Retrieve real distance from depth buffer for shadow ray (vulkan hybrid rendering)
Thanks for your help, I fixed it by changing the way i am computing the depth :)

const double z_b = texture(depthBuffer, texcoord).x;
const vec4 clipSpacePosition = vec4(texcoord * 2.0 - 1.0, z_b, 1.0);
vec4 viewSpacePosition = cam.projInverse * clipSpacePosition;
viewSpacePosition /= viewSpacePosition.w;
float depth = length(viewSpacePosition.xyz);