Fill & Wireframe in the same time

I’m using OpenGL+Delphi and I want to draw an filled object but in the same time to draw its wireframe structure over. The problem is that if I do something like this:

drawSolid
scale the Object; // Add a small offset
drawWire;

some of the wire triangles are not visibile

I understand that i should use Polygon Offset but I dont know how.(some sample code pretty much expected)

Do i have to take into account the geometry for computing the Offset values?

I deal with CONCAVE objects so drawing solid+setting depth testing off+drawing wire will not do the trick>

Thanks,
Clau

as u said use polygon offset
v easy to use (seacrch google or see redbook for exact syntax)

draw solid model
enable polygon offset of perhaps (1,1)
draw wire model

There’s a good explanation of PolygonOffset in the FAQ . Read through all of it while you’re at it, it contains lots of things that are worth knowing.