#include "M:/vsfx419/shader_src/LightingUtils.h"
surface
carrust(float      Kd = .1,       /* basic brightness for carpaint    */
					kd2 = .8,     /* basic brightness for rust */
					Ka = 1,
                    Ks = 0.6,       /* hilite brightness     */
                    subKa = 1,      /* ditto sub-surf        */
                    subKd = .5,    /* ditto sub-surf        */
                    subKs = 0.7,    /* ditto sub-surf        */
                    Km = .1,         /* sub-surf bumpiness    */
                    Kenv = .1,       /* environ contribution  */
                    Ktop = 0.5,     /* scales the top color  */
					bumpvar = .1,
                    Ksub = 0.5,     /* scales the sub color  */
					min = 0.1,
					max = 0.5,
					rustedge = 0, /* intensity of hole */
					layerblend = .97; /* edge blend for rust */
            color   hicolor = 1,    /* top hilite color      */
                    locolor = 1,    /* sub-surf hilite color */
                    subCs = 1,      /* sub-surf color       */
					c1 = (0.0,0.070,0.576),	/* color 1 */
					c2 = (0.015,0.035,0.231),	/* color 2 */
					c3 = (0.015,0.0,0.156),	/* color 3 */
					lt_rust = color(0.705,0.447,0.192),
					dk_rust = color(0.313,0.086,0.047);
            string  envname = "",
					texname = "",
                    envspace = "world")
{
float layer = texture(texname[3]);
float redchan = texture(texname[0]),
greenchan = texture(texname[1]),
bluechan =  texture(texname[2]),
crackchan = texture(texname[3]);


//######CARPAINT LAYER
if (layer != 1){

vector Nnorm = normalize(N);
vector Inorm = normalize(I);
vector myVector = (1,0,0);
vector myCamera = transform ("object", "camera", myVector);

point   oldP = P;
normal  oldN = N;

Oi = Os;

color envcolor = envmapping(N, I, envname, envspace, Kenv);
color  topcolor = plastic(N, I, 0, Kd, 
                             Ks, 0.1, hicolor) * Ktop;
color fakecolor = (spline((1-abs(Nnorm.Inorm)),c1,c2,c3));

float  hump = (noise(s * 550, t * 550)*bumpvar);

P = P - hump * normalize(N) * Km;
N = calculatenormal(P);

color subCs =(mix(c1, c3, (1-abs(Nnorm.Inorm)))) ;
color  sublight = plastic(N, I, subKa, subKd, 
                            subKs, 0.1, locolor) * Ksub;
color  subcolor = sublight * subCs;

P = oldP;
N = oldN;

Ci = Oi * Cs*(subcolor + topcolor + envcolor);

}




color firstsurf=Ci*layerblend;




//########RUST LAYER
if (texture(texname) > rustedge){
normal	nf, n;
color	ambientcolor, 
		diffusecolor;
n = normalize(N);
nf = faceforward(n, I);
color surfcolor = 1;
Oi = Os;
ambientcolor = Ka * ambient();
diffusecolor = kd2 * diffuse(nf);

if(texname != "")
{

float blend = smoothstep(min,max,redchan);


float redc = (100-(redchan*100))/100+.2;
float greenc = (100-(redchan*100))/220;
if(redchan > rustedge)
surfcolor = ((redc*.8), greenc,0);

surfcolor = (mix((firstsurf), surfcolor, blend))*.8;

Ci = Oi * Cs * surfcolor * (ambientcolor + diffusecolor);
}
}

//#### DROP OPACITY WHEN GREEN, ADD CRACKS TO CHANNEL 4
if(crackchan > .2)
	Ci = mix(color(0.294,0.294,0.294),Ci,.2);
if(greenchan > .05)
	Ci = (Os*0);

}