In OptiX < 7 there was a function called “rtIntersectionDistance” to get the current “t hit” value of the ray, which was very useful especially for volumes. But I found no “optixIntersectionDistance” function for that functionality in the OptiX 7.0.0 SDK.
Of course it would be possible to calculate that value again in the kernel, but that would create some time+memory overhead, since the t_hit value is already present internally. And it would need an expensive additional square-root instruction.
In the SDK examples for intersection programs I found optixGetRayTmin() and optixGetRayTmax(), but they are not returning the current “t_hit” value. Please tell me how obtaining “t hit” should be done in OptiX 7.