But it almost CAN'T walk on the heightmap terrain. It always get stuck and if I scale the "collisionsphere" up, it works a little better, but it makes the character fly in the air.
How can I fix this?
Your in luck because I was just testing collisions with the irrlicht methods. Your problem is your level is scaled very small which is not a bad thing just need to compensate for it. Depending on how small your level is scaled you will need to make the ellipsoid smaller and smaller until you get the results you want. You said that making
smaller that it improved results right? Then just keep going small try .5, then .05 and so on until you get the results that are best for your map. Also might want to place ur node up a little bit as indicated by the third vector3df function argument. How is the gravity scaled? Can you jump? Try it and see how fast you fall, my bet is it is very rapid descent.