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• By ucfchuck
I am feeding in 16 bit unsigned integer data to process in a compute shader and i need to get a standard deviation.
So I read in a series of samples and push them into float arrays
float vals1[9], vals2[9], vals3[9], vals4[9]; int x = 0,y=0; for ( x = 0; x < 3; x++) { for (y = 0; y < 3; y++) { vals1[3 * x + y] = (float) (asuint(Input1[threadID.xy + int2(x - 1, y - 1)].x)); vals2[3 * x + y] = (float) (asuint(Input2[threadID.xy + int2(x - 1, y - 1)].x)); vals3[3 * x + y] = (float) (asuint(Input3[threadID.xy + int2(x - 1, y - 1)].x)); vals4[3 * x + y] = (float) (asuint(Input4[threadID.xy + int2(x - 1, y - 1)].x)); } } I can send these values out directly and the data is as expected

Output1[threadID.xy] = (uint) (vals1[4] ); Output2[threadID.xy] = (uint) (vals2[4] ); Output3[threadID.xy] = (uint) (vals3[4] ); Output4[threadID.xy] = (uint) (vals4[4] ); however if i do anything to that data it is destroyed.
If i add a
vals1[4] = vals1[4]/2;
or a
vals1[4] = vals[1]-vals[4];
the data is gone and everything comes back 0.

How does one go about converting a uint to a float and performing operations on it and then converting back to a rounded uint?
• 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.

• 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

• 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.
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# DX11 How to render with Matrix.PerspectiveOffCenterLH

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Hi,

I am trying to render my 3d object in exact screen space coordinates with correct shading.

I tried for this orthoOffCenterLH matrix, but it produces strange render results (object in front part in disappearing and appearing during rotation). I think it because of nature of ortho projection (but maybe I am wrong).

I want to correctly display my 3d object like when I render with perspective projection.

To achieve this I tried to use PerspectiveOffCenterLH matrix, but when I apply it, I can see nothing.

Here is parameters I pass to the method:

PerspectiveOffScreenProjection = Matrix4x4F.PerspectiveOffCenterLH(0, Width, Height, 0, 100, 1);

ZFar and ZNear are flipped because I am using reversed depth buffer.

And here is how I build matrix itself

public static void PerspectiveOffCenterLH(float left, float right, float bottom, float top, float znear, float zfar, out Matrix4x4F result)
{
float zRange = zfar / (zfar - znear);

result = new Matrix4x4F();
result.M11 = 2.0f * znear / (right - left);
result.M22 = 2.0f * znear / (top - bottom);
result.M31 = (left + right) / (left - right);
result.M32 = (top + bottom) / (bottom - top);
result.M33 = zRange;
result.M34 = 1.0f;
result.M43 = -znear * zRange;
}

Also I render it without View matrix to fix object position and dont let it move somewhere.

Also if I flip Znear and ZFar back on their places, it will resnder distored like on first screenshot, but it should render like on the second screenshot

Can anyone help me to fix this issue?

Edited by BlackJoker

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Ok, seams ortho projection was enough and I just passed incorrect znear/zfar. I thought that max zfar could be 1, but obviously I was mistaken.

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