Raster to TIN Display Problems

[DonaldSmith]

Hello.  I'm running ArcScene 10.7.1.  Trying to create a TIN from an SRTM raster file, so I can lay a DOQ over the TIN.

When I use the "Raster to TIN" tool, the TIN created---but all I see is a set of colored lines.  The TIN layer does not display properly.  

[DonaldSmith]

Here's another screenshot.  You can see the input data set (an SRTM file) and the "finished" TIN.