shader复习
// Created by inigo quilez - iq/2015 // I share this piece (art and code) here in Shadertoy and through its Public API, only for educational purposes. // You cannot use, sell, share or host this piece or modifications of it as part of your own commercial or non-commercial product, website or project. // You can share a link to it or an unmodified screenshot of it provided you attribute "by Inigo Quilez, @iquilezles and iquilezles.org". // If you are a teacher, lecturer, educator or similar and these conditions are too restrictive for your needs, please contact me and we'll work it out. // You can buy a metal print of this shader here: // https://www.redbubble.com/i/metal-print/Snail-by-InigoQuilez/39845499.0JXQP // antialiasing - make AA 2, meaning 4x AA, if you have a fast machine #define AA 1 #define ZERO (min(iFrame,0)) // http://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float sdSphere( in vec3 p, in vec4 s ) { return length(p-s.xyz) - s.w; } // http://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float sdEllipsoid( in vec3 p, in vec3 c, in vec3 r ) { return (length( (p-c)/r ) - 1.0) * min(min(r.x,r.y),r.z); } // http://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float sdCircle( in vec2 p, in vec2 c, in float r ) { return length(p-c) - r; } // http://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float sdTorus( vec3 p, vec2 t ) { return length( vec2(length(p.xz)-t.x,p.y) )-t.y; } // http://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float sdCapsule( vec3 p, vec3 a, vec3 b, float r ) { vec3 pa = p-a, ba = b-a; float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 ); return length( pa - ba*h ) - r; } // http://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm vec2 udSegment( vec3 p, vec3 a, vec3 b ) { vec3 pa = p-a, ba = b-a; float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 ); return vec2( length( pa - ba*h ), h ); } // http://research.microsoft.com/en-us/um/people/hoppe/ravg.pdf float det( vec2 a, vec2 b ) { return a.x*b.y-b.x*a.y; } vec3 getClosest( vec2 b0, vec2 b1, vec2 b2 ) { float a = det(b0,b2); float b = 2.0*det(b1,b0); float d = 2.0*det(b2,b1); float f = b*d - a*a; vec2 d21 = b2-b1; vec2 d10 = b1-b0; vec2 d20 = b2-b0; vec2 gf = 2.0*(b*d21+d*d10+a*d20); gf = vec2(gf.y,-gf.x); vec2 pp = -f*gf/dot(gf,gf); vec2 d0p = b0-pp; float ap = det(d0p,d20); float bp = 2.0*det(d10,d0p); float t = clamp( (ap+bp)/(2.0*a+b+d), 0.0 ,1.0 ); return vec3( mix(mix(b0,b1,t), mix(b1,b2,t),t), t ); } vec4 sdBezier( vec3 a, vec3 b, vec3 c, vec3 p ) { vec3 w = normalize( cross( c-b, a-b ) ); vec3 u = normalize( c-b ); vec3 v = ( cross( w, u ) ); vec2 a2 = vec2( dot(a-b,u), dot(a-b,v) ); vec2 b2 = vec2( 0.0 ); vec2 c2 = vec2( dot(c-b,u), dot(c-b,v) ); vec3 p3 = vec3( dot(p-b,u), dot(p-b,v), dot(p-b,w) ); vec3 cp = getClosest( a2-p3.xy, b2-p3.xy, c2-p3.xy ); return vec4( sqrt(dot(cp.xy,cp.xy)+p3.z*p3.z), cp.z, length(cp.xy), p3.z ); } // http://iquilezles.org/www/articles/smin/smin.htm float smin( float a, float b, float k ) { float h = max(k-abs(a-b),0.0); return min(a, b) - h*h*0.25/k; } // http://iquilezles.org/www/articles/smin/smin.htm float smax( float a, float b, float k ) { float h = max(k-abs(a-b),0.0); return max(a, b) + h*h*0.25/k; } // http://iquilezles.org/www/articles/smin/smin.htm vec3 smax( vec3 a, vec3 b, float k ) { vec3 h = max(k-abs(a-b),0.0); return max(a, b) + h*h*0.25/k; } //--------------------------------------------------------------------------- float hash1( float n ) { return fract(sin(n)*43758.5453123); } vec3 forwardSF( float i, float n) { const float PI = 3.141592653589793238; const float PHI = 1.618033988749894848; float phi = 2.0*PI*fract(i/PHI); float zi = 1.0 - (2.0*i+1.0)/n; float sinTheta = sqrt( 1.0 - zi*zi); return vec3( cos(phi)*sinTheta, sin(phi)*sinTheta, zi); } //--------------------------------------------------------------------------- const float pi = 3.1415927; //--------------------------------------------------------------------------- float mapShell( in vec3 p, out vec4 matInfo ) { p -= vec3(0.05,0.12,-0.09); vec3 q = mat3(-0.6333234236, -0.7332753384, 0.2474039592, 0.7738444477, -0.6034162289, 0.1924931824, 0.0081370606, 0.3133626215, 0.9495986813) * p; const float b = 0.1759; float r = length( q.xy ); float t = atan( q.y, q.x ); // https://swiftcoder.wordpress.com/2010/06/21/logarithmic-spiral-distance-field/ float np = (log( r)/b-t)/(2.0*pi); float nm = (log(0.11)/b-t)/(2.0*pi); float n = min(np,nm); float ni = floor( n ); float r1 = exp( b * (t + 2.0*pi*ni)); float r2 = r1 * 3.019863; //------- float h1 = q.z + 1.5*r1 - 0.5; float d1 = sqrt((r1-r)*(r1-r)+h1*h1) - r1; float h2 = q.z + 1.5*r2 - 0.5; float d2 = sqrt((r2-r)*(r2-r)+h2*h2) - r2; float d, dx, dy; if( d1<d2 ) { d = d1; dx=r1-r; dy=h1; } else { d = d2; dx=r2-r; dy=h2; } float di = textureLod( iChannel2, vec2(t+r,0.5), 0. ).x; d += 0.002*di; matInfo = vec4(dx,dy,r/0.4,t/pi); vec3 s = q; q = q - vec3(0.34,-0.1,0.03); q.xy = mat2(0.8,0.6,-0.6,0.8)*q.xy; d = smin( d, sdTorus( q, vec2(0.28,0.05) ), 0.06); d = smax( d, -sdEllipsoid(q,vec3(0.0,0.0,0.0),vec3(0.24,0.36,0.24) ), 0.03 ); d = smax( d, -sdEllipsoid(s,vec3(0.52,-0.0,0.0),vec3(0.42,0.23,0.5) ), 0.05 ); return d; } vec2 mapSnail( vec3 p, out vec4 matInfo ) { const vec3 head = vec3(-0.76,0.6,-0.3); vec3 q = p - head; // body vec4 b1 = sdBezier( vec3(-0.13,-0.65,0.0), vec3(0.24,0.9+0.1,0.0), head+vec3(0.04,0.01,0.0), p ); float d1 = b1.x; d1 -= smoothstep(0.0,0.2,b1.y)*(0.16 - 0.07*smoothstep(0.5,1.0,b1.y)); b1 = sdBezier( vec3(-0.085,0.0,0.0), vec3(-0.1,0.9-0.05,0.0), head+vec3(0.06,-0.08,0.0), p ); float d2 = b1.x; d2 -= 0.1 - 0.06*b1.y; d1 = smin( d1, d2, 0.03 ); matInfo.xyz = b1.yzw; d2 = sdSphere( q, vec4(0.0,-0.06,0.0,0.085) ); d1 = smin( d1, d2, 0.03 ); d1 = smin( d1, sdSphere(p,vec4(0.05,0.52,0.0,0.13)), 0.07 ); q.xz = mat2(0.8,0.6,-0.6,0.8)*q.xz; vec3 sq = vec3( q.xy, abs(q.z) ); // top antenas vec3 af = 0.05*sin(0.5*iTime+vec3(0.0,1.0,3.0) + vec3(2.0,1.0,0.0)*sign(q.z) ); vec4 b2 = sdBezier( vec3(0.0), vec3(-0.1,0.2,0.2), vec3(-0.3,0.2,0.3)+af, sq ); float d3 = b2.x; d3 -= 0.03 - 0.025*b2.y; d1 = smin( d1, d3, 0.04 ); d3 = sdSphere( sq, vec4(-0.3,0.2,0.3,0.016) + vec4(af,0.0) ); d1 = smin( d1, d3, 0.01 ); // bottom antenas vec3 bf = 0.02*sin(0.3*iTime+vec3(4.0,1.0,2.0) + vec3(3.0,0.0,1.0)*sign(q.z) ); vec2 b3 = udSegment( sq, vec3(0.06,-0.05,0.0), vec3(-0.04,-0.2,0.18)+bf ); d3 = b3.x; d3 -= 0.025 - 0.02*b3.y; d1 = smin( d1, d3, 0.06 ); d3 = sdSphere( sq, vec4(-0.04,-0.2,0.18,0.008)+vec4(bf,0.0) ); d1 = smin( d1, d3, 0.02 ); // bottom vec3 pp = p-vec3(-0.17,0.15,0.0); float co = 0.988771078; float si = 0.149438132; pp.xy = mat2(co,-si,si,co)*pp.xy; d1 = smin( d1, sdEllipsoid( pp, vec3(0.0,0.0,0.0), vec3(0.084,0.3,0.15) ), 0.05 ); d1 = smax( d1, -sdEllipsoid( pp, vec3(-0.08,-0.0,0.0), vec3(0.06,0.55,0.1) ), 0.02 ); // disp float dis = textureLod( iChannel1, 5.0*p.xy, 0. ).x; float dx = 0.5 + 0.5*(1.0-smoothstep(0.5,1.0,b1.y)); d1 -= 0.005*dis*dx*0.5; return vec2(d1,1.0); } float mapDrop( in vec3 p ) { p -= vec3(-0.26,0.25,-0.02); p.x -= 2.5*p.y*p.y; return sdCapsule( p, vec3(0.0,-0.06,0.0), vec3(0.014,0.06,0.0), 0.037 ); } float mapLeaf( in vec3 p ) { p -= vec3(-1.8,0.6,-0.75); p = mat3(0.671212, 0.366685, -0.644218, -0.479426, 0.877583, 0.000000, 0.565354, 0.308854, 0.764842)*p; p.y += 0.2*exp2(-abs(2.9*p.z) ); float ph = 0.25*50.0*p.x - 0.25*75.0*abs(p.z); float rr = sin( ph ); rr = rr*rr; rr = rr*rr; p.y += 0.005*rr; float r = clamp((p.x+2.0)/4.0,0.0,1.0); r = 0.0001 + r*(1.0-r)*(1.0-r)*6.0; rr = sin( ph*2.0 ); rr = rr*rr; rr *= 0.5+0.5*sin( p.x*12.0 ); float ri = 0.035*rr; float d = sdEllipsoid( p, vec3(0.0), vec3(2.0,0.25*r,r+ri) ); float d2 = p.y-0.02; return smax( d, -d2, 0.02 ); } vec2 mapOpaque( vec3 p, out vec4 matInfo ) { matInfo = vec4(0.0); // leaf vec2 res = vec2( mapLeaf( p ), 4.0); // stem vec4 b3 = sdBezier( vec3(-0.15,-1.5,0.0), vec3(-0.1,0.5,0.0), vec3(-0.6,1.5,0.0), p ); float d3 = b3.x - 0.04 + 0.02*b3.y; if( d3<res.x ) res = vec2(d3,3.0); // snail float boundingVolume = sdCapsule(p, vec3(0.0), vec3(-0.6,0.7,0.0), 0.55); if( boundingVolume<res.x ) { vec2 tmp = mapSnail( p, matInfo ); if( tmp.x<res.x ) { res = tmp; } // shell float bb = length( p-vec3(0.25,0.3,-0.1) )-0.6; if( bb<res.x ) { vec4 tmpMatInfo; float d4 = mapShell( p, tmpMatInfo ); if( d4<res.x ) { res = vec2(d4,2.0); matInfo = tmpMatInfo; } } } return res; } // http://iquilezles.org/www/articles/normalsSDF/normalsSDF.htm vec3 calcNormalOpaque( in vec3 pos, in float eps ) { vec4 kk; #if 0 vec2 e = vec2(1.0,-1.0)*0.5773*eps; return normalize( e.xyy*mapOpaque( pos + e.xyy, kk ).x + e.yyx*mapOpaque( pos + e.yyx, kk ).x + e.yxy*mapOpaque( pos + e.yxy, kk ).x + e.xxx*mapOpaque( pos + e.xxx, kk ).x ); #else // inspired by tdhooper and klems - a way to prevent the compiler from inlining map() 4 times vec3 n = vec3(0.0); for( int i=ZERO; i<4; i++ ) { vec3 e = 0.5773*(2.0*vec3((((i+3)>>1)&1),((i>>1)&1),(i&1))-1.0); n += e*mapOpaque(pos+eps*e,kk).x; } return normalize(n); #endif } //========================================================================= float mapLeafWaterDrops( in vec3 p ) { p -= vec3(-1.8,0.6,-0.75); vec3 s = p; p = mat3(0.671212, 0.366685, -0.644218, -0.479426, 0.877583, 0.000000, 0.565354, 0.308854, 0.764842)*p; vec3 q = p; p.y += 0.2*exp(-abs(2.0*p.z) ); float r = clamp((p.x+2.0)/4.0,0.0,1.0); r = r*(1.0-r)*(1.0-r)*6.0; float d1 = sdEllipsoid( q, vec3(0.5,0.0,0.2), 1.0*vec3(0.15,0.13,0.15) ); float d2 = sdEllipsoid( q, vec3(0.8,-0.07,-0.15), 0.5*vec3(0.15,0.13,0.15) ); float d3 = sdEllipsoid( s, vec3(0.76,-0.8,0.6), 0.5*vec3(0.15,0.2,0.15) ); float d4 = sdEllipsoid( q, vec3(-0.5,0.09,-0.2), vec3(0.04,0.03,0.04) ); d3 = max( d3, p.y-0.01); return min( min(d1,d4), min(d2,d3) ); } vec2 mapTransparent( vec3 p, out vec4 matInfo ) { matInfo = vec4(0.0); float d5 = mapDrop( p ); vec2 res = vec2(d5,4.0); float d6 = mapLeafWaterDrops( p ); res.x = min( res.x, d6 ); return res; } // http://iquilezles.org/www/articles/normalsSDF/normalsSDF.htm vec3 calcNormalTransparent( in vec3 pos, in float eps ) { vec4 kk; vec2 e = vec2(1.0,-1.0)*0.5773*eps; return normalize( e.xyy*mapTransparent( pos + e.xyy, kk ).x + e.yyx*mapTransparent( pos + e.yyx, kk ).x + e.yxy*mapTransparent( pos + e.yxy, kk ).x + e.xxx*mapTransparent( pos + e.xxx, kk ).x ); } //========================================================================= float calcAO( in vec3 pos, in vec3 nor ) { vec4 kk; float ao = 0.0; for( int i=ZERO; i<32; i++ ) { vec3 ap = forwardSF( float(i), 32.0 ); float h = hash1(float(i)); ap *= sign( dot(ap,nor) ) * h*0.1; ao += clamp( mapOpaque( pos + nor*0.01 + ap, kk ).x*3.0, 0.0, 1.0 ); } ao /= 32.0; return clamp( ao*6.0, 0.0, 1.0 ); } float calcSSS( in vec3 pos, in vec3 nor ) { vec4 kk; float occ = 0.0; for( int i=ZERO; i<8; i++ ) { float h = 0.002 + 0.11*float(i)/7.0; vec3 dir = normalize( sin( float(i)*13.0 + vec3(0.0,2.1,4.2) ) ); dir *= sign(dot(dir,nor)); occ += (h-mapOpaque(pos-h*dir, kk).x); } occ = clamp( 1.0 - 11.0*occ/8.0, 0.0, 1.0 ); return occ*occ; } // http://iquilezles.org/www/articles/rmshadows/rmshadows.htm float calcSoftShadow( in vec3 ro, in vec3 rd, float k ) { vec4 kk; float res = 1.0; float t = 0.01; for( int i=ZERO; i<32; i++ ) { float h = mapOpaque(ro + rd*t, kk ).x; res = min( res, smoothstep(0.0,1.0,k*h/t) ); t += clamp( h, 0.04, 0.1 ); if( res<0.01 ) break; } return clamp(res,0.0,1.0); } const vec3 sunDir = normalize( vec3(0.2,0.1,0.02) ); vec3 shadeOpaque( in vec3 ro, in vec3 rd, in float t, in float m, in vec4 matInfo ) { float eps = 0.002; vec3 pos = ro + t*rd; vec3 nor = calcNormalOpaque( pos, eps ); vec3 mateD = vec3(0.0); vec3 mateS = vec3(0.0); vec2 mateK = vec2(0.0); vec3 mateE = vec3(0.0); float focc = 1.0; float fsha = 1.0; if( m<1.5 ) // snail body { float dis = texture( iChannel1, 5.0*pos.xy ).x; float be = sdEllipsoid( pos, vec3(-0.3,-0.5,-0.1), vec3(0.2,1.0,0.5) ); be = 1.0-smoothstep( -0.01, 0.01, be ); float ff = abs(matInfo.x-0.20); mateS = 6.0*mix( 0.7*vec3(2.0,1.2,0.2), vec3(2.5,1.8,0.9), ff ); mateS += 2.0*dis; mateS *= 1.5; mateS *= 1.0 + 0.5*ff*ff; mateS *= 1.0-0.5*be; mateD = vec3(1.0,0.8,0.4); mateD *= dis; mateD *= 0.015; mateD += vec3(0.8,0.4,0.3)*0.15*be; mateK = vec2( 60.0, 0.7 + 2.0*dis ); float f = clamp( dot( -rd, nor ), 0.0, 1.0 ); f = 1.0-pow( f, 8.0 ); f = 1.0 - (1.0-f)*(1.0-texture( iChannel2, 0.3*pos.xy ).x); mateS *= vec3(0.5,0.1,0.0) + f*vec3(0.5,0.9,1.0); float b = 1.0-smoothstep( 0.25,0.55,abs(pos.y)); focc = 0.2 + 0.8*smoothstep( 0.0, 0.15, sdSphere(pos,vec4(0.05,0.52,0.0,0.13)) ); } else if( m<2.5 ) // shell { mateK = vec2(0.0); float tip = 1.0-smoothstep(0.05,0.4, length(pos-vec3(0.17,0.2,0.35)) ); mateD = mix( 0.7*vec3(0.2,0.21,0.22), 0.2*vec3(0.15,0.1,0.0), tip ); vec2 uv = vec2( .5*atan(matInfo.x,matInfo.y)/3.1416, 1.5*matInfo.w ); vec3 ral = texture( iChannel1, vec2(2.0*matInfo.w+matInfo.z*0.5,0.5) ).xxx; mateD *= 0.25 + 0.75*ral; float pa = smoothstep(-0.2,0.2, 0.3+sin(2.0+40.0*uv.x + 3.0*sin(11.0*uv.x)) ); float bar = mix(pa,1.0,smoothstep(0.7,1.0,tip)); bar *= (matInfo.z<0.6) ? 1.0 : smoothstep( 0.17, 0.21, abs(matInfo.w) ); mateD *= vec3(0.06,0.03,0.0)+vec3(0.94,0.97,1.0)*bar; mateK = vec2( 64.0, 0.2 ); mateS = 1.5*vec3(1.0,0.65,0.6) * (1.0-tip);//*0.5; } else if( m<3.5 ) // plant { mateD = vec3(0.05,0.1,0.0)*0.2; mateS = vec3(0.1,0.2,0.02)*25.0; mateK = vec2(5.0,1.0); float fre = clamp(1.0+dot(nor,rd), 0.0, 1.0 ); mateD += 0.2*fre*vec3(1.0,0.5,0.1); vec3 te = texture( iChannel2, pos.xy*0.2 ).xyz; mateS *= 0.5 + 1.5*te; mateE = 0.5*vec3(0.1,0.1,0.03)*(0.2+0.8*te.x); } else //if( m<4.5 ) // leaf { vec3 p = pos - vec3(-1.8,0.6,-0.75); vec3 s = p; p = mat3(0.671212, 0.366685, -0.644218, -0.479426, 0.877583, 0.000000, 0.565354, 0.308854, 0.764842)*p; vec3 q = p; p.y += 0.2*exp(-abs(2.0*p.z) ); float v = smoothstep( 0.01, 0.02, abs(p.z)); float rr = sin( 4.0*0.25*50.0*p.x - 4.0*0.25*75.0*abs(p.z) ); vec3 te = texture( iChannel2, p.xz*0.35 ).xyz; float r = clamp((p.x+2.0)/4.0,0.0,1.0); r = r*(1.0-r)*(1.0-r)*6.0; float ff = length(p.xz/vec2(2.0,r)); mateD = mix( vec3(0.07,0.1,0.0), vec3(0.05,0.2,0.01)*0.25, v ); mateD = mix( mateD, vec3(0.16,0.2,0.01)*0.25, ff ); mateD *= 1.0 + 0.25*te; mateD *= 0.8; mateS = vec3(0.15,0.2,0.02)*0.8; mateS *= 1.0 + 0.2*rr; mateS *= 0.8; mateK = vec2(64.0,0.25); //--------------------- nor.xz += v*0.15*(-1.0+2.0*texture( iChannel3, 1.0*p.xz ).xy); nor = normalize( nor ); float d1 = sdEllipsoid( q, vec3( 0.5-0.07, 0.0, 0.20), 1.0*vec3(1.4*0.15,0.13,0.15) ); float d2 = sdEllipsoid( q, vec3( 0.8-0.05,-0.07,-0.15), 0.5*vec3(1.3*0.15,0.13,0.15) ); float d4 = sdEllipsoid( q, vec3(-0.5-0.07, 0.09,-0.20), 1.0*vec3(1.4*0.04,0.03,0.04) ); float dd = min(d1,min(d2,d4)); fsha = 0.05 + 0.95*smoothstep(0.0,0.05,dd); d1 = abs( sdCircle( q.xz, vec2( 0.5, 0.20), 1.0*0.15 )); d2 = abs( sdCircle( q.xz, vec2( 0.8,-0.15), 0.5*0.15 )); d4 = abs( sdCircle( q.xz, vec2(-0.5,-0.20), 1.0*0.04 )); dd = min(d1,min(d2,d4)); focc *= 0.55 + 0.45*smoothstep(0.0,0.08,dd); d1 = distance( q.xz, vec2( 0.5-0.07, 0.20) ); d2 = distance( q.xz, vec2( 0.8-0.03,-0.15) ); fsha += (1.0-smoothstep(0.0,0.10,d1))*1.5; fsha += (1.0-smoothstep(0.0,0.05,d2))*1.5; } vec3 hal = normalize( sunDir-rd ); float fre = clamp(1.0+dot(nor,rd), 0.0, 1.0 ); float occ = calcAO( pos, nor )*focc; float sss = calcSSS( pos, nor ); sss = sss*occ + fre*occ + (0.5+0.5*fre)*pow(abs(matInfo.x-0.2),1.0)*occ; float dif1 = clamp( dot(nor,sunDir), 0.0, 1.0 ); dif1 *= fsha; float sha = 1.0; if( dif1>0.0001 ) sha=calcSoftShadow( pos, sunDir, 20.0 ); dif1 *= sha; float spe1 = clamp( dot(nor,hal), 0.0, 1.0 ); float bou = clamp( 0.3-0.7*nor.y, 0.0, 1.0 ); // illumination vec3 col = vec3(0.0); col += 7.0*vec3(1.7,1.2,0.6)*dif1*2.0; // sun col += 4.0*vec3(0.2,1.2,1.6)*occ*(0.5+0.5*nor.y); // sky col += 1.8*vec3(0.1,2.0,0.1)*bou*occ; // bounce col *= mateD; col += 0.4*sss*(vec3(0.15,0.1,0.05)+vec3(0.85,0.9,0.95)*dif1)*(0.05+0.95*occ)*mateS; // sss col = pow(col,vec3(0.6,0.8,1.0)); col += vec3(1.0,1.0,1.0)*0.2*pow( spe1, 1.0+mateK.x )*dif1*(0.04+0.96*pow(fre,4.0))*mateK.x*mateK.y; // sun lobe1 col += vec3(1.0,1.0,1.0)*0.1*pow( spe1, 1.0+mateK.x/3.0 )*dif1*(0.1+0.9*pow(fre,4.0))*mateK.x*mateK.y; // sun lobe2 col += 0.1*vec3(1.0,max(1.5-0.7*col.y,0.0),2.0)*occ*occ*smoothstep( 0.0, 0.3, reflect( rd, nor ).y )*mateK.x*mateK.y*(0.04+0.96*pow(fre,5.0)); // sky col += mateE; return col; } vec3 shadeTransparent( in vec3 ro, in vec3 rd, in float t, in float m, in vec4 matInfo, in vec3 col, in float depth ) { vec3 oriCol = col; float dz = depth - t; float ao = clamp(dz*50.0,0.0,1.0); vec3 pos = ro + t*rd; vec3 nor = calcNormalTransparent( pos, 0.002 ); float fre = clamp( 1.0 + dot( rd, nor ), 0.0, 1.0 ); vec3 hal = normalize( sunDir-rd ); vec3 ref = reflect( -rd, nor ); float spe1 = clamp( dot(nor,hal), 0.0, 1.0 ); float spe2 = clamp( dot(ref,sunDir), 0.0, 1.0 ); float ds = 1.6 - col.y; col *= mix( vec3(0.0,0.0,0.0), vec3(0.4,0.6,0.4), ao ); col += ds*1.5*vec3(1.0,0.9,0.8)*pow( spe1, 80.0 ); col += ds*0.2*vec3(0.9,1.0,1.0)*smoothstep(0.4,0.8,fre); col += ds*0.9*vec3(0.6,0.7,1.0)*smoothstep( -0.5, 0.5, -reflect( rd, nor ).y )*smoothstep(0.2,0.4,fre); col += ds*0.5*vec3(1.0,0.9,0.8)*pow( spe2, 80.0 ); col += ds*0.5*vec3(1.0,0.9,0.8)*pow( spe2, 16.0 ); col += vec3(0.8,1.0,0.8)*0.5*smoothstep(0.3,0.6,texture( iChannel1, 0.8*nor.xy ).x)*(0.1+0.9*fre*fre); // hide aliasing a bit return mix( col, oriCol, smoothstep(0.6,1.0,fre) ); } //-------------------------------------------- vec2 intersectOpaque( in vec3 ro, in vec3 rd, const float mindist, const float maxdist, out vec4 matInfo ) { vec2 res = vec2(-1.0); float t = mindist; for( int i=ZERO; i<128; i++ ) { vec3 p = ro + t*rd; vec2 h = mapOpaque( p, matInfo ); res = vec2(t,h.y); if( h.x<(0.001*t) || t>maxdist ) break; t += h.x*0.9; } return res; } vec2 intersectTransparent( in vec3 ro, in vec3 rd, const float mindist, const float maxdist, out vec4 matInfo ) { vec2 res = vec2(-1.0); float t = mindist; for( int i=ZERO; i<64; i++ ) { vec3 p = ro + t*rd; vec2 h = mapTransparent( p, matInfo ); res = vec2(t,h.y); if( h.x<(0.001*t) || t>maxdist ) break; t += h.x; } return res; } vec3 background( in vec3 d ) { // cheap cubemap vec3 n = abs(d); vec2 uv = (n.x>n.y && n.x>n.z) ? d.yz/d.x: (n.y>n.x && n.y>n.z) ? d.zx/d.y: d.xy/d.z; // fancy blur vec3 col = vec3( 0.0 ); for( int i=ZERO; i<200; i++ ) { float h = float(i)/200.0; float an = 31.0*6.2831*h; vec2 of = vec2( cos(an), sin(an) ) * h; vec3 tmp = texture( iChannel2, uv*0.25 + 0.0075*of, 4.0 ).yxz; col = smax( col, tmp, 0.5 ); } return pow(col,vec3(3.5,3.0,6.0))*0.2; } vec3 render( in vec3 ro, in vec3 rd, in vec2 q ) { //----------------------------- vec3 col = background( rd ); //----------------------------- float mindist = 1.0; float maxdist = 4.0; vec4 matInfo; vec2 tm = intersectOpaque( ro, rd, mindist, maxdist, matInfo ); if( tm.y>-0.5 && tm.x < maxdist ) { col = shadeOpaque( ro, rd, tm.x, tm.y, matInfo ); maxdist = tm.x; } //----------------------------- tm = intersectTransparent( ro, rd, mindist, maxdist, matInfo ); if( tm.y>-0.5 && tm.x < maxdist ) { col = shadeTransparent( ro, rd, tm.x, tm.y, matInfo, col, maxdist ); } //----------------------------- float sun = clamp(dot(rd,sunDir),0.0,1.0); col += 1.0*vec3(1.5,0.8,0.7)*pow(sun,4.0); //----------------------------- col = pow( col, vec3(0.45) ); col = vec3(1.05,1.0,1.0)*col*(0.7+0.3*col*max(3.0-2.0*col,0.0)) + vec3(0.0,0.0,0.04); col *= 0.3 + 0.7*pow(16.0*q.x*q.y*(1.0-q.x)*(1.0-q.y),0.1); return clamp( col, 0.0, 1.0 ); } mat3 setCamera( in vec3 ro, in vec3 rt ) { vec3 w = normalize(ro-rt); float m = sqrt(1.0-w.y*w.y); return mat3( w.z, 0.0, -w.x, 0.0, m*m, -w.z*w.y, w.x*m, w.y*m, w.z*m ); } void mainImage( out vec4 fragColor, in vec2 fragCoord ) { #if AA<2 vec2 p = (2.0*fragCoord-iResolution.xy)/iResolution.y; vec2 q = fragCoord/iResolution.xy; float an = 1.87 - 0.04*(1.0-cos(0.5*iTime)); vec3 ro = vec3(-0.4,0.2,0.0) + 2.2*vec3(cos(an),0.0,sin(an)); vec3 ta = vec3(-0.6,0.2,0.0); mat3 ca = setCamera( ro, ta ); vec3 rd = normalize( ca * vec3(p,-2.8) ); vec3 col = render( ro, rd, q ); #else vec3 col = vec3(0.0); for( int m=ZERO; m<AA; m++ ) for( int n=ZERO; n<AA; n++ ) { vec2 rr = vec2(float(m),float(n))/float(AA); vec2 p = (2.0*(fragCoord+rr)-iResolution.xy)/iResolution.y; float an = 1.87 - 0.04*(1.0-cos(0.5*iTime)); vec2 q = (fragCoord+rr)/iResolution.xy; vec3 ro = vec3(-0.4,0.2,0.0) + 2.2*vec3(cos(an),0.0,sin(an)); vec3 ta = vec3(-0.6,0.2,0.0); mat3 ca = setCamera( ro, ta ); vec3 rd = normalize( ca * vec3(p,-2.8) ); col += render( ro, rd, q ); } col /= float(AA*AA); #endif fragColor = vec4( col, 1.0 ); }
代码复制自：https://www.shadertoy.com/view/ld3Gz2
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