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• ### Similar Content

• By Jiraya
For a 2D game, does using a float2 for position increases performance in any way?
I know that in the end the vertex shader will have to return a float4 anyway, but does using a float2 decreases the amount of data that will have to be sent from the CPU to the GPU?

• 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.
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.
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

# DX11 D3D11 - Pretransformed vertices? (GUI)

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I'm currently implementing a DX11 renderer for my engine.

I have regular 3d stuff going, vertex buffers, texturing, vertex and pixel shaders all forced to do my bidding. I'm a bit struggling with 2d (known as pretransformed vertices in DX9).

My goal is to provide coordinates in screen pixel values.

As I couldn't find a proper analogy I simply used an off center ortho matrix and let the vertex shader only do that one transformation. This works fine for full screen viewports.
However in my GUI code I'm using viewports heavily to clip 2d output. With my ortho matrix approach it seems that after the vertex shader there's still viewport scaling applied to the result.

What is the proper way to do pretransformed vertices, that still allow clipping, in screen space?

Here's an image explaining a bit better I hope:

[attachment=32396:viewport.png]

The top shows the "working" case, black being the screen, green the set viewport extents.
The lower part shows what I want to achieve. The top right what appears to happen (and what I don't want)

For clarification, my current "pretransforming" vertex shader looks like this:
// A constant buffer that stores the three basic column-major matrices for composing geometry.
cbuffer ModelViewProjectionConstantBuffer : register( b0 )
{
matrix model;
matrix view;
matrix projection;
matrix ortho2d;
};

// Per-vertex data used as input to the vertex shader.
{
float3 pos : POSITION;
float4 color : COLOR0;
float2 tex : TEXCOORD0;
};

// Per-pixel color data passed through the pixel shader.
{
float4 pos : SV_POSITION;
float2 tex : TEXCOORD0;
float4 color : COLOR0;
};

// Simple shader to do vertex processing on the GPU.
{

float4 pos = float4( input.pos, 1.0f );
output.pos = mul( pos, ortho2d );

// pass texture coords
output.tex = input.tex;

// Pass the color through without modification.
output.color = input.color;

return output;
}

? Edited by Endurion

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Yup, changing the viewport needs adjusted transformations, as Hodgman shows.

You could use scissors (ID3D11DeviceContext::RSSetScissorRects) for axis aligned clipping and keep the viewport as is. Probably the simplest to implement.

For completeness: There are other ways to clip:

- Look into SV_ClipDistance semantic (VS output)

- For rectangles you could "clip" in the vertex shader (rect intersection calculation, adjusting tex coords, too) (*)

- Hint: SV_Position as input to the pixel shader delivers pixel coordinates (with a 0.5 offset), this can come in handy.

Edit: (*) Can be even a good idea to do this CPU-side. Instead of lots of pipeline state changes, one can batch everything.

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Thanks both of you!

Adjusting the ortho matrix to the new viewport did the trick, thanks a lot :)

Onward I stumble towards the next problem...  generic shaders are tough to do.