So here is the premise:
I have 2 vertex buffers buffers whose data and the corresponding definition are as follows:
Vertex 1: this contains the data per instance
// Somewhere defined in the header
std::vector instancedMeshTransformMatrixArray;
...// Following code is in a function called loading data
// We will compute and setup the buffer with the information of the indexed mesh here
static float angle = 0.0f;
//angle += 90.0f * deltaTime;
XMVECTOR rotationAxis = XMVectorSet(0, 1, 1, 0);
g_WorldMatrix = XMMatrixIdentity();
XMMATRIX scale = XMMatrixScaling(1.0f, 1.0f, 1.0f);
XMMATRIX rotate = XMMatrixRotationAxis(rotationAxis, XMConvertToRadians(angle));
XMMATRIX translate = XMMatrixTranslation(0.8, 0.0f, 0.0f);
g_WorldMatrix *= translate * rotate * scale;
// We will also fill/process the matrix buffer here that will be used to index into to rendered indexed mesh
instancedMeshTransformMatrixArray.push_back(g_WorldMatrix);
// create and initialize the instanced data buffer
D3D11_BUFFER_DESC vertexInstancedBufferDesc = {};
vertexInstancedBufferDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
vertexInstancedBufferDesc.ByteWidth = sizeof(XMMATRIX) * instancedMeshTransformMatrixArray.size();
vertexInstancedBufferDesc.CPUAccessFlags = 0;
vertexInstancedBufferDesc.Usage = D3D11_USAGE_DEFAULT;
D3D11_SUBRESOURCE_DATA resourceData = {};
//ZeroMemory(&resourceData, sizeof(D3D11_SUBRESOURCE_DATA));
resourceData.pSysMem = &instancedMeshTransformMatrixArray(0);
HRESULT hr = g_d3dDevice->CreateBuffer(&vertexInstancedBufferDesc, &resourceData, &g_d3dIndexedVertexBuffer);
if (FAILED(hr))
{
return false;
}
Vertex 2: contains data by model
// Somewhere in the header
// Vertex data for a colored cube.
struct VertexPosColor
{
XMFLOAT3 Position;
XMFLOAT3 Color;
};
VertexPosColor g_Vertices(8) =
{
{ XMFLOAT3(-0.5f, -0.5f, -0.5f), XMFLOAT3(0.0f, 0.0f, 0.0f) }, // 0
{ XMFLOAT3(-0.5f, 0.5f, -0.5f), XMFLOAT3(0.0f, 1.0f, 0.0f) }, // 1
{ XMFLOAT3(0.5f, 0.5f, -0.5f), XMFLOAT3(1.0f, 1.0f, 0.0f) }, // 2
{ XMFLOAT3(0.5f, -0.5f, -0.5f), XMFLOAT3(1.0f, 0.0f, 0.0f) }, // 3
{ XMFLOAT3(-0.5f, -0.5f, 0.5f), XMFLOAT3(0.0f, 0.0f, 1.0f) }, // 4
{ XMFLOAT3(-0.5f, 0.5f, 0.5f), XMFLOAT3(0.0f, 1.0f, 1.0f) }, // 5
{ XMFLOAT3(0.5f, 0.5f, 0.5f), XMFLOAT3(1.0f, 1.0f, 1.0f) }, // 6
{ XMFLOAT3(0.5f, -0.5f, 0.5f), XMFLOAT3(1.0f, 0.0f, 1.0f) } // 7
};
...//Following code is in a function called loading data
//It is followed by the loading of data for Vertex 1
// Create and initialize the vertex buffer.
D3D11_BUFFER_DESC vertexBufferDesc = {};
//ZeroMemory(&vertexBufferDesc, sizeof(D3D11_BUFFER_DESC));
vertexBufferDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
vertexBufferDesc.ByteWidth = sizeof(VertexPosColor) * _countof(g_Vertices);
vertexBufferDesc.CPUAccessFlags = 0;
vertexBufferDesc.Usage = D3D11_USAGE_DEFAULT;
resourceData.pSysMem = g_Vertices;
hr = g_d3dDevice->CreateBuffer(&vertexBufferDesc, &resourceData, &g_d3dVertexBuffer);
if (FAILED(hr))
{
return false;
}
I'm also loading data for the index buffer and the constant buffer. I tested it with the VS Graphics debugger and the data seems to be loaded correctly. However, I can also explain to you how I do it if necessary.
Here is how to create the entry descent for the 2 buffers:
// Create the input layout for the vertex shader.
D3D11_INPUT_ELEMENT_DESC vertexLayoutDesc() = {
// Per vertex data
{ "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, offsetof(VertexPosColor,Position), D3D11_INPUT_PER_VERTEX_DATA, 0 },
{ "COLOR", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, offsetof(VertexPosColor,Color), D3D11_INPUT_PER_VERTEX_DATA, 0 },
// Instanced Data
{ "INSTANCED_MATS", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 1, 0, D3D11_INPUT_PER_INSTANCE_DATA, 1},
{ "INSTANCED_MATS", 1, DXGI_FORMAT_R32G32B32A32_FLOAT, 1, 16, D3D11_INPUT_PER_INSTANCE_DATA, 1},
{ "INSTANCED_MATS", 2, DXGI_FORMAT_R32G32B32A32_FLOAT, 1, 32, D3D11_INPUT_PER_INSTANCE_DATA, 1},
{ "INSTANCED_MATS", 3, DXGI_FORMAT_R32G32B32A32_FLOAT, 1, 64, D3D11_INPUT_PER_INSTANCE_DATA, 1}
};
hr = g_d3dDevice->CreateInputLayout(vertexLayoutDesc, _countof(vertexLayoutDesc), vertexShaderBlob->GetBufferPointer(), vertexShaderBlob->GetBufferSize(), &g_d3dInputLayout);
if (FAILED(hr)) {
return false;
}
Finally, in another function called Draw, I attach the data to the AI and call DrawInstanced as follows. :
...
const UINT vertexStride = sizeof(VertexPosColor);
const UINT offset = 0;
const UINT instancedVetexStride = sizeof(XMMATRIX);
g_d3dDeviceContext->IASetVertexBuffers(0, 1, &g_d3dVertexBuffer, &vertexStride, &offset);
g_d3dDeviceContext->IASetVertexBuffers(1, 1, &g_d3dIndexedVertexBuffer, &instancedVetexStride, &offset);
g_d3dDeviceContext->IASetInputLayout(g_d3dInputLayout);
...
// Draw the cube
g_d3dDeviceContext->DrawIndexed(std::size(g_Indicies), 0, 0);
//g_d3dDeviceContext->DrawIndexedInstanced(std::size(g_Indicies), 1, 0, 0, 0);
The following is my vertex shader as is:
//VERTEX SHADER
cbuffer PerApplication : register(b0)
{
matrix projectionMatrix;
}
cbuffer PerFrame : register(b1)
{
matrix viewMatrix;
}
cbuffer PerObject : register(b2)
{
matrix worldMatrix;
}
struct AppData
{
float3 position : POSITION;
float3 color: COLOR;
matrix instancedMatrix : INSTANCED_MATS;
};
struct VertexShaderOutput
{
float4 color : COLOR;
float4 position : SV_POSITION;
};
VertexShaderOutput SimpleVertexShader(AppData IN, uint instanceID : SV_InstanceID)
{
VertexShaderOutput OUT;
uint p = instanceID;
matrix mvp = mul(projectionMatrix, mul(viewMatrix, IN.instancedMatrix));// worldMatrix));
float4 pos = float4(IN.position, 1.0f);
OUT.position = mul(mvp, pos);
OUT.color = float4(IN.color, 1.0f);
return OUT;
}
I am not sure if I am adjusting the offsets incorrectly or if I am not correctly connecting the locations of the VBs to the AI. Or is it something to do with my entry description for BV.
But I get the following warning D3D11, which for me is vague because I don't know what offset of 80 it is.
D3D11 WARNING: ID3D11DeviceContext::DrawIndexed: Input vertex slot 1 has stride 64 which is less than the minimum stride logically expected from the current Input Layout (80 bytes). This is OK, as hardware is perfectly capable of reading overlapping data. However the developer probably did not intend to make use of this behavior. ( EXECUTION WARNING #355: DEVICE_DRAW_VERTEX_BUFFER_STRIDE_TOO_SMALL)
D3D11 WARNING: ID3D11DeviceContext::DrawIndexed: Vertex Buffer at the input vertex slot 1 is not big enough for what the Draw*() call expects to traverse. This is OK, as reading off the end of the Buffer is defined to return 0. However the developer probably did not intend to make use of this behavior. ( EXECUTION WARNING #356: DEVICE_DRAW_VERTEX_BUFFER_TOO_SMALL)
I've been stuck here for hours. Any help, advice is greatly appreciated !!
