Upon moving to 5.4 any material opacity mask setting for foliage that isn’t a constant 1 causes foliage to disappear when too close to camera. Interestingly this distance is different for different assets that share the same masked material. Note that this arbitrary distance is quite far, making most nanite enabled foliage in a scene appear bare.
Things I have ruled out:
Changing r.Nanite.MaxPixelsPerEdge 0.5
Setting r.Nanite.MaxNodes 200000
after checking stat RHI to get a triangle value
Changing the opacity mask clip value to pretty much anything between 0 and 1, even very small values.
None of these change the amount or distance from the camera that nanite eliminates the material from view. It is always close to the camera that to asset disappears, not far away, and always only appears when nanite is enabled. The material graph does not show the behavior, and what mask is placed into the opacity mask node is irrelevant, any non-constant exhibits the effect.
Here is the effect on different nanite enabled foliage assets. Note the different distances it appears.
