Hello,
I have a weird problem when porting the game from WP to Android. The water shader works correctly on Android emulator, but wrong on a real Android phone.
Example:
Correct on emulator:
Wrong on a real phone:
The behavior is quite strange - the reflections seem to look like in a kaleidoscope. Four “copies” of reflected model fold to the center of the renderstate as I approach the model.
Here is the shader code for water that I am using:
//------- Constants --------
float4x4 xView;
float4x4 xReflectionView;
float4x4 xProjection;
float4x4 xWorld;
float3 xLightDirection;
float xWaveLength;
float xWaveHeight;
float3 xCamPos;
float xTime;
float xWindForce;
float3 xWindDirection;
//------- Texture Samplers --------
Texture xReflectionMap;
sampler ReflectionSampler = sampler_state { texture = <xReflectionMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = MIRROR; AddressV = MIRROR;};
Texture xRefractionMap;
sampler RefractionSampler = sampler_state { texture = <xRefractionMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = MIRROR; AddressV = MIRROR;};
Texture xWaterBumpMap;
sampler WaterBumpMapSampler = sampler_state { texture = <xWaterBumpMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = MIRROR; AddressV = MIRROR;};
//------- Technique: Water --------
struct WVertexToPixel
{
float4 Position : POSITION;
float4 ReflectionMapSamplingPos : TEXCOORD1;
float2 BumpMapSamplingPos : TEXCOORD2;
float4 RefractionMapSamplingPos : TEXCOORD3;
float4 Position3D : TEXCOORD4;
};
struct WPixelToFrame
{
float4 Color : COLOR0;
};
WVertexToPixel WaterVS(float4 inPos : POSITION, float2 inTex: TEXCOORD)
{
WVertexToPixel Output = (WVertexToPixel)0;
float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
float4x4 preReflectionViewProjection = mul (xReflectionView, xProjection);
float4x4 preWorldReflectionViewProjection = mul (xWorld, preReflectionViewProjection);
Output.Position = mul(inPos, preWorldViewProjection);
Output.ReflectionMapSamplingPos = mul(inPos, preWorldReflectionViewProjection);
Output.RefractionMapSamplingPos = mul(inPos, preWorldViewProjection);
Output.Position3D = mul(inPos, xWorld);
float3 windDir = normalize(xWindDirection);
float3 perpDir = cross(xWindDirection, float3(0,1,0));
float ydot = dot(inTex, xWindDirection.xz);
float xdot = dot(inTex, perpDir.xz);
float2 moveVector = float2(xdot, ydot);
moveVector.y += xTime*xWindForce;
Output.BumpMapSamplingPos = moveVector/xWaveLength;
return Output;
}
WPixelToFrame WaterPS(WVertexToPixel PSIn) : SV_TARGET0
{
WPixelToFrame Output = (WPixelToFrame)0;
float4 bumpColor = tex2D(WaterBumpMapSampler, PSIn.BumpMapSamplingPos);
float2 perturbation = xWaveHeight*(bumpColor.rg - 0.5f)*2.0f;
float2 ProjectedTexCoords;
ProjectedTexCoords.x = PSIn.ReflectionMapSamplingPos.x/PSIn.ReflectionMapSamplingPos.w/2.0f + 0.5f;
ProjectedTexCoords.y = -PSIn.ReflectionMapSamplingPos.y/PSIn.ReflectionMapSamplingPos.w/2.0f + 0.5f;
float2 perturbatedTexCoords = ProjectedTexCoords + perturbation;
float4 reflectiveColor = tex2D(ReflectionSampler, perturbatedTexCoords);
float2 ProjectedRefrTexCoords;
ProjectedRefrTexCoords.x = PSIn.RefractionMapSamplingPos.x/PSIn.RefractionMapSamplingPos.w/2.0f + 0.5f;
ProjectedRefrTexCoords.y = -PSIn.RefractionMapSamplingPos.y/PSIn.RefractionMapSamplingPos.w/2.0f + 0.5f;
float2 perturbatedRefrTexCoords = ProjectedRefrTexCoords + perturbation;
float4 refractiveColor = tex2D(RefractionSampler, perturbatedRefrTexCoords);
float3 eyeVector = normalize(xCamPos - PSIn.Position3D);
float3 normalVector = (bumpColor.rbg-0.5f)*2.0f;
float fresnelTerm = dot(eyeVector, normalVector);
float4 combinedColor = lerp(reflectiveColor, refractiveColor, fresnelTerm);
float4 dullColor = float4(0.3f, 0.3f, 0.5f, 1.0f);
Output.Color = lerp(combinedColor, dullColor, 0.2f);
float3 reflectionVector = -reflect(xLightDirection, normalVector);
float specular = dot(normalize(reflectionVector), normalize(eyeVector));
specular = pow(abs(specular), 512);
Output.Color.rgb += specular;
return Output;
}
technique Water
{
pass Pass0
{
VertexShader = compile vs_3_0 WaterVS();
PixelShader = compile ps_3_0 WaterPS();
}
}
Do you have any idea what is happening?