#define _DEBUG_BREAK {gl_FragColor=vec4(1,0,0,1); return;} #define REFRACTION normalize(eta*W + (eta*c1 - sqrt(1.-eta*eta*(1.-c1*c1)))*N) vec3 foregroundColor = vec3(.0841, .5329, .9604); vec3 groundColor = vec3(.2, .3, .5); vec4 groundSpecular = vec4(.71, .71, .71, 10.); uniform float uTime;// TIME, IN SECONDS uniform int f_tex, f_rt, f_moved; uniform float dFL; //DELTA on FOCAL LENGTH uniform mat3 transformation, invTr; uniform vec3 Ambient[ns], Diffuse[ns]; uniform vec4 Specular[ns]; uniform float ks[ns], kr[ns], kf[ns]; uniform vec4 Sph[ns]; uniform sampler2D uSampler[ns]; const float kf_air = 1.000293; varying vec3 vPos; float fl=3.;//ORIGINAL FOCAL LENGTH const float pi=3.14159265359; const float _2pi=2.*pi; /***********PLEASE DO INCREASE n_ref(RT DEPTH) FOR BETTER RESULTS************/ /*---->*/const int n_ref=31; //2^n-1 because each hit now spawn at most 2 rays. /**BUT BE CAUTIOUS IF YOU DON'T HAVE A DECENT GRAPHICS CARD (below GTX 950M)**/ const int max_stack = (n_ref+1)/4; vec3 scolor = vec3(0,0,0); //Actually 2^n_ref struct Ray{ vec3 V; vec3 W; float kf, cumulativeK; } stack1[max_stack], stack2[max_stack]; bool modulo2(int n){ return n-2*(n/2) == 1; } vec2 getTextCoord(vec3 tex_sph, float R){ float tex_x=acos(abs(tex_sph.x)/sqrt(R*R-tex_sph.y*tex_sph.y)); if(tex_sph.x>0.) tex_x=pi-tex_x; tex_x*=1.5708;//*Correct aspect ratio of texture 2:1 -> 2pir:2r tex_x=tex_x+float(uTime); float quo=float(int(tex_x/_2pi)); tex_x=tex_x/_2pi - quo; return vec2(tex_x,((R-tex_sph.y)/(2.*R))); } void main(){ vec3 LDir=vec3(.5,.5,.5); vec3 LCol=vec3(1.,1.,1.); float currKf = kf_air; vec3 color=vec3(.2, .3, .5); vec3 trPos = transformation*((dFL+fl+1.)/(fl+1.))*vec3(vPos.xy, -1); vec3 V0=transformation*vec3(0.,0.,fl+dFL), V = V0; vec3 W=(trPos-V); bool rtxoff = false, showtexture = true, moved = false; float currentK = 1.; int curr_ptr = 0, curr_top = 0, next_top = 0; bool final = false, stackswap = false; for(int j=0;j 0){ Ray currR; if(stackswap) currR = stack1[curr]; else currR = stack2[curr]; currKf = currR.kf; currentK = currR.cumulativeK; if(currKf <= 0.001 || currentK <= 0.001) skip = true; V = currR.V; W = currR.W; } else W = normalize(W); if(!skip){ float tMin=10000.; int iMin = -1; for(int i=0;i0.){ float t=-B-sqrt(D); if(t >= 0.01 && t < tMin){ tMin = t; // This is an optimization, we don't have to do lighting/tex iMin = i; // for objects that are occuluded, which is expensive! } else if (t >= -0.01 && t <0.01){ t = -(t + 2.*B); if(t > 0.01 && t < tMin){ tMin = t; iMin = i; } } } } if(iMin >= 0){ float t = tMin; vec3 S=V+t*W; for(int i = 0; i < cns; ++ i) if(i == iMin) { vec3 texture_color; if(showtexture) { vec3 tex_sph = (S-Sph[i].xyz); if(moved) ;//tex_sph=invTr*tex_sph;　too expensive texture_color=texture2D(uSampler[i],getTextCoord(tex_sph, Sph[i].w)).xyz; } else texture_color = foregroundColor; vec3 N=normalize(S-Sph[i].xyz); vec3 realLDir=normalize(LDir-S); float c1 =dot(N, W); if(c1<0.){ color=(Ambient[i]+Diffuse[i]*max(0.,dot(N,realLDir))*LCol)*texture_color; if(rtxoff || final) //if it's the last hit { color += Specular[i].xyz*pow(max(0., dot(-2.*c1*N-realLDir,realLDir)),Specular[i].w); scolor += color * currentK; } else{ c1 = -c1; float eta =currKf/kf[i]; float nextks = currentK * ks[i], nextkr = currentK * kr[i]; bool refl = nextks > 0.001, refr = nextkr > 0.001; if(refl || refr) for(int k = 0; k < max_stack; ++k) if(k == next_top){ if(stackswap){ if(refl) { stack2[k] = Ray(S, 2. * c1 * N + W, currKf, nextks); //reflection currentK -= nextks; next_top ++; } if(refr) { if(refl) stack2[k+1] = Ray(S, REFRACTION, kf[i], nextkr); //refraction else stack2[k] = Ray(S, REFRACTION, kf[i], nextkr); //refraction currentK -= nextkr; next_top ++; } }else{ if(refl) { //remember, c1 = -NW now stack1[k] = Ray(S, 2. * c1 * N + W, currKf, nextks); //reflection currentK -= nextks; next_top ++; } if(refr) { if(refl) stack1[k+1] = Ray(S, REFRACTION, kf[i], nextkr); //refraction else stack1[k] = Ray(S, REFRACTION, kf[i], nextkr); //refraction currentK -= nextkr; next_top ++; } } break; } scolor += currentK * color; } } else{ float eta = currKf/kf_air; N = -N; //inside the sphere, normal is inward! float c2 = (1.-eta*eta*(1.-c1*c1)); for(int k = 0; k < max_stack; ++k) if(k == next_top){ if(stackswap) { stack2[k+1] = Ray(S, -2. * c1 * N + W, currKf, currentK*ks[i]); //reflection inside if(c2 >= 0.) stack2[k] = Ray(S, normalize(eta*W + (eta*c1 - sqrt(c2))*N), kf_air, currentK*kr[i]); //refraction else //on the edge, the light won't bend anymore and will keep perpendicular to normal stack2[k] = Ray(S, normalize((W + c1*N)/sqrt(1.-c1*c1)), kf_air, currentK*kr[i]); //refraction }else{ stack1[k+1] = Ray(S, -2. * c1 * N + W, currKf, currentK*ks[i]); //reflection inside if(c2 >= 0.) stack1[k] = Ray(S, normalize(eta*W + (eta*c1 - sqrt(c2))*N), kf_air, currentK*kr[i]); //refraction else stack1[k] = Ray(S, normalize((W + c1*N)/sqrt(1.-c1*c1)), kf_air, currentK*kr[i]); //refraction } next_top += 2; break; } } break; } } else { float t = -(.2+V.y)/W.y; float sx = V.x + t* W.x, sz = V.z + t * W.z; if(t >= 0. && abs(sx) < 1.5 && abs(sz) < 3.) { vec3 S = vec3(sx, -.2, sz); vec3 realLDir=normalize(LDir - S); color=(0.5+0.5*max(0.,realLDir.y)*LCol)*texture2D(uSampler[4],vec2((sx+1.4)/3., (sz+1.5)/4.)).xyz; if(rtxoff || final&&abs(sx)<1.5 && abs(sz+.6)<3.) { color += groundSpecular.xyz* //specular for ground. pow(max(0., dot(vec3(-realLDir.x, realLDir.y,-realLDir.z),-W)),groundSpecular.w); scolor += currentK * color; } else { for(int k = 0; k < max_stack; ++k) if(k == next_top){ if(stackswap) stack2[k] = Ray(S, vec3(W.x, -W.y, W.z), kf_air, currentK * 0.15); //reflection else stack1[k] = Ray(S, vec3(W.x, -W.y, W.z), kf_air, currentK * 0.15); //reflection next_top ++; break; } scolor += (currentK*.85)*color; } } else{ if(j > 0) scolor += currentK * (pow(max(0.,dot(W, normalize(LDir - V))), 10.) * vec3(1.,1.,1.) + foregroundColor*0.1); else scolor = foregroundColor*0.6; } } } if(++curr_ptr >= curr_top){ curr_top = next_top; curr_ptr = 0; if(next_top * 2 > max_stack) final = true; stackswap = !stackswap; } break; } } } gl_FragColor=vec4(sqrt(scolor),1.); }