Followers 0

# DX11 DX11 Instancing question

## 5 posts in this topic

Hi everyone,

Based on this tutorial: http://www.rastertek.com/dx11tut37.html

can someone point to me some hints on how to pass the rotation of the Instances to the shader?

0

##### Share on other sites

Replace the instance position inside VertexInputType by a matrix.

You could also use an array of matrices (inside constant buffer) and index it using SV_InstanceID.

0

##### Share on other sites

you mean like that ?

struct VertexInputType
{
float4 position : POSITION;
float2 tex : TEXCOORD0;
matrix instancePosition;
};



and in what way should I modify the D3D11_INPUT_ELEMENT_DESC ?

        polygonLayout[2].SemanticName = "TEXCOORD";
polygonLayout[2].SemanticIndex = 1;
polygonLayout[2].Format = DXGI_FORMAT_R32G32B32_FLOAT;
polygonLayout[2].InputSlot = 1;
polygonLayout[2].AlignedByteOffset = 0;
polygonLayout[2].InputSlotClass = D3D11_INPUT_PER_INSTANCE_DATA;
polygonLayout[2].InstanceDataStepRate = 1;


0

##### Share on other sites

You will need multiple elements inside the InputLayout describing the matrix (incrementing the SemanticIndex and AlignedByteOffset).

The DirectX SDK (june 2010) has a sample about instancing that uses this method ( inside the Direct3D10 folder, so minor changes might be needed to adapt it to Dx11)

0

##### Share on other sites
• looks like  passing the rotation with TEXCOORD is not possible.
• using an  array of matrices (inside constant buffer) and index it using SV_InstanceID works with rotation, but it can only pass 1024 matrix meaning i can only have 1024 instances of the same model.
• looking at the DirectX SDK(Direct3D10 folder, Instancing10) i find that is doing Instancing with this  "row_major float4x4 mTransform : mTransform;" but i have idea how to use this in dx11, in order to get  Instance with rotation and in large numbers like 10k not just 1024.

any ideals?

Edited by michaelmk86
0

bump

0

## Create an account

Register a new account

Followers 0

• ### Similar Content

• Hi Guys,
I am just wondering if it is possible to acquire the address of the backbuffer if an API (based on DX11) only exposes the 'device' and 'context' pointers?
Any advice would be greatly appreciated

• bool InitDirect3D::Init() { if (!D3DApp::Init()) { return false; } //Additional Initialization //Disable Alt+Enter Fullscreen Toggle shortkey IDXGIFactory* factory; CreateDXGIFactory(__uuidof(IDXGIFactory), reinterpret_cast<void**>(&factory)); factory->MakeWindowAssociation(mhWindow, DXGI_MWA_NO_WINDOW_CHANGES); factory->Release(); return true; }
As stated on the title and displayed on the code above, regardless of it Alt+Enter still takes effect...
I recall something from the book during the swapChain creation, where in order to create it one has to use the same factory used to create the ID3D11Device, therefore I tested and indeed using that same factory indeed it work.
How is that one particular factory related to my window and how come the MakeWindowAssociation won't take effect with a newly created factory?
Also what's even the point of being able to create this Factories if they won't work,?(except from that one associated with the ID3D11Device)
• By ProfL
Can anyone recommend a wrapper for Direct3D 11 that is similarly simple to use as SFML? I don't need all the image formats etc. BUT I want a simple way to open a window, allocate a texture, buffer, shader.

• Q1:
Since there is no more fixed pipeline rendering in DX11, for every part of rendering in DX11, do I need to create a brand-new vertex shader and pixel shader... or at least I have to find one relevant online. If you work on skinned meshes and other effects originally worked in DX9 fixed pipeline, do I have to rework everything by now?

Q2:
For assimp, if it originally was designed for DX9, like it is coupled to a DX9 device for creating meshes and materials etc. Do I have to add in the DX11 device in the assimp, or can I just leave the assimp to remain in DX9 and after the meshes are loaded, I just convert the vertex buffers and index buffers into DX11 buffers?
Thanks
Jack

• This header is mentioned in the book I'm reading but there is no documentation on msdn... Is it like an... outdated and abandoned header?
If so, what's the current default/recomended library for handling errors with directX?

• 17
• 12
• 11
• 27
• 20