QUOTE (onlyghostdanceswhiledrunk @ Mar 26 2012, 04:46 AM)
pg.201 SR4:
"Single-Sense illusions affect only one sense. Full Sensory illusions affect all senses...... Physical Illusions: Physical illusion spells create actual images or alter physical properties such as light or sound
The observer must generate more hits than the spellcaster to determine that the illusion is not real. If the spell is not completely resist, the character is fully affected by the illusion.
Pg. 202 SR4:
These area spells creat illusions of any object, creature or scene the caster desires. They can create an illusion of anything the caster has seen before, from a flower or a credstick to a dragon breathing fire, as long as the illusion is no larger than the spells area.... Trid Phantasm affects technological sensors as well.
The description says all senses (unlike the very acute description in improved invisibility. Hence you are quite easily able to do what you will with it as it actually changes the properties that are perceived by the viewer (ie a boquet of flowers that is cast over an hmg will not respond to MAD scanners etc cause it changes the properties).
I see nothing in what you have described that contradicts me, in fact it is explicitly what I said you could do.
It does not say you can erase an existing sense although you can cover it up: you can't silence a gunshot but you can make a car crash sound to cover it up; you can't make your sidearm invisible but you can make it look like a bouquet of flowers.
Text on Street Magic page 163:
Illusions that hide or conceal rather than creating sensory input—such as Invisibility—are harder, and so receive a specific Drain modifier.
Table on Street Magic page 163:
Illusion Spells
Obvious –1
Realistic +0
Multi-Sense +0
Single-Sense –2
Illusion Hides or Conceals +2
Trid Phantasm spell description from SR4A page 209:
These area spells create convincing illusions of any object, creature, or scene the caster desires. They can create an illusion of anything the caster has seen before, from a flower or a credstick to a dragon breathing fire, as long as the illusion is no larger than the spell’s area.
This description fits with the "add anything" interpretation include an illusion of a wall to hide behind. It does not mention anything resembling invisibility/hush/silence/etc.
Trid phantasm: physical (drain +1); multi-sensory (+0); realistic (+0); LOS target (+0); area (+2) = F/2 +3 drain as listed in the spell description.