Ok, I believe that I am using the right blend state, and I believe that my ProjectionView matrix is ok, and I've eliminated relevant DX11 warnings and errors, but I still can't get anything to appear on screen. I'm greatly hampered by the fact that there is no way to debug my tessellation shaders with SharpDX and VS2012 express. This is my first stab at tessellation so I probably am doing something obviously wrong, so I would like to post my shaders to see if anything jumps out at anyone. What I am trying to do is draw instanced 3rd order bezier triangles. Besides the above, what other things might I check when nothing is drawn?

Here is the VS:

cbuffer PerFrameBuffer : register(b0)
{
	//float4x4 World; This is just the identity matrix, so not needed
	float4x4 ViewProjection;
	float4 vecEye; 
	float4 LightDirection;
	float4 LightColor; 
};

struct VertexInput
{
	//imediate data
	float3 PositionLocal		: POSITION0;
	int index					: BLENDINDICES;
	//instance data
	float3 Translation			: POSITION1;
	float Altitudes[4]			: PSIZE;
};

struct VertexOutput
{
	float3 PositionWorld	: POSITION;
	float2 MainTexCoord		: TEXCOORD;
};

VertexOutput VS(VertexInput vin)
{
	VertexOutput vout;

	//Add altitudes
	float3 transPos = vin.PositionLocal + vin.Translation;
	transPos.y += vin.Altitudes[vin.index];

	vout.MainTexCoord = transPos.xz;
	vout.PositionWorld = transPos;

	return vout;
}

Here is the pass thru Hull shader:

struct VertexOutput
{
	float3 PositionWorld	: POSITION;
	float2 MainTexCoord		: TEXCOORD;
};

struct PatchTess
{
	float EdgeTess[3]	: SV_TessFactor;
	float InsideTess	: SV_InsideTessFactor;
};

PatchTess PatchHS(InputPatch<VertexOutput,10> patch, uint patchID : SV_PrimitiveID)
{
	PatchTess pt;

	pt.EdgeTess[0] = 6;
	pt.EdgeTess[1] = 6;
	pt.EdgeTess[2] = 6;
	pt.InsideTess = 6;

	return pt;
}

struct HullOut
{
	float3 PositionWorld	: POSITION;
	float2 MainTexCoord		: TEXCOORD;
};

[domain("tri")]
[partitioning("fractional_even")]
[outputtopology("triangle_cw")]
[outputcontrolpoints(10)]
[patchconstantfunc("PatchHS")]
HullOut HS(InputPatch<VertexOutput,10> p, uint i : SV_OutputControlPointID, uint patchId : SV_PrimitiveID)
{
	HullOut hout;

	hout = p;

	return hout;
}

Here is the domain shader, where the meat of the intended operation is. The math here might be wrong, but should still produce visible geometry:

#define p300 0
#define p030 1
#define p003 2
#define p210 3
#define p201 4
#define p120 5
#define p021 6
#define p012 7
#define p102 8
#define p111 9

#define U bary.x
#define V bary.y
#define W bary.z

cbuffer PerFrameBuffer : register(b0)
{
	//float4x4 World; This is just the identity matrix, so not needed
	float4x4 ViewProjection;
	float4 vecEye; 
	float4 LightDirection;
	float4 LightColor; 
};

struct PatchTess
{
	float EdgeTess[3]	: SV_TessFactor;
	float InsideTess	: SV_InsideTessFactor;
};

struct HullOut
{
	float3 PositionWorld	: POSITION;
	float2 MainTexCoord		: TEXCOORD;
};

struct DomainOut
{
	float4 PositionH		: SV_Position;
	float3 Normal			: NORMAL0;
	float3 Tangent			: TANGENT0;
	float3 Bitangent		: BITANGENT0;
	float3 View				: NORMAL1;
	float2 MainTexCoord		: TEXCOORD0;
};

[domain("tri")]
DomainOut DS(PatchTess patchTess, float3 bary : SV_DomainLocation, const OutputPatch<HullOut,10> cp)
{
	DomainOut dout;

	float3 position =
		cp[p300].PositionWorld * pow(U,3) +
		cp[p030].PositionWorld * pow(V,3) +
		cp[p003].PositionWorld * pow(W,3) +
		cp[p210].PositionWorld * 3 * pow(U,2) * V +
		cp[p201].PositionWorld * 3 * pow(U,2) * W +
		cp[p120].PositionWorld * 3 * U * pow(V,2) +
		cp[p021].PositionWorld * 3 * pow(V,2) * W +
		cp[p012].PositionWorld * 3 * V * pow(W,2) +
		cp[p102].PositionWorld * 3 * U * pow(W,2) +
		cp[p111].PositionWorld * 6 * U * V * W;

	float3 tangent =
		cp[p300].PositionWorld * pow(U,2) +
		cp[p120].PositionWorld * pow(V,2) +
		cp[p102].PositionWorld * pow(W,2) +
		cp[p201].PositionWorld * 2 * U * W +
		cp[p210].PositionWorld * 2 * U * V +
		cp[p111].PositionWorld * 2 * V * W;

	float3 bitangent = 
		cp[p030].PositionWorld * pow(V,2) +
		cp[p012].PositionWorld * pow(W,2) +
		cp[p210].PositionWorld * pow(U,2) +
		cp[p120].PositionWorld * 2 * U * V +
		cp[p021].PositionWorld * 2 * V * W +
		cp[p111].PositionWorld * 2 * U * W;

	tangent = normalize(tangent);
	bitangent = normalize(bitangent);
	float3 normal = normalize(cross(tangent,bitangent));

	dout.View = vecEye.xyz - position.xyz;
	dout.PositionH = mul(float4(position,1.0f),ViewProjection);
	dout.Normal = normal;
	dout.Tangent = tangent;
	dout.Bitangent = bitangent;

	dout.MainTexCoord = cp[p300].MainTexCoord * U + cp[p030].MainTexCoord * V + cp[p003].MainTexCoord * W;

	return dout;
}

Last is the pixel shader, which has a simple shading algorithm that has been disabled to merely produce one color. I'm really hoping to see that color 'Reddish' but it's not happening:

cbuffer PerFrameBuffer : register(b0)
{
	//float4x4 World; This is just the identity matrix, so not needed
	float4x4 ViewProjection;
	float4 vecEye; 
	float4 LightDirection;
	float4 LightColor; 
};

struct DomainOut
{
	float4 PositionH		: SV_Position;
	float3 Normal			: NORMAL0;
	float3 Tangent			: TANGENT0;
	float3 Bitangent		: BITANGENT0;
	float3 View				: NORMAL1;
	float2 MainTexCoord		: TEXCOORD0;
};

float4 PS(DomainOut input) : SV_Target
{
    float4 Color = float4 (0, 0, 0, 1); 
	float4 Reddish = float4 (0.8,0.5,0.8,1.0);
	float4 specularColor = float4(1,1,1,1);

    float4 diffuse = {LightColor.rgb, 1.0f};   
    float4 ambient = { 0.03f, 0.03f, 0.03f, 1.0f};   
  
    float3 LightDir = normalize(LightDirection.xyz);   
    float3 ViewDir = normalize(input.View);    
       
    float4 diff = saturate(dot(input.Normal, LightDir)); // diffuse component   
  
    // R = 2 * (N.L) * N - L   
    float3 Reflect = normalize(2 * diff * input.Normal - LightDir);    
    float specular = pow(saturate(dot(Reflect, ViewDir)), 15); // R.V^n   
  
    // I = Acolor + Dcolor * N.L + (R.V)n   
    Color += ambient + diffuse  * diff + specular * (specularColor * LightColor);  

	float4 Final = Color * Reddish;
	Final.a = 1.0;

	//return Final;
	return Reddish;
       
}

Thanks Jason. That sounds like a good idea. It's time to start paring things down. One thing I forgot to mention above was the setup of the depth buffer, as if maybe it was always failing the depth test or something, I've got that set up how it should be, I had forgotten to set the DepthStencilState, but fixing that didn't help. I'll do what you suggest, although I'll have to change alot of stuff, because my inputs are just a series of control points. I'll have to decide how to turn them into triangles, or just draw points.

As this is my first dx11 app, I do have a related question. Is there anything else I am supposed to do to turn on the different pipeline stages other than setting them in the immediate context? In SharpDX you would say context.HullShader.Set(hexCornerHS).

For instance let's say I want to use tessellation on one drawn element, and then only a vertex/pixel shader on another drawn element. Would I then have to set the hull/domain shaders to 'null' in order to disable them?

[maxvertexcount(3)]
void PassThroughTriangleGS(triangle DomainOut gin[3], inout TriangleStream<DomainOut> stream)
{
    for(int i = 0; i < 3; i++)
    {
        stream.Append(gin);
    }
    stream.RestartStrip();
}

interesting tip unbird. I thought that I couldn't have a geometry shader when the tessellation stages were active.

Ok, I tried unbird's trick, and kindof unfortunately I got almost the exact geometry I expected in the post GS window. However, I don't understand why the viewport shows a mere dot. In actual rendering, I don't see a dot even though my pixel shader currently puts out one color.

[attachment=14875:PIXpic.png]

To see how this geometry looks right to me, here is a screenshot of the DirectX 9 version of this project: It's basically a hex terrain map.

[attachment=14876:HexMap.jpg]