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• 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

• 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.

• Hello,
in my game engine i want to implement my own bone weight painting tool, so to say a virtual brush painting tool for a mesh.
I have already implemented my own "dual quaternion skinning" animation system with "morphs" (=blend shapes)  and "bone driven"  "corrective morphs" (= morph is dependent from a bending or twisting bone)
But now i have no idea which is the best method to implement a brush painting system.
Just some proposals
a.  i would build a kind of additional "vertecie structure", that can help me to find the surrounding (neighbours) vertecie indexes from a given "central vertecie" index
b.  the structure should also give information about the distance from the neighbour vertecsies to the given "central vertecie" index
c.  calculate the strength of the adding color to the "central vertecie" an the neighbour vertecies by a formula with linear or quadratic distance fall off
d.  the central vertecie would be detected as that vertecie that is hit by a orthogonal projection from my cursor (=brush) in world space an the mesh
but my problem is that there could be several  vertecies that can be hit simultaniously. e.g. i want to paint the inward side of the left leg. the right leg will also be hit.
I think the given problem is quite typical an there are standard approaches that i dont know.
Any help or tutorial are welcome
P.S. I am working with SharpDX, DirectX11

• Hi, I'm implementing a simple 3D engine based on DirectX11. I'm trying to render a skybox with a cubemap on it and to do so I'm using DDS Texture Loader from DirectXTex library. I use texassemble to generate the cubemap (texture array of 6 textures) into a DDS file that I load at runtime. I generated a cube "dome" and sample the texture using the position vector of the vertex as the sample coordinates (so far so good), but I always get the same face of the cubemap mapped on the sky. As I look around I always get the same face (and it wobbles a bit if I move the camera). My code:
//Texture.cpp:         Texture::Texture(const wchar_t *textureFilePath, const std::string &textureType) : mType(textureType)         {             //CreateDDSTextureFromFile(Game::GetInstance()->GetDevice(), Game::GetInstance()->GetDeviceContext(), textureFilePath, &mResource, &mShaderResourceView);             CreateDDSTextureFromFileEx(Game::GetInstance()->GetDevice(), Game::GetInstance()->GetDeviceContext(), textureFilePath, 0, D3D11_USAGE_DEFAULT, D3D11_BIND_SHADER_RESOURCE, 0, D3D11_RESOURCE_MISC_TEXTURECUBE, false, &mResource, &mShaderResourceView);         }     // SkyBox.cpp:          void SkyBox::Draw()     {         // set cube map         ID3D11ShaderResourceView *resource = mTexture.GetResource();         Game::GetInstance()->GetDeviceContext()->PSSetShaderResources(0, 1, &resource);              // set primitive topology         Game::GetInstance()->GetDeviceContext()->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);              mMesh.Bind();         mMesh.Draw();     }     // Vertex Shader:     cbuffer Transform : register(b0)     {         float4x4 viewProjectionMatrix;     };          float4 main(inout float3 pos : POSITION) : SV_POSITION     {         return mul(float4(pos, 1.0f), viewProjectionMatrix);     }     // Pixel Shader:     SamplerState cubeSampler;     TextureCube cubeMap;          float4 main(in float3 pos : POSITION) : SV_TARGET     {         float4 color = cubeMap.Sample(cubeSampler, pos.xyz);         return color;     } I tried both functions grom DDS loader but I keep getting the same result. All results I found on the web are about the old SDK toolkits, but I'm using the new DirectXTex lib.
• By B. /
Hi Guys,
i want to draw shadows of a direction light but the shadows always disappear, if i translate my mesh (cube) in the world to far of the bounds of my orthographic projection matrix.
That my code (Based of an XNA sample i recode for my project):
// Matrix with that will rotate in points the direction of the light Matrix lightRotation = Matrix.LookAtLH(Vector3.Zero, lightDir, Vector3.Up); BoundingFrustum cameraFrustum = new BoundingFrustum(Matrix.Identity); // Get the corners of the frustum Vector3[] frustumCorners = cameraFrustum.GetCorners(); // Transform the positions of the corners into the direction of the light for (int i = 0; i < frustumCorners.Length; i++) frustumCorners[i] = Vector4F.ToVector3(Vector3.Transform(frustumCorners[i], lightRotation)); // Find the smallest box around the points BoundingBox lightBox = BoundingBox.FromPoints(frustumCorners); Vector3 boxSize = lightBox.Maximum - lightBox.Minimum; Vector3 halfBoxSize = boxSize * 0.5f; // The position of the light should be in the center of the back pannel of the box. Vector3 lightPosition = lightBox.Minimum + halfBoxSize; lightPosition.Z = lightBox.Minimum.Z; // We need the position back in world coordinates so we transform // the light position by the inverse of the lights rotation lightPosition = Vector4F.ToVector3(Vector3.Transform(lightPosition, Matrix.Invert(lightRotation))); // Create the view matrix for the light this.view = Matrix.LookAtLH(lightPosition, lightPosition + lightDir, Vector3.Up); // Create the projection matrix for the light // The projection is orthographic since we are using a directional light int amount = 25; this.projection = Matrix.OrthoOffCenterLH(boxSize.X - amount, boxSize.X + amount, boxSize.Y + amount, boxSize.Y - amount, -boxSize.Z - amount, boxSize.Z + amount); I believe the bug is by cameraFrustum to set a Matrix Idetity. I also tried with a Translation Matrix of my Camera Position and also the View Matrix of my Camera, but without success
Can anyone tell me, how to draw shadows of my direction light always where my camera is current in my scene?
Greets
Benjamin

# DX11 [SlimDX] DX11 Instancing

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Just switched from DX9 to DX11 and am attempting to instance a triangle.  Created a vertex buffer and a buffer for the instance positions.  Not sure what it is I'm doing incorrectly.

Input Layout:

            var bytecode = ShaderBytecode.CompileFromFile("Instance.fx", "fx_5_0", ShaderFlags.None, EffectFlags.None, null, includeFX);
var effect = new Effect(device, bytecode);
var technique = effect.GetTechniqueByIndex(0);
var pass = technique.GetPassByIndex(0);

layout = new InputLayout(device, pass.Description.Signature, new[] {
new InputElement("POSITION", 0, Format.R32G32B32A32_Float, 0, 0, InputClassification.PerVertexData, 0),
new InputElement("COLOR", 0, Format.R32G32B32A32_Float, 16, 0, InputClassification.PerVertexData, 0),
new InputElement("TEXCOORD", 0, Format.R32G32B32A32_Float, 0, 1, InputClassification.PerInstanceData, 1)
});

Vertex Buffer:

            var stream = new DataStream(3 * 8 * 4, true, true);
stream.Write(new Vector4( 0.2f,  0.0f,  0.0f,  1.0f));
stream.Write(new Vector4( 0.0f,  1.0f,  0.0f,  1.0f));

stream.Write(new Vector4(-0.2f,  0.0f,  0.0f,  1.0f));
stream.Write(new Vector4( 0.0f,  1.0f,  0.0f,  1.0f));

stream.Write(new Vector4( 0.0f,  2.0f,  0.0f,  1.0f));
stream.Write(new Vector4( 0.0f,  1.0f,  0.0f,  1.0f));

stream.Position = 0;

vertices = new SlimDX.Direct3D11.Buffer(device, stream, new BufferDescription()
{
BindFlags = BindFlags.VertexBuffer,
CpuAccessFlags = CpuAccessFlags.None,
OptionFlags = ResourceOptionFlags.None,
SizeInBytes = 3 * 8 * 4,
Usage = ResourceUsage.Default
});

stream.Dispose();

Instanced Positions Buffer:

            SlimDX.Direct3D11.Buffer ipos;

var stream2 = new DataStream(4 * 4 * 4, true, true);

stream2.Write(new Vector4(0, 0, 0, 1));
stream2.Write(new Vector4(2, 2, 50, 1));
stream2.Write(new Vector4(3, 5, 20, 1));
stream2.Write(new Vector4(4, 0, 3, 1));

stream2.Position = 0;

ipos = new SlimDX.Direct3D11.Buffer(device, stream2, new BufferDescription()
{
BindFlags = BindFlags.VertexBuffer,
CpuAccessFlags = CpuAccessFlags.None,
OptionFlags = ResourceOptionFlags.None,
SizeInBytes = 4 * 4 * 4,
Usage = ResourceUsage.Default
});

stream2.Dispose();

Draw Code:

                effect.GetVariableByName("World").AsMatrix().SetMatrix(World);
effect.GetVariableByName("View").AsMatrix().SetMatrix(View);
effect.GetVariableByName("Projection").AsMatrix().SetMatrix(Projection);

device.ImmediateContext.InputAssembler.InputLayout = layout;
device.ImmediateContext.InputAssembler.PrimitiveTopology = PrimitiveTopology.TriangleList;

device.ImmediateContext.InputAssembler.SetVertexBuffers(0, new VertexBufferBinding(vertices, 8 * 4, 0));
device.ImmediateContext.InputAssembler.SetVertexBuffers(1, new VertexBufferBinding(ipos, 4 * 4, 0));

pass.Apply(device.ImmediateContext);
device.ImmediateContext.DrawInstanced(3, 4, 0, 0);

float4x4 World;
float4x4 View;
float4x4 Projection;

struct VS_INPUT
{
float4 position : POSITION;
float4 xColor : COLOR0;
//float2 UV: TEXCOORD0;
float4 iposition : TEXCOORD0;
};

struct PS_INPUT
{
float4 Position : POSITION;
float4 xColor : COLOR0;
};

{
PS_INPUT output;
output.Position = (input.position) + input.iposition;
float4 worldPosition = mul(output.Position, World);
float4 viewPosition = mul(worldPosition, View);
output.Position = mul(viewPosition, Projection);
output.xColor = input.xColor;
output.xColor.a = 1;
return output;
}

float4 PS_Shader( PS_INPUT input ) : SV_Target
{
return input.xColor;
}

technique11 Render
{
pass P0
{
}
}

When the code is run, nothing is drawn.  Any help is appreciated.

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I haven't tried out your code because of the lack of a working dev machine nearby, but I can sense that there is a problem with the way you are using instancing.

Basically, break down the problem into parts and debug each. But if you're short on time then go right ahead and check your instance buffer. Hope that helps.

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D3D11: ERROR: ID3D11DeviceContext::DrawInstanced: Rasterization Unit is enabled (PixelShader is not NULL or Depth/Stencil test is enabled and RasterizedStream is not D3D11_SO_NO_RASTERIZED_STREAM) but position is not provided by the last shader before the Rasterization Unit. [ EXECUTION ERROR #362: DEVICE_DRAW_POSITION_NOT_PRESENT ]
Meaning, you need SV_POSITION at your rasterizer stage:
struct PS_INPUT
{
float4 Position : SV_POSITION;
float4 xColor : COLOR0;
};

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Oh, stupid mistake. Thanks

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D3D11: ERROR: ID3D11DeviceContext::DrawInstanced: Rasterization Unit is enabled (PixelShader is not NULL or Depth/Stencil test is enabled and RasterizedStream is not D3D11_SO_NO_RASTERIZED_STREAM) but position is not provided by the last shader before the Rasterization Unit. [ EXECUTION ERROR #362: DEVICE_DRAW_POSITION_NOT_PRESENT ]
Meaning, you need SV_POSITION at your rasterizer stage:
struct PS_INPUT
{
float4 Position : SV_POSITION;
float4 xColor : COLOR0;
};

How did you get that output? All I ever get are totally generic E_FAIL or E_INVALIDARG errors with no clue in the output as to what's wrong..

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Unbird, I too am curious how you managed to actually get useful error messages out of DirectX.

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So let me redeem you from your pain

Create your D3D11 device with D3D11_CREATE_DEVICE_DEBUG, for SlimDX it's DeviceCreationFlags.Debug.

These messages will then turn up in the debug output log of Visual Studio. For managed languages one needs to enable native code debugging ( see here). Alternatively (I use VS 2010 Express version, so that's what I have to do) one can grab debug messages globally using DebugView.