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Back to Graphics and GPU Programming

Problem with Diffuse Lighting

Started by
4 comments, last by teletubby329 7 years, 7 months ago

So I am currently implementing Diffuse & Ambient Lighting based off this tutorial: https://www.braynzarsoft.net/viewtutorial/q16390-simple-lighting

I think I have implemented everything correctly, so the Ambient & Diffuse Light should work correctly with the directional light but I just get Ambient Light. Can someone help me fix this? Here is my code.


MAIN.CPP

#include "Header.h"

// the WindowProc function prototype
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);


// the entry point for any Windows program
int WINAPI WinMain(HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine,
    int nCmdShow)
{
    HWND hWnd;
    WNDCLASSEX wc;

    ZeroMemory(&wc, sizeof(WNDCLASSEX));

    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
    wc.lpszClassName = L"WindowClass";

    RegisterClassEx(&wc);

    RECT wr = { 0, 0, 800, 600 };
    AdjustWindowRect(&wr, WS_OVERLAPPEDWINDOW, FALSE);

    hWnd = CreateWindowEx(NULL,
        L"WindowClass",
        L"Eagle Engine (Alpha)",
        WS_OVERLAPPEDWINDOW,
        SCREEN_WIDTH,
        SCREEN_HEIGHT,
        wr.right - wr.left,
        wr.bottom - wr.top,
        NULL,
        NULL,
        hInstance,
        NULL);

    ShowWindow(hWnd, nCmdShow);

    // set up and initialize Direct3D
    InitD3D(hWnd);

    // enter the main loop:

    MSG msg;

    while (TRUE)
    {
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);

            if (msg.message == WM_QUIT)
                break;
        }

        RenderFrame();
    }

    // clean up DirectX and COM
    CleanD3D();

    return msg.wParam;
}


// this is the main message handler for the program
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_DESTROY:
    {
        PostQuitMessage(0);
        return 0;
    } break;
    }

    return DefWindowProc(hWnd, message, wParam, lParam);
}

cbPerObject cbPerObj;

// this function initializes and prepares Direct3D for use
void InitD3D(HWND hWnd)
{
    // create a struct to hold information about the swap chain
    DXGI_SWAP_CHAIN_DESC scd;

    // clear out the struct for use
    ZeroMemory(&scd, sizeof(DXGI_SWAP_CHAIN_DESC));

    HRESULT hr = S_OK;

    // fill the swap chain description struct
    scd.BufferCount = 2;                                    // one back buffer
    scd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;     // use 32-bit color
    scd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;      // how swap chain is to be used
    scd.OutputWindow = hWnd;                                // the window to be used
    scd.SampleDesc.Count = 8;                               // how many multisamples
    scd.SampleDesc.Quality = 1;
    scd.Windowed = TRUE;
    scd.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;     // allow full-screen switching// windowed/full-screen mode
                                                            // create a device, device context and swap chain using the information in the scd struct

    hr = D3D11CreateDeviceAndSwapChain(NULL,
        D3D_DRIVER_TYPE_HARDWARE,
        NULL,
        NULL,
        NULL,
        NULL,
        D3D11_SDK_VERSION,
        &scd,
        &swapchain,
        &dev,
        NULL,
        &devcon);

    // get the address of the back buffer
    ID3D11Texture2D *pBackBuffer;
    swapchain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&pBackBuffer);

    // use the back buffer address to create the render target
    dev->CreateRenderTargetView(pBackBuffer, NULL, &backbuffer);
    pBackBuffer->Release();

    // set the render target as the back buffer
    devcon->OMSetRenderTargets(1, &backbuffer, NULL);

    ID3D11Texture2D* pDepthStencil = NULL;
    D3D11_TEXTURE2D_DESC descDepth;
    descDepth.Width = SCREEN_WIDTH;
    descDepth.Height = SCREEN_HEIGHT;
    descDepth.MipLevels = 1;
    descDepth.ArraySize = 1;
    descDepth.Format = DXGI_FORMAT_R32_TYPELESS;
    descDepth.SampleDesc.Count = scd.SampleDesc.Count;
    descDepth.SampleDesc.Quality = scd.SampleDesc.Quality;
    descDepth.Usage = D3D11_USAGE_DEFAULT;
    descDepth.BindFlags = D3D11_BIND_DEPTH_STENCIL | D3D11_BIND_SHADER_RESOURCE;
    descDepth.CPUAccessFlags = 0;
    descDepth.MiscFlags = 0;
    hr = dev->CreateTexture2D(&descDepth, NULL, &pDepthStencil);

    D3D11_DEPTH_STENCIL_VIEW_DESC descDSV;
    descDSV.Format = DXGI_FORMAT_D32_FLOAT_S8X24_UINT;
    descDSV.ViewDimension = D3D11_DSV_DIMENSION_TEXTURE2DMS;
    descDSV.Texture2D.MipSlice = 0;

    dev->CreateTexture2D(&descDepth, NULL, &pDepthStencil);

    // Create the depth stencil view
    ID3D11DepthStencilView* pDSV;
    hr = dev->CreateDepthStencilView(pDepthStencil, // Depth stencil texture
        &descDSV, // Depth stencil desc
        &pDSV);  // [out] Depth stencil view

    devcon->OMSetRenderTargets(1, &backbuffer, pDSV);


    // Set the viewport
    D3D11_VIEWPORT viewport;
    ZeroMemory(&viewport, sizeof(D3D11_VIEWPORT));

    viewport.TopLeftX = 0;
    viewport.TopLeftY = 0;
    viewport.Width = SCREEN_WIDTH;
    viewport.Height = SCREEN_HEIGHT;
    viewport.MinDepth = 0.0f;
    viewport.MaxDepth = 1.0f;

    devcon->RSSetViewports(1, &viewport);

    //Create the buffer to send to the cbuffer in effect file
    D3D11_BUFFER_DESC cbbd;
    ZeroMemory(&cbbd, sizeof(D3D11_BUFFER_DESC));

    cbbd.Usage = D3D11_USAGE_DEFAULT;
    cbbd.ByteWidth = sizeof(cbPerObject);
    cbbd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
    cbbd.CPUAccessFlags = 0;
    cbbd.MiscFlags = 0;

    dev->CreateBuffer(&cbbd, NULL, &cbPerObjectBuffer);

    ZeroMemory(&cbbd, sizeof(D3D11_BUFFER_DESC));

    cbbd.Usage = D3D11_USAGE_DEFAULT;
    cbbd.ByteWidth = sizeof(cbPerFrame);
    cbbd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
    cbbd.CPUAccessFlags = 0;
    cbbd.MiscFlags = 0;

    dev->CreateBuffer(&cbbd, NULL, &cbPerFrameBuffer);

    //Camera information
    camPosition = XMVectorSet(-5.0f, 3.0f, -5.0f, 0.0f); //Position X,Y,Z
    camTarget = XMVectorSet(0.0f, 0.0f, 0.0f, 0.0f);   //Rotation X,Y,Z
    camUp = XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f);

    //Set the View matrix
    camView = XMMatrixLookAtLH(camPosition, camTarget, camUp);

    //Set the Projection matrix
    camProjection = XMMatrixPerspectiveFovLH(0.4f*3.14f, (float)SCREEN_WIDTH/SCREEN_HEIGHT , 1.0f, 1000.0f);

    D3DX11CreateShaderResourceViewFromFile(dev, L"braynzar.jpg", NULL, NULL, &CubesTexture, NULL);

    D3D11_SAMPLER_DESC sampDesc;
    ZeroMemory(&sampDesc, sizeof(sampDesc));
    sampDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
    sampDesc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
    sampDesc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
    sampDesc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
    sampDesc.ComparisonFunc = D3D11_COMPARISON_NEVER;
    sampDesc.MinLOD = 0;
    sampDesc.MaxLOD = D3D11_FLOAT32_MAX;

    dev->CreateSamplerState(&sampDesc, &CubesTexSamplerState);
    InitScene();
    UpdateScene();
}

// this is the function used to render a single frame
void RenderFrame(void)
{
    //Clear our backbuffer
    float bgColor[4] = { (0.0f, 0.0f, 0.0f, 0.0f) };
    devcon->ClearRenderTargetView(backbuffer, bgColor);

    //Refresh the Depth/Stencil view
    devcon->ClearDepthStencilView(pDSV, D3D11_CLEAR_DEPTH | D3D11_CLEAR_STENCIL, 1.0f, 0);

    constbuffPerFrame.light = light;
    devcon->UpdateSubresource(cbPerFrameBuffer, 0, NULL, &constbuffPerFrame, 0, 0);
    devcon->PSSetConstantBuffers(0, 1, &cbPerFrameBuffer);

    ///////////////**************new**************////////////////////
    //Set the WVP matrix and send it to the constant buffer in effect file
    WVP = cube1World * camView * camProjection;
    cbPerObj.WVP = XMMatrixTranspose(WVP);
    devcon->UpdateSubresource(cbPerObjectBuffer, 0, NULL, &cbPerObj, 0, 0);
    devcon->VSSetConstantBuffers(0, 1, &cbPerObjectBuffer);
    devcon->PSSetShaderResources(0, 1, &CubesTexture);
    devcon->PSSetSamplers(0, 1, &CubesTexSamplerState);

    //Draw the first cube
    devcon->DrawIndexed(36, 0, 0);

    WVP = cube2World * camView * camProjection;
    cbPerObj.WVP = XMMatrixTranspose(WVP);
    devcon->UpdateSubresource(cbPerObjectBuffer, 0, NULL, &cbPerObj, 0, 0);
    devcon->VSSetConstantBuffers(0, 1, &cbPerObjectBuffer);
    devcon->PSSetShaderResources(0, 1, &CubesTexture);
    devcon->PSSetSamplers(0, 1, &CubesTexSamplerState);

    //Draw the second cube
    devcon->DrawIndexed(36, 0, 0);
    ///////////////**************new**************////////////////////

    //Present the backbuffer to the screen
    swapchain->Present(0, 0);
};


// this is the function that cleans up Direct3D and COM
void CleanD3D(void)
{
    swapchain->SetFullscreenState(FALSE, NULL);    // switch to windowed mode

    // close and release all existing COM objects
    swapchain->Release();
    dev->Release();
    backbuffer->Release();
    devcon->Release();
    squareIndexBuffer->Release();
    squareVertBuffer->Release();
    VS->Release();
    PS->Release();
    VS_Buffer->Release();
    PS_Buffer->Release();
    vertLayout->Release();
    cbPerObjectBuffer->Release();
    cbPerFrameBuffer->Release();
}

void InitScene()
{
    //Compile Shaders from shader file
    D3DX11CompileFromFile(L"Effects.fx", 0, 0, "VS", "vs_4_0", 0, 0, 0, &VS_Buffer, 0, 0);
    D3DX11CompileFromFile(L"Effects.fx", 0, 0, "PS", "ps_4_0", 0, 0, 0, &PS_Buffer, 0, 0);

    //Create the Shader Objects
    dev->CreateVertexShader(VS_Buffer->GetBufferPointer(), VS_Buffer->GetBufferSize(), NULL, &VS);
    dev->CreatePixelShader(PS_Buffer->GetBufferPointer(), PS_Buffer->GetBufferSize(), NULL, &PS);

    //Set Vertex and Pixel Shaders
    devcon->VSSetShader(VS, 0, 0);
    devcon->PSSetShader(PS, 0, 0);

    light.dir = XMFLOAT3(0.25f, 1.0f, 1.0f);
    light.ambient = XMFLOAT4(0.2f, 0.2f, 0.2f, 1.0f);
    light.diffuse = XMFLOAT4(1.0f, 1.0f, 2.0f, 5.0f);

    //Create the vertex buffer
    Vertex v[] =
    {
        // Front Face
        Vertex(-1.0f, -1.0f, -1.0f, 0.0f, 1.0f,-1.0f, -1.0f, -1.0f),
        Vertex(-1.0f,  1.0f, -1.0f, 0.0f, 0.0f,-1.0f,  1.0f, -1.0f),
        Vertex(1.0f,  1.0f, -1.0f, 1.0f, 0.0f, 1.0f,  1.0f, -1.0f),
        Vertex(1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, -1.0f, -1.0f),

        // Back Face
        Vertex(-1.0f, -1.0f, 1.0f, 1.0f, 1.0f,-1.0f, -1.0f, 1.0f),
        Vertex(1.0f, -1.0f, 1.0f, 0.0f, 1.0f, 1.0f, -1.0f, 1.0f),
        Vertex(1.0f,  1.0f, 1.0f, 0.0f, 0.0f, 1.0f,  1.0f, 1.0f),
        Vertex(-1.0f,  1.0f, 1.0f, 1.0f, 0.0f,-1.0f,  1.0f, 1.0f),

        // Top Face
        Vertex(-1.0f, 1.0f, -1.0f, 0.0f, 1.0f,-1.0f, 1.0f, -1.0f),
        Vertex(-1.0f, 1.0f,  1.0f, 0.0f, 0.0f,-1.0f, 1.0f,  1.0f),
        Vertex(1.0f, 1.0f,  1.0f, 1.0f, 0.0f, 1.0f, 1.0f,  1.0f),
        Vertex(1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f),

        // Bottom Face
        Vertex(-1.0f, -1.0f, -1.0f, 1.0f, 1.0f,-1.0f, -1.0f, -1.0f),
        Vertex(1.0f, -1.0f, -1.0f, 0.0f, 1.0f, 1.0f, -1.0f, -1.0f),
        Vertex(1.0f, -1.0f,  1.0f, 0.0f, 0.0f, 1.0f, -1.0f,  1.0f),
        Vertex(-1.0f, -1.0f,  1.0f, 1.0f, 0.0f,-1.0f, -1.0f,  1.0f),

        // Left Face
        Vertex(-1.0f, -1.0f,  1.0f, 0.0f, 1.0f,-1.0f, -1.0f,  1.0f),
        Vertex(-1.0f,  1.0f,  1.0f, 0.0f, 0.0f,-1.0f,  1.0f,  1.0f),
        Vertex(-1.0f,  1.0f, -1.0f, 1.0f, 0.0f,-1.0f,  1.0f, -1.0f),
        Vertex(-1.0f, -1.0f, -1.0f, 1.0f, 1.0f,-1.0f, -1.0f, -1.0f),

        // Right Face
        Vertex(1.0f, -1.0f, -1.0f, 0.0f, 1.0f, 1.0f, -1.0f, -1.0f),
        Vertex(1.0f,  1.0f, -1.0f, 0.0f, 0.0f, 1.0f,  1.0f, -1.0f),
        Vertex(1.0f,  1.0f,  1.0f, 1.0f, 0.0f, 1.0f,  1.0f,  1.0f),
        Vertex(1.0f, -1.0f,  1.0f, 1.0f, 1.0f, 1.0f, -1.0f,  1.0f),
    };

    DWORD indices[] =
    {
        // Front Face
        0,  1,  2,
        0,  2,  3,

        // Back Face
        4,  5,  6,
        4,  6,  7,

        // Top Face
        8,  9, 10,
        8, 10, 11,

        // Bottom Face
        12, 13, 14,
        12, 14, 15,

        // Left Face
        16, 17, 18,
        16, 18, 19,

        // Right Face
        20, 21, 22,
        20, 22, 23
    };

    D3D11_BUFFER_DESC indexBufferDesc;
    ZeroMemory(&indexBufferDesc, sizeof(indexBufferDesc));

    indexBufferDesc.Usage = D3D11_USAGE_DEFAULT;
    indexBufferDesc.ByteWidth = sizeof(DWORD) * 12 * 3;
    indexBufferDesc.BindFlags = D3D11_BIND_INDEX_BUFFER;
    indexBufferDesc.CPUAccessFlags = 0;
    indexBufferDesc.MiscFlags = 0;

    D3D11_SUBRESOURCE_DATA iinitData;

    iinitData.pSysMem = indices;
    dev->CreateBuffer(&indexBufferDesc, &iinitData, &squareIndexBuffer);

    devcon->IASetIndexBuffer(squareIndexBuffer, DXGI_FORMAT_R32_UINT, 0);


    D3D11_BUFFER_DESC vertexBufferDesc;
    ZeroMemory(&vertexBufferDesc, sizeof(vertexBufferDesc));

    vertexBufferDesc.Usage = D3D11_USAGE_DYNAMIC;
    vertexBufferDesc.ByteWidth = sizeof(Vertex) * 24;
    vertexBufferDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
    vertexBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
    vertexBufferDesc.MiscFlags = 0;

    D3D11_SUBRESOURCE_DATA vertexBufferData;

    ZeroMemory(&vertexBufferData, sizeof(vertexBufferData));
    vertexBufferData.pSysMem = v;
    dev->CreateBuffer(&vertexBufferDesc, &vertexBufferData, &squareVertBuffer);

    //Set the vertex buffer
    UINT stride = sizeof(Vertex);
    UINT offset = 0;
    devcon->IASetVertexBuffers(0, 1, &squareVertBuffer, &stride, &offset);

    //Create the Input Layout
    dev->CreateInputLayout(layout, numElements, VS_Buffer->GetBufferPointer(),
        VS_Buffer->GetBufferSize(), &vertLayout);

    //Set the Input Layout
    devcon->IASetInputLayout(vertLayout);

    //Set Primitive Topology
    devcon->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
}

void UpdateScene()
{
    //Reset cube1World
    cube1World = XMMatrixIdentity();

    Translation = XMMatrixTranslation(0.0f, 0.0f, 4.0f);

    //Define cube2's world space matrix
    Scale = XMMatrixScaling(1.3f, 1.3f, 1.3f);

    //Set cube1's world space using the transformations
    cube1World = Translation;

    //Reset cube2World
    cube2World = XMMatrixIdentity();

    //Set cube2's world space matrix
    cube2World = Scale;
}

effects.fx

struct Light
{
    float3 dir;
    float4 ambient;
    float4 diffuse;
};

cbuffer cbPerFrame
{
    Light light;
};

cbuffer cbPerObject
{
    float4x4 WVP;
    float4x4 World;
};

Texture2D ObjTexture;
SamplerState ObjSamplerState;

struct VS_OUTPUT
{
    float4 Pos : SV_POSITION;
    float2 TexCoord : TEXCOORD;
    float3 normal : NORMAL;
};

VS_OUTPUT VS(float4 inPos : POSITION, float2 inTexCoord : TEXCOORD, float3 normal : NORMAL)
{
    VS_OUTPUT output;

    output.Pos = mul(inPos, WVP);

    output.normal = mul(normal, World);

    output.TexCoord = inTexCoord;

    return output;
}

float4 PS(VS_OUTPUT input) : SV_TARGET
{
    input.normal = normalize(input.normal);

    float4 diffuse = ObjTexture.Sample(ObjSamplerState, input.TexCoord);

    float3 finalColor;

    finalColor = diffuse * light.ambient;
    finalColor += saturate(dot(light.dir, input.normal) * light.diffuse * diffuse);

    return float4(finalColor, diffuse.a);
}

Here's a photo of What I'm getting: http://i.stack.imgur.com/519Jz.jpg

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I don't know what the problem is but these values look a little odd, are they correct?


    light.dir = XMFLOAT3(0.25f, 1.0f, 1.0f);
    light.ambient = XMFLOAT4(0.2f, 0.2f, 0.2f, 1.0f);
    light.diffuse = XMFLOAT4(1.0f, 1.0f, 2.0f, 5.0f);

I would expect light.dir to be normalized and diffuse to have only values <= 1. This may not be true for what you are doing though (I didn't check the tutorial you are following). I would suggest cutting this down a little to it's bare-bones and trying to identify what's wrong from there. Looking at your vertices it is difficult to work out what elements are what but from your shader I guess it goes position/tex/normal; in which case your normals look very odd, even if they are position/normal/tex they still look odd. I would start with that.

If all that is correct then you could try commenting out your current fragment code and put in some very basic code instead. I would do just


float d = dot(light.dir, input.normal);
return float4(d, d, d, 1.0);

That should at least show if the normals/light dir are correct, it'll be white for surfaces directly facing the light and fade to black as faces are turned away. d will be -1 for faces looking away but that should still come out as black. Once you have confirmed those are correct you can then add in the part for material and light color again and then add ambient back in.

Interested in Fractals? Check out my App, Fractal Scout, free on the Google Play store.

You are not setting the World matrix in the object CB. The transformed normal is probably coming out as (0,0,0)

@AliasBinman, I don't understand what you mean, can you explain this with some code?

@AliasBinman, I don't understand what you mean, can you explain this with some code?

In your shader you have:


cbuffer cbPerObject
{
    float4x4 WVP;
    float4x4 World;
};

In your code you set the value of WVP but you never set the value of World so it is likely to be using a matrix full of 0s. You then multiply your normal by that:


output.normal = mul(normal, World);

which will leave your normal being (0, 0, 0) which is invalid. Dot product with that will also be 0 and so your diffuse contribution also becomes 0.

Well spotted Aliasbinman,

Interested in Fractals? Check out my App, Fractal Scout, free on the Google Play store.

Thanks everyone. Good spot Aliasbinman. I solved the problem by setting the world matrix:


cbPerObj.World = XMMatrixTranspose(cube1World);
WVP = cube1World * camView * camProjection;
cbPerObj.WVP = XMMatrixTranspose(WVP);

This topic is closed to new replies.

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