over CS5. These features are: Technology for creating 3D extrusion 3D material library and picker Field depth for 3D 3D merging and scene composition improvements 3D workflow improvement Customization of 3D features Image based light source Shadow catcher for shadow creation Enhanced ray tracer Context sensitive widgets, which allows easy control of objects, lights and cameras. Overlays for materials and mesh boundaries Photoshop CS5 extended is far better than CS5 as it incorporates all the features of CS5 and have more advanced features. It allows 3D creation and editing and has other advanced tools to make it better. Redefining the Image-Editing Experience  : A Photographer’s point of View Photoshop CS5 delivers amazing features and creative options so even new users can perform advanced image manipulations and compositions. Breath taking image intelligence behind Content-Aware Fill magically removes any image detail or object, examines the surroundings and seamlessly fills in the space left behind. Lighting, tone and noise of the surrounding area can be matched. New Refine Edge makes nearly-impossible image selections possible. Masking was never easier, the toughest types of edges, such as hair and foliage seem easier to fix. To sum up following are few advantages of CS5 extended over previous versions 64-bit processing Content Aware Fill Refine Edge, “makes nearly-impossible image selections impossible” HDR Pro, including ghost artifact removal and HDR toning, which gives the look of HDR with a single exposure New brush options Improved image management with enhanced Adobe Bridge Lens corrections Improved black-and-white conversions Puppet Warp: Precisely reposition or warp any image element Adobe Camera Raw 6 Upgrade Buy Online Pricing and Availability Adobe Photoshop CS5 and CS5 Extended are available through Adobe Authorized Resellers & the Adobe Store. Estimated street price for Adobe Photoshop CS5 is US$699 and US$999 for Photoshop CS5 Extended. Upgrade pricing and volume licensing are also available. Related posts:10 Free Alternatives for Adobe Photoshop Software Web based Alternatives to Photoshop 15 Useful Adobe Illustrator Tutorials For Designers

    Read the article

  • 3D collision physics. Response when hitting wall, floor or roof

    - by GlamCasvaluir
    I am having problem with the most basic physic response when the player collide with static wall, floor or roof. I have a simple 3D maze, true means solid while false means air: bool bMap[100][100][100]; The player is a sphere. I have keys for moving x++, x--, y++, y-- and diagonal at speed 0.1f (0.1 * ftime). The player can also jump. And there is gravity pulling the player down. Relative movement is saved in: relx, rely and relz. One solid cube on the map is exactly 1.0f width, height and depth. The problem I have is to adjust the player position when colliding with solids, I don't want it to bounce or anything like that, just stop. But if moving diagonal left/up and hitting solid up, the player should continue moving left, sliding along the wall. Before moving the player I save the old player position: oxpos = xpos; oypos = ypos; ozpos = zpos; vec3 direction; direction = vec3(relx, rely, relz); xpos += direction.x*ftime; ypos += direction.y*ftime; zpos += direction.z*ftime; gx = floor(xpos+0.25); gy = floor(ypos+0.25); gz = floor(zpos+0.25); if (bMap[gx][gy][gz] == true) { vec3 normal = vec3(0.0, 0.0, 1.0); // <- Problem. vec3 invNormal = vec3(-normal.x, -normal.y, -normal.z) * length(direction * normal); vec3 wallDir = direction - invNormal; xpos = oxpos + wallDir.x; ypos = oypos + wallDir.y; zpos = ozpos + wallDir.z; } The problem with my version is that I do not know how to chose the correct normal for the cube side. I only have the bool array to look at, nothing else. One theory I have is to use old values of gx, gy and gz, but I do not know have to use them to calculate the correct cube side normal.

    Read the article

  • Windows XP - Security Update for Windows XP (KB923561) (KB946648) (KB956572) (KB958644)

    - by leeand00
    My father's computer has Windows XP, but when I try to install the service packs it always fails. What gives? Here are the errors that I get in the event log: Date: 2/6/2010 Time: 12:02:18 AM Type: Error User: N/A Computer: EVO Source: Windows Update Agent Category: Installation Event ID: 20 Installation Failure: Windows failed to install the following update with error 0x80070002: Security Update for Windows XP (KB946648). For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 0000: 57 69 6e 33 32 48 52 65 Win32HRe 0008: 73 75 6c 74 3d 30 78 38 sult=0x8 0010: 30 30 37 30 30 30 32 20 0070002 0018: 55 70 64 61 74 65 49 44 UpdateID 0020: 3d 7b 38 33 44 31 41 44 ={83D1AD 0028: 46 35 2d 37 37 39 44 2d F5-779D- 0030: 34 30 31 36 2d 38 43 33 4016-8C3 0038: 31 2d 35 34 39 32 37 30 1-549270 0040: 46 36 37 42 33 46 7d 20 F67B3F} 0048: 52 65 76 69 73 69 6f 6e Revision 0050: 4e 75 6d 62 65 72 3d 31 Number=1 0058: 30 34 20 00 04 . Date: 2/6/2010 Time: 12:02:18 AM Type: Error User: N/A Computer: EVO Source: Windows Update Agent Catagory: Installation Event ID: 20 Installation Failure: Windows failed to install the following update with error 0x80070002: Security Update for Windows XP (KB956572). For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 0000: 57 69 6e 33 32 48 52 65 Win32HRe 0008: 73 75 6c 74 3d 30 78 38 sult=0x8 0010: 30 30 37 30 30 30 32 20 0070002 0018: 55 70 64 61 74 65 49 44 UpdateID 0020: 3d 7b 44 46 32 46 30 41 ={DF2F0A 0028: 39 38 2d 36 45 33 35 2d 98-6E35- 0030: 34 33 37 39 2d 41 42 33 4379-AB3 0038: 33 2d 41 30 33 30 33 45 3-A0303E 0040: 46 37 34 42 32 41 7d 20 F74B2A} 0048: 52 65 76 69 73 69 6f 6e Revision 0050: 4e 75 6d 62 65 72 3d 31 Number=1 0058: 30 32 20 00 02 . Date: 2/6/2010 Time: 12:02:18 AM Type: Error User: N/A Computer EVO Source: Windows Update Agent Event ID: 20 Installation Failure: Windows failed to install the following update with error 0x80070002: Security Update for Windows XP (KB958644). For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 0000: 57 69 6e 33 32 48 52 65 Win32HRe 0008: 73 75 6c 74 3d 30 78 38 sult=0x8 0010: 30 30 37 30 30 30 32 20 0070002 0018: 55 70 64 61 74 65 49 44 UpdateID 0020: 3d 7b 39 33 39 37 41 32 ={9397A2 0028: 31 46 2d 32 34 36 43 2d 1F-246C- 0030: 34 35 33 42 2d 41 43 30 453B-AC0 0038: 35 2d 36 35 42 46 34 46 5-65BF4F 0040: 43 36 42 36 38 42 7d 20 C6B68B} 0048: 52 65 76 69 73 69 6f 6e Revision 0050: 4e 75 6d 62 65 72 3d 31 Number=1 0058: 30 31 20 00 01 . Date: 2/6/2010 Time: 12:02:18 AM Type: Error User: N/A Computer: EVO Source: Windows Update Agent Category: Installation Event ID: 20 Installation Failure: Windows failed to install the following update with error 0x80070002: Security Update for Windows XP (KB923561). For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 0000: 57 69 6e 33 32 48 52 65 Win32HRe 0008: 73 75 6c 74 3d 30 78 38 sult=0x8 0010: 30 30 37 30 30 30 32 20 0070002 0018: 55 70 64 61 74 65 49 44 UpdateID 0020: 3d 7b 33 31 30 41 34 43 ={310A4C 0028: 30 38 2d 35 39 33 44 2d 08-593D- 0030: 34 31 41 33 2d 42 42 35 41A3-BB5 0038: 37 2d 38 33 42 33 38 36 7-83B386 0040: 44 37 37 33 42 35 7d 20 D773B5} 0048: 52 65 76 69 73 69 6f 6e Revision 0050: 4e 75 6d 62 65 72 3d 31 Number=1 0058: 30 33 20 00 03 . Thank you, Andrew

    Read the article

  • 3D Ball Physics Theory: collision response on ground and against walls?

    - by David
    I'm really struggling to get a strong grasp on how I should be handling collision response in a game engine I'm building around a 3D ball physics concept. Think Monkey Ball as an example of the type of gameplay. I am currently using sphere-to-sphere broad phase, then AABB to OBB testing (the final test I am using right now is one that checks if one of the 8 OBB points crosses the planes of the object it is testing against). This seems to work pretty well, and I am getting back: Plane that object is colliding against (with a point on the plane, the plane's normal, and the exact point of intersection. I've tried what feels like dozens of different high-level strategies for handling these collisions, without any real success. I think my biggest problem is understanding how to handle collisions against walls in the x-y axes (left/right, front/back), which I want to have elasticity, and the ground (z-axis) where I want an elastic reaction if the ball drops down, but then for it to eventually normalize and be kept "on the ground" (not go into the ground, but also not continue bouncing). Without kluging something together, I'm positive there is a good way to handle this, my theories just aren't getting me all the way there. For physics modeling and movement, I am trying to use a Euler based setup with each object maintaining a position (and destination position prior to collision detection), a velocity (which is added onto the position to determine the destination position), and an acceleration (which I use to store any player input being put on the ball, as well as gravity in the z coord). Starting from when I detect a collision, what is a good way to approach the response to get the expected behavior in all cases? Thanks in advance to anyone taking the time to assist... I am grateful for any pointers, and happy to post any additional info or code if it is useful. UPDATE Based on Steve H's and eBusiness' responses below, I have adapted my collision response to what makes a lot more sense now. It was close to right before, but I didn't have all the right pieces together at the right time! I have one problem left to solve, and that is what is causing the floor collision to hit every frame. Here's the collision response code I have now for the ball, then I'll describe the last bit I'm still struggling to understand. // if we are moving in the direction of the plane (against the normal)... if (m_velocity.dot(intersection.plane.normal) <= 0.0f) { float dampeningForce = 1.8f; // eventually create this value based on mass and acceleration // Calculate the projection velocity PVRTVec3 actingVelocity = m_velocity.project(intersection.plane.normal); m_velocity -= actingVelocity * dampeningForce; } // Clamp z-velocity to zero if we are within a certain threshold // -- NOTE: this was an experimental idea I had to solve the "jitter" bug I'll describe below float diff = 0.2f - abs(m_velocity.z); if (diff > 0.0f && diff <= 0.2f) { m_velocity.z = 0.0f; } // Take this object to its new destination position based on... // -- our pre-collision position + vector to the collision point + our new velocity after collision * time // -- remaining after the collision to finish the movement m_destPosition = m_position + intersection.diff + (m_velocity * intersection.tRemaining * GAMESTATE->dt); The above snippet is run after a collision is detected on the ball (collider) with a collidee (floor in this case). With a dampening force of 1.8f, the ball's reflected "upward" velocity will eventually be overcome by gravity, so the ball will essentially be stuck on the floor. THIS is the problem I have now... the collision code is running every frame (since the ball's z-velocity is constantly pushing it a collision with the floor below it). The ball is not technically stuck, I can move it around still, but the movement is really goofy because the velocity and position keep getting affected adversely by the above snippet. I was experimenting with an idea to clamp the z-velocity to zero if it was "close to zero", but this didn't do what I think... probably because the very next frame the ball gets a new gravity acceleration applied to its velocity regardless (which I think is good, right?). Collisions with walls are as they used to be and work very well. It's just this last bit of "stickiness" to deal with. The camera is constantly jittering up and down by extremely small fractions too when the ball is "at rest". I'll keep playing with it... I like puzzles like this, especially when I think I'm close. Any final ideas on what I could be doing wrong here? UPDATE 2 Good news - I discovered I should be subtracting the intersection.diff from the m_position (position prior to collision). The intersection.diff is my calculation of the difference in the vector of position to destPosition from the intersection point to the position. In this case, adding it was causing my ball to always go "up" just a little bit, causing the jitter. By subtracting it, and moving that clamper for the velocity.z when close to zero to being above the dot product (and changing the test from <= 0 to < 0), I now have the following: // Clamp z-velocity to zero if we are within a certain threshold float diff = 0.2f - abs(m_velocity.z); if (diff > 0.0f && diff <= 0.2f) { m_velocity.z = 0.0f; } // if we are moving in the direction of the plane (against the normal)... float dotprod = m_velocity.dot(intersection.plane.normal); if (dotprod < 0.0f) { float dampeningForce = 1.8f; // eventually create this value based on mass and acceleration? // Calculate the projection velocity PVRTVec3 actingVelocity = m_velocity.project(intersection.plane.normal); m_velocity -= actingVelocity * dampeningForce; } // Take this object to its new destination position based on... // -- our pre-collision position + vector to the collision point + our new velocity after collision * time // -- remaining after the collision to finish the movement m_destPosition = m_position - intersection.diff + (m_velocity * intersection.tRemaining * GAMESTATE->dt); UpdateWorldMatrix(m_destWorldMatrix, m_destOBB, m_destPosition, false); This is MUCH better. No jitter, and the ball now "rests" at the floor, while still bouncing off the floor and walls. The ONLY thing left is that the ball is now virtually "stuck". He can move but at a much slower rate, likely because the else of my dot product test is only letting the ball move at a rate multiplied against the tRemaining... I think this is a better solution than I had previously, but still somehow not the right idea. BTW, I'm trying to journal my progress through this problem for anyone else with a similar situation - hopefully it will serve as some help, as many similar posts have for me over the years.

    Read the article

< Previous Page | 40 41 42 43 44 45 46 47 48 49 50 51  | Next Page >