Collision Detection with Slopes

[AeoniX]

Hello there everyone,

Been messing around with MMF2 for awhile now and finally decided on making something worthwhile (in my eyes anyway). A platformer.

I'm currently redoing the engine for a Third time now. The first one was based off David N's fastloop tutorial on the main website. After leaving it for a long time, I came back and redid it, heavily modifying a "High Precision Movement Engine" by Retriever II (cleaning out the unused event and the like).

This time, I'm still using Retriever II's engine concept, but Slope Detection is still stumping me. The main issue is when I want to jump onto a slope, when the active player comes close to the slope, the player is moved down horizontally to make contact with the "floor". But in doing so it loses it's momentum and the horizontal movement is jerked.

Now the question, how do you treat slope detection? I added the second version of the engine so you can see for yourselves.
Test Engine v2

Of course in no way do I take any credit for the engine.

[LB]

You ought to take a look at the old game Zeb.

[AeoniX]

I hesitated at first to respond quickly, so I looked at Zeb more times, looking at the slope detection.

It's nice and fluid, but also isn't variable, which is something I need. Zeb only dealt with 2x1 slopes, but I plan on using 1x1 and 2x1 slopes as well. Seeing as the detectors where only detecting for one set of slopes it makes things simple and you can code directly the movement patterns. With the added slopes, I'd have to add more detectors (which would make things messy).

[DavidN]

I put up an example of how to add ramps to my tutorial's platform movement here - http://www.clickteam.com/epicenter/ubbthreads.php?ubb=showflat&Board=5&Number=52566

The theory for most of them is probably much the same.

[DistantJ]

I'd use the 'rotating slope detector' trick, where you have detectors which actually rotate position until they're both on the ground (if one is touching the ground, but the other isn't, rotate them until they both are, then rotate the rest of the detectors to go with them so that your wall and floor detectors etc don't get stuck in the slope)... But then handling the X & Y movement based on the multiple directions can start to become complicated...

It depends on how accurate you want your slopes to be. It's perfectly possible to use simple 45 degree slopes programmed and still have it function properly on all different angles of slope as it will alternate between them.

[AeoniX]

I've gutted out the Engine I modified before, and I'm still in the process of working out how it goes up different angles, apparently it has on the spot slope detection, meaning it will detect if its 1x2, 1x1 or 2x1 slopes and act accordingly. If anyone's interested I'll upload it. It's quite complex but it works exactly how I want/need it to.

Of course it's not my work, it's Retriever II's.