Miss shader is always triggered, and closest-hit is never triggered

I am learning to build a ray tracing pipeline. however, the generated ray is always missed even when I use negative normal as ray direction. I checked my ray tracing pipeline in Nsight Graphics, I can not found any wrong item. This problem is stucking me for a long time, is anyone able to find something what I did wrong?

  • payload struct
struct hitPayload
    vec2 HitInfo;
  • ray generation shader
layout(location = 0) rayPayloadEXT hitPayload hitLoad;

layout(binding = 0, rgba8) uniform image2D uWorldNormalImage;
layout(binding = 1, r8) uniform image2D uAoImage;                // Output AO image
layout(binding = 2) uniform accelerationStructureEXT scene;     // Built AS
layout(binding = 3, rgba32f) uniform image2D uWorldPositonImage;

void main()
    ivec2 size = imageSize(uAoImage);
    ivec2 pixel = ivec2(gl_LaunchIDEXT.xy);
    vec3 worldPos = imageLoad(uWorldPositonImage, pixel).xyz;
    if(worldPos == vec3(0.0)){
    vec3 normal = imageLoad(uWorldNormalImage, pixel).xyz;
    normal = normalize(normal*2.0 - 1.0);
    vec3 direction = -normal;
    hitLoad.HitInfo = vec2(0.0);
        scene,      // Acceleration structure
        0xFF,       // 8-bit instance mask
        0,          // SBT record offset
        0,          // SBT record stride for offset
        0,          // Miss index
        worldPos,   // Ray origin
        0.0,        // Minimun t-value
        direction,  // Ray direction
        1000.0,     // Maximum t-value
        0           // Location of payload
    imageStore(uAoImage, pixel, vec4(hitLoad.HitInfo.y));

  • closest hit shader
layout(location = 0) rayPayloadInEXT hitPayload hitLoad;

void main()
    hitLoad.HitInfo[1] = 1.0;
  • miss shader
layout(location = 0) rayPayloadInEXT hitPayload hitLoad;

void main()
    hitLoad.HitInfo[0] = 1.0;

The above code should always trigger hit, but the uAoImage is always black.

The below screenshots are from Nsight graphics, I can not find any abnormal thing.

I found a weird thing

I use Nsight graphics to caputre C++ replay, and the closest-hit is triggered in replay capture. The below screen shot is the uAoImage in replay capture.

In my native code, I didn’t have the middle revision of uAoImage.

I found the reason casuing this issue. I did not waitting for finishing the command of building acceleration structure.

But there is no validation error for this issue, and normal representation of acceleration structure in Nsight graphics keeps me from noticing the issue exsiting in building acceleration structure.

It’s been a long struggle to get to this point, so many tears in my face.

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