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    • By fs1
      I have been trying to see how the ID3DInclude, and how its methods Open and Close work.
      I would like to add a custom path for the D3DCompile function to search for some of my includes.
      I have not found any working example. Could someone point me on how to implement these functions? I would like D3DCompile to look at a custom C:\Folder path for some of the include files.
      Thanks
    • By stale
      I'm continuing to learn more about terrain rendering, and so far I've managed to load in a heightmap and render it as a tessellated wireframe (following Frank Luna's DX11 book). However, I'm getting some really weird behavior where a large section of the wireframe is being rendered with a yellow color, even though my pixel shader is hard coded to output white. 

      The parts of the mesh that are discolored changes as well, as pictured below (mesh is being clipped by far plane).

      Here is my pixel shader. As mentioned, I simply hard code it to output white:
      float PS(DOUT pin) : SV_Target { return float4(1.0f, 1.0f, 1.0f, 1.0f); } I'm completely lost on what could be causing this, so any help in the right direction would be greatly appreciated. If I can help by providing more information please let me know.
    • By evelyn4you
      Hello,
      i try to implement voxel cone tracing in my game engine.
      I have read many publications about this, but some crucial portions are still not clear to me.
      At first step i try to emplement the easiest "poor mans" method
      a.  my test scene "Sponza Atrium" is voxelized completetly in a static voxel grid 128^3 ( structured buffer contains albedo)
      b. i dont care about "conservative rasterization" and dont use any sparse voxel access structure
      c. every voxel does have the same color for every side ( top, bottom, front .. )
      d.  one directional light injects light to the voxels ( another stuctured buffer )
      I will try to say what i think is correct ( please correct me )
      GI lighting a given vertecie  in a ideal method
      A.  we would shoot many ( e.g. 1000 ) rays in the half hemisphere which is oriented according to the normal of that vertecie
      B.  we would take into account every occluder ( which is very much work load) and sample the color from the hit point.
      C. according to the angle between ray and the vertecie normal we would weigth ( cosin ) the color and sum up all samples and devide by the count of rays
      Voxel GI lighting
      In priciple we want to do the same thing with our voxel structure.
      Even if we would know where the correct hit points of the vertecie are we would have the task to calculate the weighted sum of many voxels.
      Saving time for weighted summing up of colors of each voxel
      To save the time for weighted summing up of colors of each voxel we build bricks or clusters.
      Every 8 neigbour voxels make a "cluster voxel" of level 1, ( this is done recursively for many levels ).
      The color of a side of a "cluster voxel" is the average of the colors of the four containing voxels sides with the same orientation.

      After having done this we can sample the far away parts just by sampling the coresponding "cluster voxel with the coresponding level" and get the summed up color.
      Actually this process is done be mip mapping a texture that contains the colors of the voxels which places the color of the neighbouring voxels also near by in the texture.
      Cone tracing, howto ??
      Here my understanding is confus ?? How is the voxel structure efficiently traced.
      I simply cannot understand how the occlusion problem is fastly solved so that we know which single voxel or "cluster voxel" of which level we have to sample.
      Supposed,  i am in a dark room that is filled with many boxes of different kind of sizes an i have a pocket lamp e.g. with a pyramid formed light cone
      - i would see some single voxels near or far
      - i would also see many different kind of boxes "clustered voxels" of different sizes which are partly occluded
      How do i make a weighted sum of this ligting area ??
      e.g. if i want to sample a "clustered voxel level 4" i have to take into account how much per cent of the area of this "clustered voxel" is occluded.
      Please be patient with me, i really try to understand but maybe i need some more explanation than others
      best regards evelyn
       
       
    • By Endemoniada

      Hi guys, when I do picking followed by ray-plane intersection the results are all wrong. I am pretty sure my ray-plane intersection is correct so I'll just show the picking part. Please take a look:
       
      // get projection_matrix DirectX::XMFLOAT4X4 mat; DirectX::XMStoreFloat4x4(&mat, projection_matrix); float2 v; v.x = (((2.0f * (float)mouse_x) / (float)screen_width) - 1.0f) / mat._11; v.y = -(((2.0f * (float)mouse_y) / (float)screen_height) - 1.0f) / mat._22; // get inverse of view_matrix DirectX::XMMATRIX inv_view = DirectX::XMMatrixInverse(nullptr, view_matrix); DirectX::XMStoreFloat4x4(&mat, inv_view); // create ray origin (camera position) float3 ray_origin; ray_origin.x = mat._41; ray_origin.y = mat._42; ray_origin.z = mat._43; // create ray direction float3 ray_dir; ray_dir.x = v.x * mat._11 + v.y * mat._21 + mat._31; ray_dir.y = v.x * mat._12 + v.y * mat._22 + mat._32; ray_dir.z = v.x * mat._13 + v.y * mat._23 + mat._33;  
      That should give me a ray origin and direction in world space but when I do the ray-plane intersection the results are all wrong.
      If I click on the bottom half of the screen ray_dir.z becomes negative (more so as I click lower). I don't understand how that can be, shouldn't it always be pointing down the z-axis ?
      I had this working in the past but I can't find my old code
      Please help. Thank you.
    • By turanszkij
      Hi,
      I finally managed to get the DX11 emulating Vulkan device working but everything is flipped vertically now because Vulkan has a different clipping space. What are the best practices out there to keep these implementation consistent? I tried using a vertically flipped viewport, and while it works on Nvidia 1050, the Vulkan debug layer is throwing error messages that this is not supported in the spec so it might not work on others. There is also the possibility to flip the clip scpace position Y coordinate before writing out with vertex shader, but that requires changing and recompiling every shader. I could also bake it into the camera projection matrices, though I want to avoid that because then I need to track down for the whole engine where I upload matrices... Any chance of an easy extension or something? If not, I will probably go with changing the vertex shaders.
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DX11 [Solved] Multi-Threading SlimDX DX11 Radeon Win7 Crash

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Hi, I write an engine for a game in C# using SlimDX (like many other developers here too ^^). One of the features is multi-threading. I do this using the deferred context of the DX11-API. Each of my threads collects the calls in its deferred context, then the deferred context is executed on this thread. Because the device is synchronized (I'm not using singlethreaded flag!), all the threads can execute their calls itself on the device. I do not need a 3rd thread, which gets the calls and puts them to the device (because this would be singlethreaded rendering!). All is working well. Now, I have a new test code for the engine, which renders parallel in 2 threads into two Win7-windows. First I created the two windows, then I created two threads, which do the DoEvents()-stuf for each window. Then on each window I created a render target. Two other rendering threads renders parallel to this two render targets. In the first few seconds, it seams that all is ok. But then the application crashes. For some reason the GUI of my Win7 gets errors too. You can see, that the window-vertices (I mean the real gui-elements in Win7) becomes crazy, or the textures becomes streched. If I create the device in SlimDX with the debug option, then the application says, there is an internal error of an external component, and that's all. On a REF device, in 90% of the tries, the GUI of Win7 becomes instable and crashes the device driver, which, after a few seconds, resets. I'm using the newest Radeon on my 5870. Has someone the problem too? Or maybe I'm wrong assuming, that I can use two threads accessing the immediate-context on the DX device simultanously (which should be synchronized internally and executed successive). [Edited by - Pyrogame on March 8, 2010 2:43:40 AM]

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You're misunderstanding how the multithreading functionality works. The point isn't to allow to have two threads using the device simultaneously, the point is to have multiple threads building up portions of a command list so that your main rendering thread can combine the portions into one big command list that can be submitted to the GPU. You're incorrect when you say that this would be like single-threaded rendering...using a deferred context allows you to spread the overhead of building the command list over multiple threads. The final part where you combine command lists is relatively cheap.

Ultimately your deferred contexts need to be serialized into a single command list. This is because the GPU only reads one command at a time, so you need to make sure that the command lists from your deferred contexts are combined in the order needed for the GPU to properly draw your scene.

If you want to support multiple output windows, you need to do it the old-fashioned way: create a swap chain for each window, render each view seperately, and present with the corresponding swap chain.

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Thank you for you comment MJP. I figured it out (with your help), why my way didn't work.

In my opinion, the deferred contexts are only simple software lists. So it shouldn't matter, how the lists are pushed to the immediate contexts. If you use a 3rd thread, you automatically serializes the lists. And this was my problem: the synchronized executing of the command lists. Because I render all my stuff in renderings threads, it doesn't matter, that this threads waits for the (synchronized) immediate context to push their commands. In my opinion, this is faster, than using a 3rd thread.

Now, instead of using a 3rd thread, I simply synchronize my immediate context like this:

for every rendering thread:
render to deferred context
build the command list
lock (immediateContext) {
immediateContext.ExecuteCommandList(commandList, false);
}
dispose the command list


Only the immediate contexts has to be synchronized. Other things, like the device itself are already synchronized by SlimDX or DX. And this was something, I misunderstud in the DX-API :) Now, all the threads render, render, render, and if one of them becomes ready, it renders to the device. Only, if two threads finishes the work simultanously, one of them has to wait for the other to execute the command list. This should be more efficient than using a third thread, which implies synchronized passing of command list from the rendering threads to this 3rd thread, etc.

Thank you for your help :)

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