sliding up surfaces at high velocity

when approaching a slanted brush at high velocity (which depends on the angle of the brush,
closer to flat usually means higher velocity required), other source engine games like cs:s, tf2, lfd etc have a thing where you can slide up
and glide across the brush. in gmod13 you just hit the brush and come to a complete stop, as though it is a completely flat brush.

this is a long shot, but does anyone know why this happens? it is kind of crucial for my gamemode to work well!

http://puu.sh/1ty1r

( complete stop at the end, where in cs:s it would slide up. )

I think it’s a console command.

I tried loading a complete list of every default cs:s cvar and it didn’t fix it :v

maybe it’s just disabled in garry’s mod by default?

sv_sticktoground 0