You can use the function called CG_trace but you must reverse it first.
option two. Using the sentry visibility function will only work 180 Degrees
Code:bool Math::CEnginemath::IsVisible( centity_t * pEnt ) { _asm mov esi, pEnt; _asm xor edi, edi; _asm mov eax, 0x005881E0; //alterIW _asm call eax; }