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  • Proper way to use a RenderTarget2D to draw multiple textures?

    - by TheBroodian
    In the process of trying to resolve a split screen issue, I've been trying to use a RenderTarget2D to draw a portion of my scene to a Texture2D, and then again to another Texture2D, but the end result of both Texture2D's is coming out the same. Can anybody tell me what I'm doing wrong? Texture2D camera1Render; Texture2D camera2Render; GraphicsDevice.SetRenderTarget(RenderTarget); GraphicsDevice.Clear(Color.Transparent); map.Draw(mapDisplayDevice, Camera1, new Location(0, 0), false); camera1Render = RenderTarget; GraphicsDevice.Clear(Color.Transparent); map.Draw(mapDisplayDevice, Camera2, new Location(0, 0), false); camera2Render = RenderTarget; SetRenderTarget(null);

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  • Is good practice to optimize FPS even when it's above the lower limit to give illusion of movement?

    - by rraallvv
    I started over 50 FPS on the iPhone, but now I'm bellow 30 PFS, I've seen most iPhone games clamped to either 60 or 30 FPS, even when 24 or less would give the illusion of movement. I've concidered my limit to be a little bit over 15 FPS, in fact my physics simulation is updated at that rate (15.84 steps/s) as that is the lowest that still give fluid movement, a bit lower gives jerky motion. Is there a practical reason why to clamp FPS way above the lower limit? Update: The following image could help to clarify I can independently set the physic simulation step, frame rate, and simulation interval update. My concern is why should I clamp any of those to values greater than the minimum? For instance to conserve battery life I could just to choose the lower limits, but it seems that 60 or 30 FPS are the most used values.

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  • Biome Transition in a Grid & Borderless World

    - by API-Beast
    I have a universe: a list of "Systems", each with their own center, type and radius. A small part of such a universe could look like this: Systems: Can be very close to a different system, e.g. overlap Can be inside another, much bigger system Can be very far away from any other systems Spawn system specific entities and particles inside the system radius Have some properties like background color So far so good. However, the player can fly around freely, inside and outside of systems, in real time. How do I interpolate and determine things like the background color now, depending on camera position? E.g. if you are halfway between a green and a red system you should see a background halfway between red and green, or if you are inside a lilac system near the center and at the border of a green system you should get a mostly lilac background etc.

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  • How to implement explosion in OpenGL?

    - by Chan
    I'm relatively new to OpenGL and I'm clueless how to implement explosion. So could anyone give me some ideas how to start? Suppose the explosion occurs at location $(x, y, z)$, then I'm thinking of randomly generate a collection of vectors with $(x, y, z)$ as origin, then draw some particle (glutSolidCube) which move along this vector for some period of time, says after 1000 updates, it disappear. Is this approach feasible? A minimal example would be greatly appreciated.

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  • 2D wave-like sprite movement XNA

    - by TheBroodian
    I'm trying to create a particle that will 'circle' my character. When the particle is created, it's given a random position in relation to my character, and a box to provide boundaries for how far left or right this particle should circle. When I use the phrase 'circle', I'm referring to a simulated circling, i.e., when moving to the right, the particle will appear in front of my character, when passing back to the left, the particle will appear behind my character. That may have been too much context, so let me cut to the chase: In essence, the path I would like my particle to follow would be akin to a sine wave, with the left and right sides of the provided rectangle being the apexes of the wave. The trouble I'm having is that the position of the particle will be random, so it will never be produced at the same place within the wave twice, but I have no idea how to create this sort of behavior procedurally.

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  • Finding closest object to a location within a specific perpendicular distance to direction vector

    - by Sniper
    I have a location and a direction vector indicating facing, I want to find the closest object to that location that is within some tolerance distance (perpendicular distance) to the ray formed by the location and direction vector. Basically I want to get the object that is being aimed at. I have thought about finding all objects within a box and then finding the closest object to my vector from them results, but I am sure that there is a more efficient way. The Z axis is optional, the objects are most likely within a few meters of the search vector.

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  • how do I set quad buffering with jogl 2.0

    - by tony danza
    I'm trying to create a 3d renderer for stereo vision with quad buffering with Processing/Java. The hardware I'm using is ready for this so that's not the problem. I had a stereo.jar library in jogl 1.0 working for Processing 1.5, but now I have to use Processing 2.0 and jogl 2.0 therefore I have to adapt the library. Some things are changed in the source code of Jogl and Processing and I'm having a hard time trying to figure out how to tell Processing I want to use quad buffering. Here's the previous code: public class Theatre extends PGraphicsOpenGL{ protected void allocate() { if (context == null) { // If OpenGL 2X or 4X smoothing is enabled, setup caps object for them GLCapabilities capabilities = new GLCapabilities(); // Starting in release 0158, OpenGL smoothing is always enabled if (!hints[DISABLE_OPENGL_2X_SMOOTH]) { capabilities.setSampleBuffers(true); capabilities.setNumSamples(2); } else if (hints[ENABLE_OPENGL_4X_SMOOTH]) { capabilities.setSampleBuffers(true); capabilities.setNumSamples(4); } capabilities.setStereo(true); // get a rendering surface and a context for this canvas GLDrawableFactory factory = GLDrawableFactory.getFactory(); drawable = factory.getGLDrawable(parent, capabilities, null); context = drawable.createContext(null); // need to get proper opengl context since will be needed below gl = context.getGL(); // Flag defaults to be reset on the next trip into beginDraw(). settingsInited = false; } else { // The following three lines are a fix for Bug #1176 // http://dev.processing.org/bugs/show_bug.cgi?id=1176 context.destroy(); context = drawable.createContext(null); gl = context.getGL(); reapplySettings(); } } } This was the renderer of the old library. In order to use it, I needed to do size(100, 100, "stereo.Theatre"). Now I'm trying to do the stereo directly in my Processing sketch. Here's what I'm trying: PGraphicsOpenGL pg = ((PGraphicsOpenGL)g); pgl = pg.beginPGL(); gl = pgl.gl; glu = pg.pgl.glu; gl2 = pgl.gl.getGL2(); GLProfile profile = GLProfile.get(GLProfile.GL2); GLCapabilities capabilities = new GLCapabilities(profile); capabilities.setSampleBuffers(true); capabilities.setNumSamples(4); capabilities.setStereo(true); GLDrawableFactory factory = GLDrawableFactory.getFactory(profile); If I go on, I should do something like this: drawable = factory.getGLDrawable(parent, capabilities, null); but drawable isn't a field anymore and I can't find a way to do it. How do I set quad buffering? If I try this: gl2.glDrawBuffer(GL.GL_BACK_RIGHT); it obviously doesn't work :/ Thanks.

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  • Efficiently separating Read/Compute/Write steps for concurrent processing of entities in Entity/Component systems

    - by TravisG
    Setup I have an entity-component architecture where Entities can have a set of attributes (which are pure data with no behavior) and there exist systems that run the entity logic which act on that data. Essentially, in somewhat pseudo-code: Entity { id; map<id_type, Attribute> attributes; } System { update(); vector<Entity> entities; } A system that just moves along all entities at a constant rate might be MovementSystem extends System { update() { for each entity in entities position = entity.attributes["position"]; position += vec3(1,1,1); } } Essentially, I'm trying to parallelise update() as efficiently as possible. This can be done by running entire systems in parallel, or by giving each update() of one system a couple of components so different threads can execute the update of the same system, but for a different subset of entities registered with that system. Problem In reality, these systems sometimes require that entities interact(/read/write data from/to) each other, sometimes within the same system (e.g. an AI system that reads state from other entities surrounding the current processed entity), but sometimes between different systems that depend on each other (i.e. a movement system that requires data from a system that processes user input). Now, when trying to parallelize the update phases of entity/component systems, the phases in which data (components/attributes) from Entities are read and used to compute something, and the phase where the modified data is written back to entities need to be separated in order to avoid data races. Otherwise the only way (not taking into account just "critical section"ing everything) to avoid them is to serialize parts of the update process that depend on other parts. This seems ugly. To me it would seem more elegant to be able to (ideally) have all processing running in parallel, where a system may read data from all entities as it wishes, but doesn't write modifications to that data back until some later point. The fact that this is even possible is based on the assumption that modification write-backs are usually very small in complexity, and don't require much performance, whereas computations are very expensive (relatively). So the overhead added by a delayed-write phase might be evened out by more efficient updating of entities (by having threads work more % of the time instead of waiting). A concrete example of this might be a system that updates physics. The system needs to both read and write a lot of data to and from entities. Optimally, there would be a system in place where all available threads update a subset of all entities registered with the physics system. In the case of the physics system this isn't trivially possible because of race conditions. So without a workaround, we would have to find other systems to run in parallel (which don't modify the same data as the physics system), other wise the remaining threads are waiting and wasting time. However, that has disadvantages Practically, the L3 cache is pretty much always better utilized when updating a large system with multiple threads, as opposed to multiple systems at once, which all act on different sets of data. Finding and assembling other systems to run in parallel can be extremely time consuming to design well enough to optimize performance. Sometimes, it might even not be possible at all because a system just depends on data that is touched by all other systems. Solution? In my thinking, a possible solution would be a system where reading/updating and writing of data is separated, so that in one expensive phase, systems only read data and compute what they need to compute, and then in a separate, performance-wise cheap, write phase, attributes of entities that needed to be modified are finally written back to the entities. The Question How might such a system be implemented to achieve optimal performance, as well as making programmer life easier? What are the implementation details of such a system and what might have to be changed in the existing EC-architecture to accommodate this solution?

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  • Precision loss when transforming from cartesian to isometric

    - by Justin Skiles
    My goal is to display a tile map in isometric projection. This tile map has 25 tiles across and 25 tiles down. Each tile is 32x32. See below for how I'm accomplishing this. World Space World Space to Screen Space Rotation (45 degrees) Using a 2D rotation matrix, I use the following: double rotation = Math.PI / 4; double rotatedX = ((tileWorldX * Math.Cos(rotation)) - ((tileWorldY * Math.Sin(rotation))); double rotatedY = ((tileWorldX * Math.Sin(rotation)) + (tileWorldY * Math.Cos(rotation))); World Space to Screen Space Scale (Y-axis reduced by 50%) Here I simply scale down the Y value by a factor of 0.5. Problem And it works, kind of. There are some tiny 1px-2px gaps between some of the tiles when rendering. I think there's some precision loss somewhere, or I'm not understanding how to get these tiles to fit together perfectly. I'm not truncating or converting my values to non-decimal types until I absolutely have to (when I pass to the render method, which only takes integers). I'm not sure how to guarantee pixel perfect rendering precision when I'm rotating and scaling on a level of higher precision. Any advice? Do I need to supply for information?

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  • How to snap a 2D Quad to the mouse cursor using OpenGL 3.0/WIN32?

    - by NoobScratcher
    I've been having issues trying to snap a 2D Quad to the mouse cursor position I'm able : 1.) To get values into posX, posY, posZ 2.) Translate with the values from those 3 variables But the quad positioning I'm not able to do correctly in such a way that the 2D Quad is near the mouse cursor using those values from those 3 variables eg."posX, posY, posZ" I need the mouse cursor in the center of the 2D Quad. I'm hoping someone can help me achieve this. I've tried searching around with no avail. Heres the function that is ment to do the snapping but instead creates weird flicker or shows nothing at all only the 3d models show up : void display() { glClearColor(0.0,0.0,0.0,1.0); glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); for(std::vector<GLuint>::iterator I = cube.begin(); I != cube.end(); ++I) { glCallList(*I); } if(DrawArea == true) { glReadPixels(winX, winY, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &winZ); cerr << winZ << endl; glGetDoublev(GL_MODELVIEW_MATRIX, modelview); glGetDoublev(GL_PROJECTION_MATRIX, projection); glGetIntegerv(GL_VIEWPORT, viewport); gluUnProject(winX, winY, winZ , modelview, projection, viewport, &posX, &posY, & posZ); glBindTexture(GL_TEXTURE_2D, DrawAreaTexture); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); glTexImage2D (GL_TEXTURE_2D, 0, GL_RGB, DrawAreaSurface->w, DrawAreaSurface->h, 0, GL_RGBA, GL_UNSIGNED_BYTE, DrawAreaSurface->pixels); glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, DrawAreaTexture); glTranslatef(posX , posY, posZ); glBegin(GL_QUADS); glTexCoord2f (0.0, 0.0); glVertex3f(0.5, 0.5, 0); glTexCoord2f (1.0, 0.0); glVertex3f(0, 0.5, 0); glTexCoord2f (1.0, 1.0); glVertex3f(0, 0, 0); glTexCoord2f (0.0, 1.0); glVertex3f(0.5, 0, 0); glEnd(); } SwapBuffers(hDC); } I'm using : OpenGL 3.0 WIN32 API C++ GLSL if you really want the full source here it is - http://pastebin.com/1Ncm9HNf , Its pretty messy.

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  • Rotate 3D Model from a custom position

    - by Nipuna Silva
    I have a 3D Model like above in which i want to rotate it from a given location(pointed in red) but I can only rotate it from the middle. How can I rotate it from a custom point. Edit: I successfully able to rotate the model from the below position by getting the radius of the model and applying it to the world matrix Vector3 point = new Vector3(-radius, 0, 0); world = Matrix.CreateTranslation(-radius, 0, 0); But now I cannot change the position of the object and it always centered in middle of the screen. I think that's because i applied the above code. How can I place it anywhere I want?

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  • Frame timing for GLFW versus GLUT

    - by linello
    I need a library which ensures me that the timing between frames are more constant as possible during an experiment of visual psychophics. This is usually done synchronizing the refresh rate of the screen with the main loop. For example if my monitor runs at 60Hz I would like to specify that frequency to my framework. For example if my gameloop is the following void gameloop() { // do some computation printDeltaT(); Flip buffers } I would like to have printed a constant time interval. Is it possible with GLFW?

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  • How is the iOS support in UDK compared to Unity?

    - by Joe
    I have some significant experience in Unity for web clients, but I'm skeptical about the 3K$ price tag to create/deploy iOS games. I noticed UDK now supports iOS, and appears to have "free" version control- and it's only 100$ from what I can tell. My primary question is: Does UDK make iOS development and deployment easy, or do you have to jump through a couple of hoops to make it work? A few side questions not worth another post: How hard is the transition from Unity to UDK? Is UnrealScript easy to pick up from a C/C# background? Does the UDK have good documentation compared to Unity?

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  • Best way to detect if vec3 is between vec3(x) and vec3(y) in glsl

    - by elect
    As titled I am sampling from a texture and if the color is somehow gray [vec3(.8), vec3(.9)] and an uniform is 1 I need to substitute that color with another one I am not a glsl veteran but I am pretty sure there is a more elegant and compact (without mentioning faster) way than this: vec3 textureColor = texture(texture0, oUV); if(settings.w == 1 && textureColor.r > .8 && textureColor.r < .9 && textureColor.g > .8 && textureColor.g < .9 && textureColor.b > .8 && textureColor.b < .9)

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  • Writing to a structured buffer with a compute shader (D3D11)

    - by Vertexwahn
    I have some problems writing to a structured buffer. First I create a structured buffer that is filled with float values beginning from 0 to 99. Afterwards a copy the structured buffer to a CPU accessible buffer is made to print the content of the structured buffer to the console. The output is as expected (Numbers 0 to 99 appear on the console). Afterwards I use a compute shader that should change the contents of the structured buffer: RWStructuredBuffer<float> Result : register( u0 ); [numthreads(1, 1, 1)] void CS_main( uint3 GroupId : SV_GroupID ) { Result[GroupId.x] = GroupId.x * 10; } But the compute shader does not change the contents of the structured buffer. The source code can be found here (main.cpp): https://bitbucket.org/Vertexwahn/cmakedemos/src/4abb067afd5781b87a553c4c720956668adca22a/D3D11ComputeShader/src/main.cpp?at=default FillCS.hlsl: https://bitbucket.org/Vertexwahn/cmakedemos/src/4abb067afd5781b87a553c4c720956668adca22a/D3D11ComputeShader/src/FillCS.hlsl?at=default

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  • Shadowmap first phase and shaders

    - by KaiserJohaan
    I am using OpenGL 3.3 and am tryin to implement shadow mapping using cube maps. I have a framebuffer with a depth attachment and a cube map texture. My question is how to design the shaders for the first pass, when creating the shadowmap. This is my vertex shader: in vec3 position; uniform mat4 lightWVP; void main() { gl_Position = lightWVP * vec4(position, 1.0); } Now, do I even need a fragment shader in this shader pass? from what I understand after reading http://www.opengl.org/wiki/Fragment_Shader, by default gl_FragCoord.z is written to the currently attached depth component (to which my cubemap texture is bound to). Thus I shouldnt even need a fragment shader for this pass and from what I understand, there is no other work to do in the fragment shader other than writing this value. Is this correct?

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  • Using a permutation table for simplex noise without storing it

    - by J. C. Leitão
    Generating Simplex noise requires a permutation table for randomisation (e.g. see this question or this example). In some applications, we need to persist the state of the permutation table. This can be done by creating the table, e.g. using def permutation_table(seed): table_size = 2**10 # arbitrary for this question l = range(1, table_size + 1) random.seed(seed) # ensures the same shuffle for a given seed random.shuffle(l) return l + l # see shared link why l + l; is a detail and storing it. Can we avoid storing the full table by generating the required elements every time they are required? Specifically, currently I store the table and call it using table[i] (table is a list). Can I avoid storing it by having a function that computes the element i, e.g. get_table_element(seed, i). I'm aware that cryptography already solved this problem using block cyphers, however, I found it too complex to go deep and implement a block cypher. Does anyone knows a simple implementation of a block cypher to this problem?

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  • How can I gain access to a player instance in a Minecraft mod?

    - by Andrew Graber
    I'm creating Minecraft mod with a pickaxe that takes away experience when you break a block. The method for taking away experience from a player is addExperience on EntityPlayer, so I need to get an instance of EntityPlayer for the player using my pickaxe when the pickaxe breaks a block, so that I can remove the appropriate amount of experience. My pickaxe class currently looks like this: public class ExperiencePickaxe extends ItemPickaxe { public ExperiencePickaxe(int ItemID, EnumToolMaterial material){ super(ItemID, material); } public boolean onBlockDestroyed(ItemStack par1ItemStack, World par2World, int par3, int par4, int par5, int par6, EntityLiving par7EntityLiving) { if ((double)Block.blocksList[par3].getBlockHardness(par2World, par4, par5, par6) != 0.0D) { EntityPlayer e = new EntityPlayer(); // create an instance e.addExperience(-1); } return true; } } Obviously, I cannot actually create a new EntityPlayer since it is an abstract class. How can I get access to the player using my pickaxe?

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  • Marshalling C# Structs into DX11 cbuffers

    - by Craig
    I'm having some issues with the packing of my structure in C# and passing them through to cbuffers I have registered in HLSL. When I pack my struct in one manner the information seems to be able to pass to the shader: [StructLayout(LayoutKind.Explicit, Size = 16)] internal struct TestStruct { [FieldOffset(0)] public Vector3 mEyePosition; [FieldOffset(12)] public int type; } This works perfectly when used against this HLSL fragment: cbuffer PerFrame : register(b0) { Vector3 eyePos; int type; } float3 GetColour() { float3 returnColour = float(0.0f, 0.0f, 0.0f); switch(type) { case 0: returnColour = float3(1.0f, 0.0f, 0.0f); break; case 1: returnColour = float3(0.0f, 1.0f, 0.0f); break; case 2: returnColour = float3(0.0f, 0.0f, 1.0f); break; } return returnColour; } However, when I use the following structure definitions... // Note this is 16 because HLSL packs in 4 float 'chunks'. // It is also simplified, but still demonstrates the problem. [StructLayout(Layout.Explicit, Size = 16)] internal struct InternalTestStruct { [FieldOffset(0)] public int type; } [StructLayout(LayoutKind.Explicit, Size = 32)] internal struct TestStruct { [FieldOffset(0)] public Vector3 mEyePosition; //Missing 4 bytes here for correct packing. [FieldOffset(16)] public InternalTestStruct mInternal; } ... the following HLSL fragment no longer works. struct InternalType { int type; } cbuffer PerFrame : register(b0) { Vector3 eyePos; InternalType internalStruct; } float3 GetColour() { float3 returnColour = float(0.0f, 0.0f, 0.0f); switch(internaltype.type) { case 0: returnColour = float3(1.0f, 0.0f, 0.0f); break; case 1: returnColour = float3(0.0f, 1.0f, 0.0f); break; case 2: returnColour = float3(0.0f, 0.0f, 1.0f); break; } return returnColour; } Is there a problem with the way I am packing the struct, or is it another issue? To re-iterate: I can pass a struct in a cbuffer so long as it does not contain a nested struct.

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  • Inverse projection: question about w coordinate

    - by fayeWilly
    I have to perform in shader an inverse projection from a u/v of a render target. What I do is: Get NDC as 2*(u,v,depth) - 1 Then world space as tmp = (P*V)^-1 * (NDC,1.0); world space = tmp/tmp.w; This apparently works, but I am confused about the w division there. Why this work? Shouldn't be a multiplication by a w somewhere (as in the "forward" pipeline there is the perpsective division?) Thank you, Faye

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  • backface culling error (in world space)

    - by acrilige
    I write simple software renderer. In my pipeline i have stage of backface culling. But looks like it has some error (see picture). I perform culling right after world transformation (is it correct?). (i can't insert picture in post coz i don't have enough points, so i just upload it (cube model): http://imageshack.us/photo/my-images/705/bcerror.png/) Vector3F view_dir(0.0f, 0.0f, 1.0f); std::vector<Triangle> to_remove; for (Triangle &t : m_triangles) { Vector4F e1 = t.v2 - t.v1; Vector4F e2 = t.v3 - t.v1; Vector3F normal( e1.y * e2.z - e1.z * e2.y, e1.z * e2.x - e1.x * e2.z, e1.x * e2.y - e1.y * e2.x ); normal.Normalize(); float dot = Dot(view_dir, normal); if (dot <= 0) to_remove.push_back(t); } for (Triangle& t : to_remove) m_triangles.erase(std::remove(m_triangles.begin(), m_triangles.end(), t), m_triangles.end()); Camera sits in origin and points in screen (RH). What is the reason? For better explanation i upload picture with cube rotation screenshots: http://imageshack.us/photo/my-images/842/bcmove.png/ UPDATED: The error occurs only when triangle has non-zero offset from origin UPDATED 2: If i process backface culling in clip space (after transforming all vertices with view and projection matrix), and just check z coordinate of triangle normal - it works perfect... Can i perform culing RIGHT BEFORE view/proj transforms? In this case looks like culling will not depends of projection and it's not right?.. UPDATED 3: I found answer and will post it in two hours - again coz of reputation lack.

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  • Numerically stable(ish) method of getting Y-intercept of mouse position?

    - by Fraser
    I'm trying to unproject the mouse position to get the position on the X-Z plane of a ray cast from the mouse. The camera is fully controllable by the user. Right now, the algorithm I'm using is... Unproject the mouse into the camera to get the ray: Vector3 p1 = Vector3.Unproject(new Vector3(x, y, 0), 0, 0, width, height, nearPlane, farPlane, viewProj; Vector3 p2 = Vector3.Unproject(new Vector3(x, y, 1), 0, 0, width, height, nearPlane, farPlane, viewProj); Vector3 dir = p2 - p1; dir.Normalize(); Ray ray = Ray(p1, dir); Then get the Y-intercept by using algebra: float t = -ray.Position.Y / ray.Direction.Y; Vector3 p = ray.Position + t * ray.Direction; The problem is that the projected position is "jumpy". As I make small adjustments to the mouse position, the projected point moves in strange ways. For example, if I move the mouse one pixel up, it will sometimes move the projected position down, but when I move it a second pixel, the project position will jump back to the mouse's location. The projected location is always close to where it should be, but it does not smoothly follow a moving mouse. The problem intensifies as I zoom the camera out. I believe the problem is caused by numeric instability. I can make minor improvements to this by doing some computations at double precision, and possibly abusing the fact that floating point calculations are done at 80-bit precision on x86, however before I start micro-optimizing this and getting deep into how the CLR handles floating point, I was wondering if there's an algorithmic change I can do to improve this? EDIT: A little snooping around in .NET Reflector on SlimDX.dll: public static Vector3 Unproject(Vector3 vector, float x, float y, float width, float height, float minZ, float maxZ, Matrix worldViewProjection) { Vector3 coordinate = new Vector3(); Matrix result = new Matrix(); Matrix.Invert(ref worldViewProjection, out result); coordinate.X = (float) ((((vector.X - x) / ((double) width)) * 2.0) - 1.0); coordinate.Y = (float) -((((vector.Y - y) / ((double) height)) * 2.0) - 1.0); coordinate.Z = (vector.Z - minZ) / (maxZ - minZ); TransformCoordinate(ref coordinate, ref result, out coordinate); return coordinate; } // ... public static void TransformCoordinate(ref Vector3 coordinate, ref Matrix transformation, out Vector3 result) { Vector3 vector; Vector4 vector2 = new Vector4 { X = (((coordinate.Y * transformation.M21) + (coordinate.X * transformation.M11)) + (coordinate.Z * transformation.M31)) + transformation.M41, Y = (((coordinate.Y * transformation.M22) + (coordinate.X * transformation.M12)) + (coordinate.Z * transformation.M32)) + transformation.M42, Z = (((coordinate.Y * transformation.M23) + (coordinate.X * transformation.M13)) + (coordinate.Z * transformation.M33)) + transformation.M43 }; float num = (float) (1.0 / ((((transformation.M24 * coordinate.Y) + (transformation.M14 * coordinate.X)) + (coordinate.Z * transformation.M34)) + transformation.M44)); vector2.W = num; vector.X = vector2.X * num; vector.Y = vector2.Y * num; vector.Z = vector2.Z * num; result = vector; } ...which seems to be a pretty standard method of unprojecting a point from a projection matrix, however this serves to introduce another point of possible instability. Still, I'd like to stick with the SlimDX Unproject routine rather than writing my own unless it's really necessary.

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  • Simple project - make a 3D box tumble and fall to the ground [closed]

    - by Dominic Bou-Samra
    Possible Duplicate: Resources to learn programming rigid body simulation Hi guys, I want to try learning rigid-body dynamic simulation. I have done a fluid and cloth simulation before, but never anything rigid. My maths knowledge is limited in that I don't know the notation that well. Are there any good cliff-notes, tutorials, guides on how I would accomplish a simple task like this? I don't want a super complex pdf that's only a little relevant. Thanks.

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  • How can I use the dualforward parameter in my unity shader to use lightmaps and normal maps together?

    - by Raphaeltm
    I'm using the free version of unity and I would like to combine lightmaps with specularity and normal maps. After doing a -bunch- of research, I've figured out that there doesn't seem to be any easy way to do this in the free version of unity, which doesn't support deferred rendering/easy use of dual lightmaps. However, it looks like it's possible, by writing a custom shader, using the "dualforward" parameter in a shader, switching the lightmapping mode to "dual lightmaps" and turning on "Use in forward ren." (basically, writing a shader that specifies the use of dual lightmaps, which should allow for a combination of lightmaps and normal maps) So I downloaded the source code for the default shaders (because all I need is a normal specular bumped shader) and added "dualforward" to the parameters: Shader "Bumped Specular Dual Lightmaps" { Properties { _Color ("Main Color", Color) = (1,1,1,1) _SpecColor ("Specular Color", Color) = (0.5, 0.5, 0.5, 1) _Shininess ("Shininess", Range (0.03, 1)) = 0.078125 _MainTex ("Base (RGB) Gloss (A)", 2D) = "white" {} _BumpMap ("Normalmap", 2D) = "bump" {} } SubShader { Tags { "RenderType"="Opaque" } LOD 400 CGPROGRAM #pragma surface surf BlinnPhong dualforward sampler2D _MainTex; sampler2D _BumpMap; fixed4 _Color; half _Shininess; struct Input { float2 uv_MainTex; float2 uv_BumpMap; }; void surf (Input IN, inout SurfaceOutput o) { fixed4 tex = tex2D(_MainTex, IN.uv_MainTex); o.Albedo = tex.rgb * _Color.rgb; o.Gloss = tex.a; o.Alpha = tex.a * _Color.a; o.Specular = _Shininess; o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap)); } ENDCG } FallBack "Specular" } This, however, doesn't seem to work. When I keep the "dualforward" param, every object that uses it seems to be lit by the one directional light in the scene. When I remove the "dualforward" param, it they look like normal lightmapped objects with no normal maps or specularity. I noticed that the support for "dualforward" seems to be new in v.3.4.2, so I made sure to download it (I was running 3.4.1), but it still doesn't work. Anybody have any advice for me?

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  • Any significant performance cost to using BlendState.Premultiplied?

    - by Donutz
    Normally I guess you'd use BlendState.AlphaBlend because normally when you load your textures through the pipeline they're already premultiplied. However, if you're loading textures at runtime from PNGs or some such, you have to loop through the pixels and premultiply them, which can take a long time if you've got a lot of textures to load. So it looks (haven't tried it) like using BlendState.Premultiplied instead of BlendState.AlphaBlend should handle non-premultiplied textures and produce the same visual result, without all the startup costs. I have to wonder if there's a non-obvious cost to doing this, like a huge drop in performance or something. Anyone know?

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