I am trying to learn how to create custom entities for hammer. In my quest, I have found this helpful looking site here: https://developer.valvesoftware.com/wik ... cal_Entity . This looks like it will be of much help. The problem is, it is telling me to add a source file to the solution, and I do not know where to find this solution. I've been searching for quite a while. Does anyone know where I can find this solution? For now, I'm going to move on and come back to this when I have more information.

Yeah, that site will be a huge help. It's an official site, but it is written mostly by the community. This can make it very reliable, as it comes from a variety of different sources, all of which who have experience in developing with the Source engine. Back on topic, though, I did not see any "solution," anyway. Neither did Ctrl+F. No results came up, so I'm guessing that means it wasn't there anyway. If it was, and you still see it, though, maybe it meant to say "Source File?"

Portal 2 doesn't really have very open developer tools, unlike half life 2. Creating custom entities isn't really possible with the limited tools we have.

What if you wrote it for HL2, then used the HL2 FGD in the P2AT? I don't have much experience in these things, so I doubt that would work, but could it?

No. You can add a custom entity to the FGD easily enough, but that doesn't mean the game will recognize it. Portal 2 is closed-source and it is thus impossible to add new entities.

Well these are some depressing replies. Alright, well thanks for all your help. Well, I'm sure there is another way to do what I'm trying to do, I was just choosing the hardest to help me learn. All I think I need for that is to find an entity that can ray-cast for me.

Hmmm... I really think that you can get pretty much anything, if not via an already existing entity, via vscripting... What do you need to achieve, if I may ask?

I'm trying to create a couple of reflection cubes that each change the color of the laser that is hitting it. Just yesterday, I tough myself how to create basic particle systems. So, my idea is that I can add a couple models of reflection cubes(Or just create a physbox if that doesn't work out), and raycast from the emitter model to the cube. If the cube is hit, then an attached info particle system can emit the color laser specific to the reflection cube. I want to raycast along that line aswell to test to see if it hits a laser receiver model. If it does, it runs an output. I just need to know how to raycast yet, unless there is something I'm not thinking of that could ruin everything which is always possible.

Complex and interesting.

If HMW managed to make the sendificator, I'm sure your idea can be also achieved by scripting

I cannot help here though, sry.

Look at the Sendificator script, it essentially rebuilds the code for the Discouragement Beam to make the green sending laser.

I just looked up this sendificator. It looks really cool. Where can I get the script for it?

Edit: I think I found it. Thanks.