示例#1
0
        public bool hit(ray r, float t_min, float t_max, hit_record rec)
        {
            vec3  oc           = r.Origin - center;
            float a            = vec3.dot(r.Direction, r.Direction);
            float b            = vec3.dot(oc, r.Direction);
            float c            = vec3.dot(oc, oc) - radius * radius;
            float discriminant = b * b - a * c;

            if (discriminant > 0)
            {
                float temp = (-b - (float)Math.Sqrt(discriminant)) / a;
                if (temp < t_max && temp > t_min)
                {
                    rec.t      = temp;
                    rec.p      = r.point_at_parameter(rec.t);
                    rec.normal = (rec.p - center) / radius;
                    return(true);
                }
                temp = (-b + (float)Math.Sqrt(discriminant)) / a;
                if (temp < t_max && temp > t_min)
                {
                    rec.t      = temp;
                    rec.p      = r.point_at_parameter(rec.t);
                    rec.normal = (rec.p - center) / radius;
                    return(true);
                }
            }
            return(false);
        }
        public bool hit(ray r, float t_min, float t_max, hit_record rec)
        {
            hit_record temp_rec       = new hit_record();
            bool       hit_anything   = false;
            double     closest_so_far = t_max;

            for (int i = 0; i < list_size; i++)
            {
                if (list[i].hit(r, t_min, (float)closest_so_far, temp_rec))
                {
                    hit_anything   = true;
                    closest_so_far = temp_rec.t;
                    rec            = temp_rec;
                }
            }
            return(hit_anything);
        }
示例#3
0
        static vec3 GetColor(ray r, hitable world)
        {
            hit_record rec = new hit_record();

            //float value = -1;
            //bool hit = HitSphere(new vec3(0, 0, -1), 0.5f, r, out value);
            if (world.hit(r, 0.0f, float.MaxValue, rec))
            {
                return(new vec3(1 + rec.normal.x, 1 + rec.normal.y, 1 + rec.normal.z) * 0.5f); //[-1,1]-->[0,2]-->[0,1]
            }
            else
            {
                vec3 Normal = (r.point_at_parameter(value) - new vec3(0, 0, -1)).Normalize(); //normal:[-1,1]
                return(new vec3(1 + Normal.x, 1 + Normal.y, 1 + Normal.z) * 0.5f);            //[-1,1]-->[0,2]-->[0,1]
            }

            vec3  normalizedDir = r.Direction.Normalize();
            float y             = normalizedDir.y + 1;     //[-1,1]-->[0,2]
            float t             = 0.5f * y;                //[0,2]-->[0,1]
            vec3  color_start   = new vec3(1, 1, 1);       //white
            vec3  color_end     = new vec3(0.5f, 0.7f, 1); //light blue

            return(color_start * (1 - t) + color_end * t); //linear interpolate
        }