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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 DX11 - multithreaded rendering?

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One would assume multithreaded rendering means the rendering is going to be done on a seperate thread from the rest of the game loop, but what exactly does this mean? I don't understand what they are offering. After all don't you have to know the positions and orientations of objects before you render them? lol. So what kind of design are they proposing and what are the advantages to be had?

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Multithread rendering for Direct3D 11 means the ability to record render commands to a list and play them back later. The multithread aspect is that the recording and the playback can happen on different threads.
The general design to make use of this is to split your whole render process in multiple subtasks. On a high level this could be a split in shadowmap, scene, ui. If you now start rendering you will dispatch these tasks to multiple threads (one per core would be best). If all tasks are done you need to playback the recorded commands in the right order.
There are two main advantages of this.

1. You need some CPU time to prepare your data to be sent to the API. This time can now be split to multiple threads. This was possible before but you had to write this record/playback framework by your own.
2. If you have a driver that natively support this new feature a huge bunch of driver work would be already done during recording. This way you free additional CPU time on the thread that is actually dispatching the recorded commands.

It’s a nice technology but you need to keep in mind that it will only pay off on systems with multiple cores. If you are trying to utilize it on a single core system you will end slower. You can work around this problem by execution the different tasks serial in the right order on single core system. In this case you need to send the commands directly to the immediate context.

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