Pardon my ignorance on this topic, I really haven't dove deep into the inner workings of both the Source engine and the demo itself
Me and a friend have been talking about how to recreate the engine seen in the Siggraph 2000 demo.
Here is some bulletpoints from that, with some added by me.
Ultimately, this would have to be made in Xash3D due to the limitations of GoldSrc
- Displacements
- VTF Support (something that isn't wads)
- A basic physics engine (edit: it seems like only brushes supported physics, and there was no collision for the player nor displacements)
- Maybe port the 2003-2024 steam ui since the 1998 bitmap seems to be designed for it
- The texturing effects, probably coming from the VTF system
- The 'bounding box' NPC interactions?
I'll list more later but this is just for someone to see it and attempt it, because we both do not have C or C++ knowledge.