Hey.
I've been working on a 3d engine concept to see if the trig functions would work to give me a 3D simulation. It seems to work fine until you look up and down with the arrow keys. For some reason the horizon seems to bend and get all distorted.
If you look side to side it all seems OK.
Here is the concept...
Imagine you are standing in an array of glass blocks 14 x 14 x 14 and the corner of each block is a dot.
Here is the code...
; PROJECT : 3DMathCalcs
; AUTHOR : Kman
; CREATED : 4/3/2007
; EDITED : 4/4/2007
; ---------------------------------------------------------------------
;3D Math Calcs
;Input Variables
HBearing=0
VBearing=0
lz=0
px=3
py=2
pz=6
fv#=90
;Math Calcs
Do
a$=Inkey$()
Cls 0
For lz=-60 To 60 Step 10
For ly=-60 To 60 Step 10
For lx=-60 To 60 Step 10
dx=lx-px
dy=ly-py
dz=lz-pz
pd#=Sqrt(dx^2+dy^2)
pdz#=Sqrt(dz^2+pd#^2)
Pang#=HBearing-ASin(dx/pd#)
Zang#=VBearing-ASin(dz/pdz#)
vx#=Sin(Pang#)*pd#
vy#=Cos(Pang#)*pd#
vz#=Sin(Zang#)*pdz#
;Print pdz#
;Print "Vx="+Str$(vx#)
;Print "Vy="+Str$(vy#)
;Print "Vz="+Str$(vz#)
Ppu#=GetScreenWidth()/((Sin(fv#/2)*vy#)*2)
Sx=(GetScreenWidth()/2)-Ppu#*vx#
If Pang#>=90 And Pang#<=270
Sy=(GetScreenHeight()/2)-PPu#*vz#
Else
Sy=(GetScreenHeight()/2)+PPu#*vz#
EndIf
If sx>0 And sx<800 And Sy>0 And Sy<600
DotC Sx,Sy,RGB(255,255, 0)
EndIf
;Print vz#
;Print "Sx="+Str$(Sx)
;Print "Sy="+Str$(Sy)
Next lx
Next ly
Next lz
If RightKey()=True
Hbearing=Hbearing+5:If Hbearing>359 Then Hbearing=0
EndIf
If LeftKey()=True
HBearing=Hbearing-5:If Hbearing<0 Then Hbearing=359
EndIf
If UpKey()=True
Dec Vbearing:If Vbearing<-45 Then Vbearing=-45
EndIf
If DownKey()=True
Inc VBearing:If Vbearing>45 Then Vbearing=45
EndIf
If a$="8"
px=px+Sin(HBearing)
py=py+Cos(Hbearing)
EndIf
If DownKey()=True
Inc VBearing:If Vbearing>45 Then Vbearing=45
EndIf
SetCursor 0,0
Print Hbearing
Print VBearing
Print Sy
Sync
Loop
WaitKey
I think it has something to do with the conversion of virtual co-ordinates to screen co-ordinates
Any ideas
just to clarify-
HBearing is angle looking across
VBearing is looking up and down
Px,y,z is your position
fv# is your field of vision is degrees
