From the 3.0 FAQ (if desired):
"Note that the antimagic field blocks line of effect, so an area cannot extend through the antimagic field."
Also, from the Rules of the Game:
"When a spell is aimed into an area of antimagic from somewhere outside the area, the antimagic blocks line of effect for the spell"
and
"An antimagic effect also blocks line of effect (see Chapter 10 in the Player's Handbook) for any magical ability, though a creature always has line of effect to itself. So a creature with a spell-like ability could use the ability on itself, even in an antimagic field. The magic still would be suppressed while the creature remains inside the antimagic effect, and the creature would gain no benefit from the ability until it left the area of antimagic."
and
"The rules don't tell you what to do when whatever blocks the spread's line of effect isn't a solid object (for example, an antimagic field). In this case, just the treat the antimagic field like a solid obstacle."
and
"some things that you can see through can block line of effect, such as a wall of force or an antimagic field. "
"Note that the antimagic field blocks line of effect, so an area cannot extend through the antimagic field."
Also, from the Rules of the Game:
"When a spell is aimed into an area of antimagic from somewhere outside the area, the antimagic blocks line of effect for the spell"
and
"An antimagic effect also blocks line of effect (see Chapter 10 in the Player's Handbook) for any magical ability, though a creature always has line of effect to itself. So a creature with a spell-like ability could use the ability on itself, even in an antimagic field. The magic still would be suppressed while the creature remains inside the antimagic effect, and the creature would gain no benefit from the ability until it left the area of antimagic."
and
"The rules don't tell you what to do when whatever blocks the spread's line of effect isn't a solid object (for example, an antimagic field). In this case, just the treat the antimagic field like a solid obstacle."
and
"some things that you can see through can block line of effect, such as a wall of force or an antimagic field. "