I'm looking for explanations, links to a tutorial, anything that can explain the process of making these two things:

1> Underground-style counters: I am making a map with a trigger that activates every time something passes through it, and so I need a counter to count how many times an object has gone through it (this will be happening with a lot of objects at high speeds) I found the textures for the countdown clock used during the giant door scene, but neither an env_texture_toggle nor a material_modify_control would get the texture to count.

2> Flowing gel: I know the entity to spray paint is (aptly) an info_paint_sprayer, but I need it to flow through a tube, like the paint in the latter parts of P2 before you break the tubes with bombs (I don't need to know how to break it, seems pretty simple, but I wouldn't mind a tutorial on that, too.)

I think the better thing to know how to do this things is decompile originals maps from valve. You will know the best way, so its hard to find it in valve maps if you are not advanced mapper.

AntiVector wrote:
2> Flowing gel: I know the entity to spray paint is (aptly) an info_paint_sprayer, but I need it to flow through a tube, like the paint in the latter parts of P2 before you break the tubes with bombs (I don't need to know how to break it, seems pretty simple, but I wouldn't mind a tutorial on that, too.)

Never used it before but i know it's a particle effect...

So just search on how to use particle effects and choose the right effect here:

http://developer.valvesoftware.com/wiki ... _Particles