TSE Relief Mapping?

by Tim Betts · in Torque Game Engine Advanced · 11/02/2005 (10:37 am) · 156 replies · 6

//Copyright 2007 Matt Vitelli
#define IN_HLSL
#include "shdrConsts.h"

struct v2f
{
	float4 hpos     : POSITION;
	float3 eye      : TEXCOORD0;
	float3 light    : TEXCOORD1;
	float2 texcoord : TEXCOORD2;
};
float3 getLinearStepVal(
	in float4 t,
	in float3 s,
	in float3 ds
)
{

if (s.z<t.w)
s+=ds;

return s;
}

float3 getBinaryStepVal(
	in float4 t,
	in float3 s,
	in float3 ds
)
{
ds*=0.5;
		if (s.z<t.w)
			s+=2*ds;
		s-=ds;

return s;
}
// use linear and binary search
float3 ray_intersect_rm(
      in float4 t,
      in float3 s, 
      in float3 ds)
{
  
   ds/=5;
   float3 linVal1 = getLinearStepVal(t,s,ds);
   float3 linVal2 = getLinearStepVal(t,linVal1,ds);
   float3 linVal3 = getLinearStepVal(t,linVal2,ds);
   float3 linVal4 = getLinearStepVal(t,linVal3,ds);
   float3 linVal5 = getLinearStepVal(t,linVal4,ds);
   float3 binVal1 = getBinaryStepVal(t,linVal5,ds);
   float3 binVal2 = getBinaryStepVal(t,binVal1,ds);
   float3 binVal3 = getBinaryStepVal(t,binVal2,ds);

   return binVal3;
}

float4 main(
	v2f IN,
	uniform sampler2D texmap    : register(S0),
	uniform sampler2D reliefmap : register(S1)
	) : COLOR
{
	
	// view direction
	float3 v = normalize(IN.eye);
	
	// serach start point and serach vector with depth bias
	float3 s = float3(IN.texcoord,0);
	v.xy *= 0.05*(2*v.z-v.z*v.z);
	v /= v.z;
	float4 t = tex2D(reliefmap,s);
	// ray intersect depth map
	float3 tx = ray_intersect_rm(t,s,v);

	// displace start position to intersetcion point
	s.xy += v.xy*tx.z;

	// get normal, lightmap and color at intersection point
	t = tex2D(reliefmap,tx.xy)*2-1;
	float4 c = tex2D(texmap,tx.xy);

	// light direction
	float3 l = normalize(IN.light);
	
	// view direction
	v = normalize(IN.eye);
	v.z = -v.z;

	// compute diffuse and specular terms
	float diff = saturate(dot(l,t.xyz));

	// compute final color
	float4 finalcolor;
	finalcolor.xyz = c*diff;
	finalcolor.w = 1;
        finalcolor /= 2;
	return finalcolor;
}

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