...and remember, only the face of the hint brush that you want a PV split to appear on should be textured with hint, the other faces should be textured in hintskip. If it's not there, or it's broken, then add the following to your common.shader:
// ydnar: skip works like quake 2 hint: it doesn't generate bsp splits
// use on sides of hint brushes where you don't want bsp splits or portals
// add this to your common.shader file
textures/common/hintskip
{
qer_editorimage textures/common/skip.tga
qer_nocarve
qer_trans 0.30
surfaceparm nodraw
surfaceparm nonsolid
surfaceparm structural
surfaceparm trans
surfaceparm noimpact
surfaceparm skip
}
In Radiant, goto plugins -> prtview -> load prt file to see the vis portals once your map has compiled. If there is a huge number of portal volumes then change all unnecessarily structural brushes to detail brushes. Ctrl+D toggles the detail brush filter.