Normal map shrinking problem

[system]

I sculpted a object from plane with open boundary

And try to extract the normal map with smooth UV option,

but the outline of the map shrink like picture I upload.

If I turn off the smooth UV option, the shrinking problem solve.

but normal map get awkward edges.

How can I get a map with not ony right size boundary but also smooth surface?

I use Zbrush 3.5r3

[aurick]

1) That’s exactly what SmoothUV does. However, have you checked to see if it’s an issue in your rendering engine?

2. Why are you still using 3.5 when version 4 was a free upgrade?