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• uint32_t private0[5]: Data reserved for internal use.
• float opacityThreshold: Accumulated opacity along this ray, updated for each presence hitOpacity threshold associated with the ray. Used for better-stratified presence.
• mutable uint16_t hitId: Internal hit id.
• uint16_t flags: Internal flags.
• uint16_t wavelength: Ray wavelength. Can be retrieved by using RixShadingContext::GetBuiltinVar(k_wavelength, ...).

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