Vec3f RayTracer::traceRay(Ray &ray, float tmin, int bounces, float weight,
float indexOfRefraction, Hit &hit) const
{
//printf("当前已有光线：\n");
//RayTree::Print();
Vec3f canswer;
if (bounces > max_bounces)
return Vec3f(0.0f, 0.0f, 0.0f);
Camera *camera = sceneParser->getCamera();
Group *group = sceneParser->getGroup();
int num_lights = sceneParser->getNumLights();
Vec3f cambient = sceneParser->getAmbientLight();
//原来最后是这里出了问题，一旦碰到有转换的物体，那么hit带出来的值是
//转换后的视线看到的值，而非本来视线看到的值
//所以解决方案是：距离不变，根据距离重新计算焦点
if (group->intersect(ray, hit, tmin))//撞到了
{
if (is_view_ray)
{
RayTree::SetMainSegment(ray, 0, hit.getT());
is_view_ray = false;
}
Vec3f cobject = hit.getMaterial()->getDiffuseColor();
Vec3f hitPoint = hit.getIntersectionPoint();
//环境光部分
canswer = cambient * cobject;
Vec3f clight;//光的颜色
Vec3f light_dir;//指向光的方向
Vec3f normal_dir = hit.getNormal();//交点法线向量
float distolight;//距离光源的距离
for (int i = 0; i < num_lights; i++)
{
Light *light = sceneParser->getLight(i);
//light_dir : the direction to the light
// 该方法用于获得指向光的方向，光的颜色，和到达光的距离
// 第一个参数传递的是焦点信息
light->getIllumination(hitPoint, light_dir, clight, distolight);
Ray ray2(hitPoint, light_dir);
Vec3f init_normal(0, 0, 0);
Hit hit2(distolight, NULL, init_normal);
//阴影检测
if (shadow)
{
if (group->intersect(ray2, hit2, tmin)){
RayTree::AddShadowSegment(ray2, 0, hit2.getT());
continue;
}
RayTree::AddShadowSegment(ray2, 0, hit2.getT());
}
//cpixel = cambient * cobject + SUMi [ clamped(Li . N) * clighti * cobject ]
//返回局部光
canswer = canswer + hit.getMaterial()->Shade(ray, hit, light_dir, clight);
}
//printf("当前已有光线：\n");
//RayTree::Print();
//反射光
Material *material = hit.getMaterial();
Vec3f rc = material->getReflectiveColor();
if (rc.r() > 0 && rc.g() > 0 && rc.b() > 0)
{
Vec3f mirrorDir;
Vec3f incoming = ray.getDirection();
mirrorDir = mirrorDirection(normal_dir, incoming);
// The ray weight is simply multiplied by the magnitude of the reflected color
Ray ray3(hitPoint, mirrorDir);
Vec3f init_normal(0, 0, 0);
Hit hit3(distolight, NULL, init_normal);
//忘记乘以本身的反射光系数%…………
canswer += traceRay(ray3, tmin, bounces + 1, weight*rc.Length(), indexOfRefraction, hit3)*rc;
if (bounces + 1 < max_bounces)
RayTree::AddReflectedSegment(ray3, 0, hit3.getT());
}
//printf("当前已有光线：\n");
//RayTree::Print();
//从这里开始还都存在问题！！！！！
//折射光
Vec3f transmitted;
Vec3f tc = material->getTransparentColor();
float index = material->getIndexOfRefraction();
if (tc.r() > 0 && tc.g() > 0 && tc.b() > 0)
{
Vec3f init_normal(0, 0, 0);
Hit hit4(distolight, NULL, init_normal);
//在判断折射光的存在之后，要考虑光线的位置：物体内还是物体外
//这里根据normal和incoming的点积来判断
Vec3f incoming = ray.getDirection();
float judge = normal_dir.Dot3(incoming);
if (judge < 0)//光线在外
{
if (transmittedDirection(normal_dir, incoming, 1, index, transmitted))
{
Ray ray4(hitPoint, transmitted);
canswer += traceRay(ray4, tmin, bounces+1, weight*rc.Length(), index, hit4)*tc;
RayTree::AddTransmittedSegment(ray4, 0, hit4.getT());
}
}
else//光线在内
{
normal_dir.Negate();
if (transmittedDirection(normal_dir, incoming, index, 1, transmitted))
{
Ray ray4(hitPoint, transmitted);
canswer += traceRay(ray4, tmin, bounces+1, weight*rc.Length(), 1, hit4)*tc;
RayTree::AddTransmittedSegment(ray4, 0, hit4.getT());
}
}
}
//printf("当前已有光线：\n");
//RayTree::Print();
}
else
canswer = sceneParser->getBackgroundColor();
canswer.Clamp();
return canswer;
}
bool QBVHAccel::Intersect(const Ray *ray, RayHit *rayHit) const {
//------------------------------
// Prepare the ray for intersection
QuadRay ray4(*ray);
__m128 invDir[3];
invDir[0] = _mm_set1_ps(1.f / ray->d.x);
invDir[1] = _mm_set1_ps(1.f / ray->d.y);
invDir[2] = _mm_set1_ps(1.f / ray->d.z);
int signs[3];
ray->GetDirectionSigns(signs);
//------------------------------
// Main loop
int todoNode = 0; // the index in the stack
int32_t nodeStack[64];
nodeStack[0] = 0; // first node to handle: root node
while (todoNode >= 0) {
// Leaves are identified by a negative index
if (!QBVHNode::IsLeaf(nodeStack[todoNode])) {
QBVHNode &node = nodes[nodeStack[todoNode]];
--todoNode;
// It is quite strange but checking here for empty nodes slows down the rendering
const int32_t visit = node.BBoxIntersect(ray4, invDir, signs);
switch (visit) {
case (0x1 | 0x0 | 0x0 | 0x0):
nodeStack[++todoNode] = node.children[0];
break;
case (0x0 | 0x2 | 0x0 | 0x0):
nodeStack[++todoNode] = node.children[1];
break;
case (0x1 | 0x2 | 0x0 | 0x0):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[1];
break;
case (0x0 | 0x0 | 0x4 | 0x0):
nodeStack[++todoNode] = node.children[2];
break;
case (0x1 | 0x0 | 0x4 | 0x0):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[2];
break;
case (0x0 | 0x2 | 0x4 | 0x0):
nodeStack[++todoNode] = node.children[1];
nodeStack[++todoNode] = node.children[2];
break;
case (0x1 | 0x2 | 0x4 | 0x0):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[1];
nodeStack[++todoNode] = node.children[2];
break;
case (0x0 | 0x0 | 0x0 | 0x8):
nodeStack[++todoNode] = node.children[3];
break;
case (0x1 | 0x0 | 0x0 | 0x8):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[3];
break;
case (0x0 | 0x2 | 0x0 | 0x8):
nodeStack[++todoNode] = node.children[1];
nodeStack[++todoNode] = node.children[3];
break;
case (0x1 | 0x2 | 0x0 | 0x8):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[1];
nodeStack[++todoNode] = node.children[3];
break;
case (0x0 | 0x0 | 0x4 | 0x8):
nodeStack[++todoNode] = node.children[2];
nodeStack[++todoNode] = node.children[3];
break;
case (0x1 | 0x0 | 0x4 | 0x8):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[2];
nodeStack[++todoNode] = node.children[3];
break;
case (0x0 | 0x2 | 0x4 | 0x8):
nodeStack[++todoNode] = node.children[1];
nodeStack[++todoNode] = node.children[2];
nodeStack[++todoNode] = node.children[3];
break;
case (0x1 | 0x2 | 0x4 | 0x8):
nodeStack[++todoNode] = node.children[0];
nodeStack[++todoNode] = node.children[1];
nodeStack[++todoNode] = node.children[2];
nodeStack[++todoNode] = node.children[3];
break;
}
} else {
//----------------------
// It is a leaf,
// all the informations are encoded in the index
const int32_t leafData = nodeStack[todoNode];
--todoNode;
if (QBVHNode::IsEmpty(leafData))
continue;
// Perform intersection
const u_int nbQuadPrimitives = QBVHNode::NbQuadPrimitives(leafData);
const u_int offset = QBVHNode::FirstQuadIndex(leafData);
for (u_int primNumber = offset; primNumber < (offset
+ nbQuadPrimitives); ++primNumber)
prims[primNumber].Intersect(ray4, *ray, rayHit);
}//end of the else
}
return !rayHit->Miss();
}
