Authoring an Effect

This lesson covers writing your own IEffect implementation, specifically a custom effect for rendering a skybox with a cubemap.

Setup

First create a new project using the instructions from the previous lessons: Using DeviceResources and Adding the DirectX Tool Kit which we will use for this lesson.

Writing a skybox shader

A skybox is a shape like a sphere or a cube that surrounds the render scene giving the appearance of the distant sky, horizon, and/or surroundings. In our implementation we are going to be using a cubemap (i.e. 6-faced texture) to provide the texture information on the sky. For the geometry, we'll make use of GeometricPrimitive, and the shaders we are using for the SkyboxEffect are as follows:

SkyboxEffect_Common.hlsli

cbuffer SkyboxConstants : register(b0)
{
    float4x4 WorldViewProj;
}

struct VSOutput
{
    float3 TexCoord : TEXCOORD0;
    float4 PositionPS : SV_Position;
};

SkyboxEffect_VS.hlsl

VSOutput main(float4 position : SV_Position)
{
    VSOutput vout;

    vout.PositionPS = mul(position, WorldViewProj);
    vout.PositionPS.z = vout.PositionPS.w; // Draw on far plane
    vout.TexCoord = position.xyz;

    return vout;
}

SkyboxEffect_PS.hlsl

TextureCube<float4> CubeMap : register(t0);
SamplerState Sampler        : register(s0);

float4 main(float3 texCoord : TEXCOORD0) : SV_TARGET0
{
    return CubeMap.Sample(Sampler, normalize(texCoord));
}

UNDER CONSTRUCTION

Implementing the SkyboxEffect

UNDER CONSTRUCTION

Rendering the sky

UNDER CONSTRUCTION

Next lessons: Using HDR rendering