I was wondering if it might be a good idea to have a L4D1 plugin that modifies the Molotov to have a similar effect to the bile bomb in L4D2. When thrown, the modified Molotov (or bile-molly) would reveal the position of any Infected with a halo glow effect, so that when any of them entered the flames on the ground the players would see them become highlighted through the flames and even reveal them when hidden behind objects that would normally obscure the player's view - such as walls or fences etc - giving players the temporary "x-ray vision" effect as already used in L4D2.
To provide us with a narrative as a gameplay mechanic for L4D1, the 'bile-flame' damage of the bile-Molotov could be made weaker than a normal Molotov (due to the bile goo diluting the petrol fuel in the bottle to be less effective, ofc its main purpose is to create a sticky fluorescence to highlight those nasty Infected that would normally be lurking or hiding away outside of the player's view. In addition, the normal molly could still burn itself out at the default time (15 seconds), but the bile-molly burnout time could be doubled, but as a tradeoff, let it have a damage factor of perhaps half of that of the normal molly.
Players could then choose between using the normal Molotov or the weaker bile-Molotov, however, it would also need to include a chat command -!bilemolly- that toggles this feature on or off, or alternately use a trigger action such as throw the Molly while also pressing the [USE] key. It could also be useful to have CVAR options to add the glow effects to either Infected or players or both, with even an option to have the highlighted glow effect using a colour that contrasts with the orange flames of the Molotov - such as blue for example (again set as a CVAR).
In image link 1 below for example, the bile-Molotov would highlight survivors and infected within the player's field of view, as well as highlighting them from behind the vehicle. The different coloured glows around the characters in the image is just for illustration purposes, but a blue colour would likely contrast well with the orangeness of the flames.
[Link 1 image]
In image 2 below it shows how the bile bomb splash effect in L4D2 reveals the positions of the Infected lurking behind the building wall, giving the player a temporary 'x-ray vision' and a heads-up point of view.
[Link 2 image]
Anyway, I hope this suggestion for a modified Molotov for L4D1 could be useful to players and add an interesting new feature to the game. I shall live in hope that some creative coder here may find this idea an interesting challenge. If not, then at least I tried.
Thanks for reading,
Sunyata