DXR相关

DXR相关"/>

DXR相关

Tips

DXR ray tracing tutorial中：

TraceRay(gRtScene,
RAY_FLAG_ACCEPT_FIRST_HIT_AND_END_SEARCH | RAY_FLAG_SKIP_CLOSEST_HIT_SHADER,
0xFF, 0, hitProgramCount, 0, rayAO, rayPayload);

We’re going to tell our ray to never run the closest-hit shader and to stop as soon as we find any intersection.
这里注意RAYFLAG可以设置为skip closest hit shader；在anyhit shader中只有通过alpha测试后才会得到有效的hit，才能结束search；整个过程中不会走closest hit shader，会走any hit shader，可能会走miss shader。这种设置可以在AO中发挥作用，具体看DXR ray tracing tutorial。

// What code is executed when our ray misses all geometry?
[shader("miss")]
void AoMiss(inout AORayPayload rayData)
{// Our ambient occlusion value is 1 if we hit nothing.rayData.aoValue = 1.0f;
}// What code is executed when our ray hits a potentially transparent surface?
[shader("anyhit")]
void AoAnyHit(inout AORayPayload rayData, BuiltInTriangleIntersectionAttributes attribs)
{// Is this a transparent part of the surface?  If so, ignore this hitif (alphaTestFails(attribs))IgnoreHit();
}