Hi,
I have implemented shadow maps in my game, but when the sun moves, the shadows are flickering (the edges of the shadows are moving / "jumping" back and forth instead of moving slowling in one direction)...
I am still a beginner in graphics programming, so I don't know how to fix this... Do you know a good tutorial? Or do you have any hint, tip or whatever, which could help me fixing this?
This is the deferred light shader (which outputs the light intensity to a texture):
Texture2D colorTexture : register(t0);
Texture2D normalTexture : register(t1);
Texture2D positionTexture : register(t2);
Texture2D<float> pointLightTexture : register(t3);
Texture2D<float> DirectionalLightTextures[16];
static const float PI = 3.14159265f;
static const float bias = 0.0001f;
SamplerState SampleTypePoint : register(s0);
SamplerState SampleTypeClamp : register(s1);
cbuffer LightBuffer
{
matrix DirectionalLightMatrices[16];
float3 ambientColor;
uint NumDirectionalLights;
float4 diffuseColors[16];
float4 lightDirections[16];
};
cbuffer PointLightBuffer{
float4 pointLightPositions[256];
float4 pointLightColors[256]; // xyz for color, w for max light distance
uint pointLightCount;
float3 padding4;
};
struct PixelInputType
{
float4 position : SV_POSITION;
float2 tex : TEXCOORD0;
};
float4 main(PixelInputType input) : SV_TARGET
{
float4 normals;
float4 positions;
float lightIntensity;
float4 OutputColor;
float distance, distance2;
float3 distanceVector;
float4 pointLightShadow;
uint i;
float3 lightColor;
float2 DirectionalLightTexCoords;
float4 LightPosition;
float Depth, LightDepth;
normals = normalTexture.Sample(SampleTypePoint, input.tex);
positions = positionTexture.Sample(SampleTypePoint, input.tex);
OutputColor.rgb = ambientColor;
OutputColor.a = 1.0f;
if (positions.w != 0.0f){ //positions.w has been set to greater than 0.0f in other pixel shaders if this pixel doesn't belong to the sky
//////////////////////////
/// DIRECTIONAL LIGHTS ///
//////////////////////////
for (i = 0; i < NumDirectionalLights; i++){
LightPosition = mul(float4(positions.xyz, 1.0f), DirectionalLightMatrices[i]);
DirectionalLightTexCoords.x = LightPosition.x / LightPosition.w / 2.0f + 0.5f;
DirectionalLightTexCoords.y = -LightPosition.y / LightPosition.w / 2.0f + 0.5f;
if (DirectionalLightTexCoords.x >= 0.0f && DirectionalLightTexCoords.x <= 1.0f && DirectionalLightTexCoords.y >= 0.0f && DirectionalLightTexCoords.y <= 1.0f)
{
Depth = DirectionalLightTextures[i].Sample(SampleTypeClamp, DirectionalLightTexCoords);
LightDepth = LightPosition.z / LightPosition.w;
LightDepth -= bias;
if (LightDepth < Depth){
OutputColor.rgb += (diffuseColors[i].xyz * saturate(dot(normals.xyz, lightDirections[i].xyz)));
}
}
}
////////////////////
/// POINT LIGHTS ///
////////////////////
/*lightColor=float3(0.0f,0.0f,0.0f);
for(i=0;i<pointLightCount;i++){
distanceVector=positions.xyz-pointLightPositions[i].xyz;
distance2=dot(distanceVector,distanceVector);
if(distance2==0.0f){
lightColor+=pointLightColors[i].xyz;
}
else if(distance2 < pointLightColors[i].w*pointLightColors[i].w){
//TBD
}
}
if(lightColor.r != 0.0f || lightColor.g != 0.0f || lightColor.b != 0.0f){
lightColor=lightColor/max(lightColor.r,max(lightColor.g,lightColor.b));
}
*/
OutputColor.rgb=saturate(OutputColor.rgb);
}
else{
OutputColor.rgb = ambientColor;
}
return float4(OutputColor.rgb,1.0f);
}
Should I increase the texture size of the light depth texture? I already have 8192x8192 texels, but shadows are still flickering...
Should I use point or linear sampling when sampling the depth texture?
