Gravity on a Mesh Terrain

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Sledge

Unfortunately it's still shaking abit when you stand still on an almost-flat slope... Is there a better way to simulate 1st person player gravity and air acceleration?

Here's a simplified (in that you'll have to build your original control scheme/mouselook back in... curs keys only from me!) model that won't shake but will simulate gravitational acceleration along the y axis (toddle off the edge to see)...

Open in online IDE

Const TERMINAL_Y_VELOCITY#=2.0
Const TERRAIN_SIZE=16
Const TERRAIN_SCALE=8

Const PLAYER_GEOMETRY=1
Const LEVEL_GEOMETRY=2

Graphics3D 800,600,0,2
SetBuffer BackBuffer()
cam=CreateCamera(): PositionEntity cam,(TERRAIN_SIZE*.5)-1,10,-TERRAIN_SIZE
light=CreateLight(1,cam): PositionEntity light,40,40,-40
worldPiv=CreatePivot(): PositionEntity worldPiv,(TERRAIN_SIZE*.5),0,(TERRAIN_SIZE*.5)

terrain=CreateTerrain(TERRAIN_SIZE)
ScaleEntity terrain,TERRAIN_SCALE,TERRAIN_SCALE/2,TERRAIN_SCALE
TerrainShading terrain,True
For x=0 To TERRAIN_SIZE-1
For z=0 To TERRAIN_SIZE-1
	ModifyTerrain terrain,x,z,Rnd(1,10)
Next
Next

terrainTex=CreateTexture(64,64)
Color 50,100,50
Rect 0,0,64,64,True
Color 70,140,70
For x=0 To 127
	Plot Rand(0,63),Rand(0,63)
Next
CopyRect 0,0,64,64,0,0,BackBuffer(),TextureBuffer(terrainTex)
EntityTexture terrain,terrainTex,0,0



Type player
	Field model
	Field gravityY#
	Field incGravity
End Type
currentPlayer.player=Null

currentPlayer=New player
currentPlayer\model=CreateCube()
currentPlayer\gravityY=0.0
currentPlayer\incGravity=True
PositionEntity currentPlayer\model,(TERRAIN_SIZE/2)*TERRAIN_SCALE,50,(TERRAIN_SIZE/2)*TERRAIN_SCALE
EntityType currentPlayer\model,PLAYER_GEOMETRY : EntityType terrain,LEVEL_GEOMETRY

Collisions PLAYER_GEOMETRY,LEVEL_GEOMETRY,2,2




While Not KeyHit(1)
	
	If KeyDown(203) Then TurnEntity currentPlayer\model,0, 1,0
	If KeyDown(205) Then TurnEntity currentPlayer\model,0,-1,0
	If KeyDown(200) And currentPlayer\incGravity=False Then MoveEntity currentPlayer\model,0,0,.1
	If KeyDown(208) And currentPlayer\incGravity=False Then MoveEntity currentPlayer\model,0,0,-.1
	
	
	
	If currentPlayer\incGravity=True
		currentPlayer\gravityY#=currentPlayer\gravityY#+.02
		If currentPlayer\gravityY#>TERMINAL_Y_VELOCITY Then currentPlayer\gravityY#=TERMINAL_Y_VELOCITY
	EndIf	
	TranslateEntity currentPlayer\model,0,-currentPlayer\gravityY#-.1,0 : UpdateWorld
	If EntityY(currentPlayer\model)<-50 Then PositionEntity currentPlayer\model,(TERRAIN_SIZE/2)*TERRAIN_SCALE,50,(TERRAIN_SIZE/2)*TERRAIN_SCALE
	PointEntity cam,currentPlayer\model: RenderWorld :	Flip
	
	For currentCollision=0 To CountCollisions(currentPlayer\model)
		If currentCollision>0
			If GetEntityType(CollisionEntity(currentPlayer\model,currentCollision))=LEVEL_GEOMETRY
				currentPlayer\gravityY=0
				currentPlayer\incGravity=False
			EndIf
		Else
				currentPlayer\incGravity=True
		EndIf
	Next
Wend

Now if you want inertia along with that, that's another system and should be handled separately I think. I notice in your original that you apply air acceleration to cx and cz... I would restrict it to affecting y.

Also, if you want the player to slide only at certain (extreme) inclines then that will involve a 'pick' downwards, interpreting the vector of the 'picked' geometry and setting the collision rules accordingly (sliding or not). I have only concentrated on the shaking issue.