HDTP is not about adding stuff to DX. It's about recreating the old stuff with more detail. The position of the dividing line is widely debated on these forums, I know, but personally I think making weapon mods visible would fall under the category of added detail rather than actual large changes.
Also, it would kick ass.
For those of you who are not modding savvy, here's the only way I know to do it, there may be a better and easier way that I haven't thought of:
- Add a silencer and a scope to the model of every weapon that is supposed to have an option for those mods.
- Make sure the silencer and the scope use seperate textures from the rest of the weapon when you UV map it.
- Code up the weapon so it starts with the silencer and the scope being invisible.
- Code up the weapon so when you add a silencer mod, the weapon will switch to using the silencer texture for the silencer instead of a transparent texture.
- Do likewise for the scope.