FPSTEST and Stairs / Ramps

Blitz3D Forums/Blitz3D Programming/FPSTEST and Stairs / Ramps

GR (Posted 2004) [#1]

I am a bit confused. I am using Rob Cumming's FPSTEST with a level I have exported to B3D from Cartography Shop 4.1. I am able to walk around the level and the collision with various objects and the flooris working but stairs and ramps are not working at all. The player (camera) just stops when it enounetrs a ramp or stairs. The code used to check for steps and flooring is: ;steps and floor collisions pick=LinePick (EntityX(player),EntityY(player),EntityZ(player),0,-playerheight,0) If pick PositionEntity player,EntityX(player),PickedY()+playerheight#,EntityZ(player) vy=0 EndIf vy=vy-.2 vy=vy*0.9 HelP()

Jeremy Alessi (Posted 2004) [#2]

What sort of collision are you using for the player. I've noticed that if you aren't usine a sphere (or very close to a perfect sphere) that the players won't slide over tiny "rifts" in geometry. Of course also for stairs, each step must be smaller than the radius of the sphere.

GR (Posted 2004) [#3]

OKay, here is my sample project. Any advice is greatly appreciated! http://www.geocities.com/stevev4v/test.zip Use WASD to walk around. :) Thanks!

WolRon (Posted 2004) [#4]

vy=vy*0.9 Why are you making y velocity increasingly smaller(or am I reading that incorrectly?)?

GR (Posted 2004) [#5]

Not sure, as I said in my first post, this is a pared-down version of a demo released by Rob Cummings called FPSTEST. This version that is in my zip archive just has the shooting code removed as my game doesn't use any of that. I didn't develop this source and that is probably why I cannot understand why ramps and stairs do not work.

jfk EO-11110 (Posted 2004) [#6]

There are several methods you can use to implement gravity, and there are seeral examples, just like the on you mentioned. Personally I think this one is probably not the one with no complication. Maybe you better start with your very own system, so you always know what's going on. Try something like translateentity player,0,-.1,0 And of course, this is only a beginning, later you probably will use things like grav#=-.1 ... while gameloop if linepick(entityx(player),entityy(player),entityz(player),0,-player_height#,0)<> floor then translateentity player,0,grav#,0 if grav#>-1.5 then grav=grav*1.1 ; acceleration while falling else grav#=-.1 endif ... this way it will be easier to implement an independent jumping function, btw. An other thing is, sometimes your level design doesn't fit with the desired Player collision radius, eg. the steps of a stairway could be too big. In such a case I'd suggest not to waste too much time and simply put an invisible (entityalpha) quad onto the stairs, so it will become a ramp.

Rob (Posted 2004) [#7]

;a;fps level, graphics & code by rob cummings (rob@...) ;job offers welcome as always ; ;you may learn from this and use the code however you may not ;re-use graphics without permission. ;unoptimised clean code, minimal comments ;framerate variables Const FPS=85 Const debug=0 ;collision variables Global col_level=1,col_player=2,col_bullet=3 ;player variables Global pitch#,yaw#,mxspd#,myspd#,vx#,vy#,vz#,camera,player,gun,pick,gunsight,guntarget,hand ;other vars Global firetex,firetexpos#,bob#,target,scorchsprite,plasmasprite,shockwavesprite,recoil# Global cameraheight#=5 ;height of player eyes Global playerheight#=6 ;height of collision sphere Global playerradius#=3 ;radius of collision sphere xres=800:yres=600:depth=32:mode=1 Graphics3D xres,yres,depth,mode HidePointer ;setup camera=CreateCamera() CameraRange camera,0.2,400 CameraFogMode camera,0 ;hud tex=LoadTexture("target.png",2) TextureBlend tex,2 target=CreateSprite() EntityTexture target,tex EntityFX target,1 EntityOrder target,-1 EntityBlend target,3 EntityParent target,camera MoveEntity target,0,0,12 EntityAlpha target,0.8 ;player player=CreatePivot() hand=CreatePivot() EntityParent hand,camera MoveEntity hand,.8,-.8,.8 lite = CreateLight(1) ; change this to 2 or 3 to see different lights LightRange lite,15000 LightColor lite,255,255,255 ;level level=LoadAnimMesh("testlevel1.b3d") ;level collisions EntityType level,col_level,1 ScaleEntity level,.03,.03,.03 ;set up picking - this is because shooting and stair climbing needs pickable geometry. You can use picks for other stuff too ent = level ; specify your level While ent EntityPickMode ent,2 ent = NextChild(ent) Wend ;other collisions EntityType player,col_player EntityRadius player,playerradius,playerradius/2 Collisions col_player,col_level,2,2 PositionEntity player,0,10,0 PositionEntity level,0,0,0 ResetEntity player ;mainloop with standard timing code period=1000/FPS time=MilliSecs()-period While Not KeyHit(1) Repeat elapsed=MilliSecs()-time Until elapsed ticks=elapsed/period tween#=Float(elapsed Mod period)/Float(period) For k=1 To ticks time=time+period If k=ticks Then CaptureWorld ;basic game tasks UpdateWorld UpdatePlayer Next RenderWorld ;hit spacebar to save a screenshot If KeyHit(57) n=n+1 : SaveBuffer(BackBuffer(),n+".bmp") Flip Wend End Function UpdatePlayer() ;look mxspd=MouseXSpeed()*0.25 myspd=MouseYSpeed()*0.25 MoveMouse GraphicsWidth()/2,GraphicsHeight()/2 pitch=pitch+myspd yaw=yaw-mxspd If pitch<-90 Then pitch=-90 If pitch>90 Then pitch=90 RotateEntity camera,pitch,yaw,0 RotateEntity player,0,yaw,0 ;movement If KeyDown(17) vz=vz+0.04 ElseIf KeyDown(31) vz=vz-0.04 EndIf vz=vz*0.9 If KeyDown(30) vx=vx-0.04 ElseIf KeyDown(32) vx=vx+0.04 EndIf vx=vx*0.9 ;steps and floor collisions pick=LinePick (EntityX(player),EntityY(player),EntityZ(player),0,-playerheight,0) If pick PositionEntity player,EntityX(player),PickedY()+playerheight#,EntityZ(player) vy=0 EndIf vy=vy-.2 vy=vy*0.9 ;move player pivot MoveEntity player,vx,0,vz TranslateEntity player,0,vy,0 ;move camera + player meshes smoothly PositionEntity camera,EntityX(player),EntityY(camera),EntityZ(player) TranslateEntity camera,0,(EntityY(player)-(EntityY(camera)-cameraheight))*0.1,0 End Function Function NextChild(ent) If CountChildren(ent)>0 Return GetChild(ent,1) EndIf Local foundunused=False Local foundent = 0, parent,sibling While foundunused=False And ent<>0 parent = GetParent(ent) If parent<>0 If CountChildren(parent)>1 If GetChild(parent,CountChildren(parent))<>ent For siblingcnt = 1 To CountChildren(parent) sibling = GetChild(parent,siblingcnt) If sibling=ent foundunused = True foundent = GetChild(parent,siblingcnt+1) EndIf Next EndIf EndIf EndIf ent = parent Wend Return foundent End Function Fixed version up! the old version had bad code for setting up pickable geometry. This version solves the problem and adds a comment. I am also changing the original source to reflect this now... :)

Rob (Posted 2004) [#8]

Oh yeah - thanks to beaker for the nextchild function which makes looping through children very easy.

GR (Posted 2004) [#9]

Thanks VERY much! I really appreciate you taking the time to help me out. I really do. :) Cheers. Steve