Question: We use a semitransparent grid layer (.mig file) to show 'hotspot' intensity in MapBasic (MapInfo). Because the grid is just a rectangle, this looks ugly. See for instance:
![Hotspot example](https://i.stack.imgur.com/kUQO4.png).

Now MapInfo allows grid cells to be invisible (NULL), which would result in round-like hotspot regions.  

But we would prefer to extend the grid. Of course we could just add extra rows and columns, but that would require a lot of extra memory. And it would still show a boundary at some zoom level.

Is it possible to infinitely extend a grid layer with a constant value?

Answer: 
I dived a bit more into it.

We use MIGrid.dll. I found one (old) [reference](http://georezo.net/jparis/mb_r/doc/migrid_MB_calls/GE_MB_calls.pdf "MIGrid MapBasic calls").

A grid is mapped to a rectangular region (GE\_GRID\_INFO stuct). Every cell has equal size. So I'm afraid it's just impossible with grids.

If anyone knows of a workable alternative, using MapInfo...
<http://acidmaps.org> 

the good thing is it integrates with Geoserver. Geoserver is the GIS server of choice at vtsPN. Since I am involved with Sherpa now, I might be able to pull a few strings ;-)