when attempting render plane in image, whole image being phong shaded. see plane. pass array of primitives checkforintersection function. tmin set 100, if intersection found changes. if intersection found , tmin changes cast shadow rays. works spheres, when try implement plane, whole image/background gets phong shaded.
why whole background being phong shaded. there wrong plane intersection formula?
when tmin line commented: http://imgur.com/k789dp4
when tmin line uncommented: http://imgur.com/sbyxhex
neither show me plane. although when set plane cutting spheres in half, show cut in ambient color.
// ********** global variables ********* rgbimage * myimage; vec3 neye(0.0,0.0,-5.0); vec3 lightsource1(-2.0,-1.5,0.0); vec3 lightsource2(0.0,-2.0,0.0); float tmin=100.0; struct prim { vec3 origin; double radius; double undersquare; vec3 ambient; vec3 diffuse_albedo; vec3 specular_albedo; float specular_power; vec3 light_intensity; vec3 normal; vec3 pt1; vec3 pt2; vec3 pt3; }; // *****************check intersection************** prim checkforintersection(vec3 point, vec3 directionvector, prim prims[4], bool printit){ prim pickprim; float d = 0; float denom = dot(prims[3].normal, directionvector); //is correct direction vector? float numer = dot(prims[3].normal, neye) + d; //vec3 hittemp; //vec3 hitpoint; if (denom!=0){ float t= -(numer) / denom; //cout << t << endl; if (t <= tmin && t>0.001 && t<6){ //tmin=t; pickprim = prims[3]; } } return pickprim; } // ***********************calling function********************** prim sphere1; prim sphere2; prim sphere3; prim pickprim; ray shadowray; ray shadowray2; tmin = 100; vec3 pixelcolor(0,0,1); prim squareplane; squareplane.ambient=vec3(0.329412, 0.223529, 0.027451); squareplane.diffuse_albedo=vec3(0.780392, 0.568627, 0.113725); squareplane.specular_albedo = vec3(0.992157,0.941176,0.807843); squareplane.specular_power = 27.8974; squareplane.light_intensity = vec3(1,1,1); squareplane.normal = normalize(vec3(0,0,-0.1)); prim prims[4] = { sphere1, sphere2, sphere3, squareplane }; pickprim = checkforintersection(neye, nvecdir, prims, false); // last parameter print debugging if (tmin != 100){ //if tmin has changed, found , intersection, send shadow ray vec3 hittemp(nvecdir.x*tmin, nvecdir.y*tmin, nvecdir.z*tmin); vec3 hitpoint = (neye + hittemp); shadowray.vecdir = (normalize(lightsource1 - (hitpoint))); //shadowray2.vecdir = (normalize(lightsource2 - (hitpoint))); tmin = 100; // set tmin new ray trace. prim tmindummy = checkforintersection(hitpoint, shadowray.vecdir, prims, true); if (tmin != 100){ //if tmin not equal 100, found intersection, point in shadow, return ambient. pixelcolor = pickprim.ambient; return pixelcolor; } else{ pickprim.normal = hitpoint - pickprim.origin; pixelcolor = implementphong(pickprim,neye,hitpoint); //pixelcolor = vec3(0,1,0); return pixelcolor; } } else{ return pixelcolor; } }
