2013-12-19 19:32:50 +01:00

45 lines
1.3 KiB
GLSL

// oceanHLSL_Cg.frag
// fragment program for Ocean water simulation
// 04 Aug 2005
// adapted for Ogre by nfz
// original shader source from Render Monkey 1.6 Reflections Refractions.rfx
// can be used in both Cg and HLSL compilers
// 06 Aug 2005: moved uvw calculation from fragment program into vertex program
float4 main(float3 uvw: TEXCOORD0, float3 normal: TEXCOORD1, float3 vVec: TEXCOORD2,
uniform float fadeBias,
uniform float fadeExp,
uniform float4 waterColor,
uniform sampler Noise,
uniform sampler skyBox
) : COLOR
{
float3 noisy = tex3D(Noise, uvw).xyz;
// convert to Signed noise
float3 bump = 2 * noisy - 1;
bump.xz *= 0.15;
// Make sure the normal always points upwards
// note that Ogres y axis is vertical (RM Z axis is vertical)
bump.y = 0.8 * abs(bump.y) + 0.2;
// Offset the surface normal with the bump
bump = normalize(normal + bump);
// Find the reflection vector
float3 normView = normalize(vVec);
float3 reflVec = reflect(normView, bump);
// Ogre has z flipped for cubemaps
reflVec.z = -reflVec.z;
float4 refl = texCUBE(skyBox, reflVec);
// set up for fresnel calc
float lrp = 1 - dot(-normView, bump);
// Interpolate between the water color and reflection for fresnel effect
return lerp(waterColor, refl, saturate(fadeBias + pow(lrp, fadeExp)));
}