Clipping planes in Shader Model 2.0

I am not sure and i had no time to test it but there is a HLSL clip function, so you might use point-plane relationship function for parameter, something like:

void VertexMain(...)
{
    ...
    OUT.worlPos = mul( IN.Position, World );
}
 
float4 plane; // water plane
 
void PixelMain()
{
    ...
    clip( dot( IN.worldPos, plane.xyz ) + plane.w );
}

BTW. Isn't clipping used for reflection and not for refraction?

I might give that a try, thanks! I was thinking of finding the distance of the point from the plane, but I didn't know about the clip() function. I actually tried without clipping, and you're right - it works just fine. I guess it makes sense since you only sample from the part of the image which shows the underwater stuff anyway. For some reason the Rastertek tutorial on refraction mapping uses clipping - maybe it's slightly faster to not render the whole scene to the refraction map? Anyway, here's how it looks:

[attachment=15982:RefractingWater3.png]

[attachment=15983:RefractingWater1.png]

Nice results.