3D Terrain

[james2464]

I've managed to figure out how to produce random terrain using a grid of triangles, and then assigning a slightly random z value to the points.   It's very primitive but could be useful to build on.   

But for now I'm stuck on how to detect or collide with this terrain.   It might be very complicated, or perhaps not.   Right now the spectator viewing is just like ghost mode, as in you can fly around and go through everything.   I'd like to make it so you can't pass through the textures at all.   Then if I can choose some textures as OK to pass throught (such as water surface) and others NOT OK to pass through, such as land, that would be ideal.   And later on, I'd like to be able to put a character on the surface and control it.    For now though, I'd like to understand how to detect these surfaces.    A square/rectangle room is not a problem, because you can just set limits on X,Y,Z movement.   Any flat surface is easy this way.   But the random terrain seems to need a different approach.

Code: (Select All)

'3d terrain on water - james2464 - Jan 2023
'Credit to 3D program and tutorial by MasterGy

Option _Explicit
Randomize Timer

Screen _NewImage(1000, 1000, 32)

Const pip180 = 3.141592 / 180

Dim Shared c(100) As Long
Dim scr, da, db, da2, dega, db2, degb, ss, ap, sqa
Dim sky_points, sky_image, actual_point, asq
Dim wx0, wy0, wz0, wx1, wy1, wz1, wx2, wy2, wz2, wx3, wy3, wz3, sx0, sy0, sx1, sy1, sx2, sy2, sx3, sy3
Dim mousex, mousey, mw, mouse_sens, vec_x, vec_y, vec_z, speed, moving
Dim sp3
Dim t, x, y, h, b, tz
Dim Shared trx(5000), try(5000), trz(5000) 'terrain points
Dim Shared fr1(5000), fr2(5000), fr3(5000), fr4(5000), fr5(5000), fr6(5000) 'terrain point groups  (hex)
Dim Shared maxterrain, maxp, shx, shy, shz

Cls


colour1

Dim Shared floor1, wall1, wall2, ground1, sky1, cbx(20)



wall1 = _NewImage(500, 100, 32): makewall
wall2 = _NewImage(500, 100, 32): makewall2
ground1 = _NewImage(500, 500, 32): makeground
'ground1 = _LoadImage("painting.jpg", 32)
sky1 = _NewImage(750, 750, 32): makesky

maketerrain

For t = 0 To 10: cbx(t) = _NewImage(400, 400, 32): Next t: makepallette

Dim Shared tximage(200)
For t = 0 To 10: tximage(t) = _CopyImage(cbx(t), 33): Next t

tximage(11) = _CopyImage(ground1, 33)
tximage(12) = _CopyImage(wall1, 33) 'office wall solid
tximage(13) = _CopyImage(wall2, 33) 'office wall with 3 windows


Type mapobject
    n As Integer 'object number
    x As Single 'x origin
    y As Single 'y origin
    z As Single 'z origin
    x1 As Single
    y1 As Single
    z1 As Single
    x2 As Single
    y2 As Single
    z2 As Single
    x3 As Single
    y3 As Single
    z3 As Single
    x4 As Single
    y4 As Single
    z4 As Single
    ix As Single 'image x
    iy As Single 'image y
    in As Integer 'image number - tximage()
End Type
Dim Shared raw(100) As mapobject, oo(900) As mapobject

'create texture point data array
Dim Shared tx(500, 19), txtot, rawtxtot

'objects and data points
Data 1,0,0,0,-1000,0,200,-1000,0,-200,1000,0,200,1000,0,-200,500,100,12: 'wall
Data 2,0,0,0,-4000,-4000,0,-4000,4000,0,4000,-4000,0,4000,4000,0,500,100,3: 'water

rawtxtot = 2: txtot = rawtxtot

'read data into array tx()
Dim t2
For t = 1 To txtot
    For t2 = 1 To 19
        Read tx(t, t2)
    Next t2
    'create 'raw' objects
    raw(t).n = tx(t, 1): raw(t).x = tx(t, 2): raw(t).y = tx(t, 3): raw(t).z = tx(t, 4)
    raw(t).x1 = tx(t, 5): raw(t).y1 = tx(t, 6): raw(t).z1 = tx(t, 7)
    raw(t).x2 = tx(t, 8): raw(t).y2 = tx(t, 9): raw(t).z2 = tx(t, 10)
    raw(t).x3 = tx(t, 11): raw(t).y3 = tx(t, 12): raw(t).z3 = tx(t, 13)
    raw(t).x4 = tx(t, 14): raw(t).y4 = tx(t, 15): raw(t).z4 = tx(t, 16)
    raw(t).ix = tx(t, 17): raw(t).iy = tx(t, 18): raw(t).in = tx(t, 19)
Next t


'object copies
Dim nn, nc, xc, yc, zc, ac
'nn = 1: nc = 1: xc = 0: yc = 0: zc = 400: ac = 0: objectcopy nn, nc, xc, yc, zc, ac 'wall
nn = 1: nc = 2: xc = 0: yc = 0: zc = 500: ac = 0: objectcopy nn, nc, xc, yc, zc, ac 'water


'create spectator
Dim Shared sp(6)
sp(0) = 0 'X position
sp(1) = 1500 'Y
sp(2) = 400 'Z
sp(3) = 0 'looking in the direction of the observer XZ
sp(4) = 0 'looking in the direction of the observer YZ
sp(5) = 1 'multiplier X-Y see
sp(6) = 1 'multiplier Z see

'create screen
scr = _NewImage(1000, 1000 / _DesktopWidth * _DesktopHeight, 32)
Screen scr
_MouseHide
_FullScreen
_Dest scr
_DisplayOrder _Hardware , _Software


'sky install
da = 11 'resolution sphere X
db = 7 'resolution sphere Y

sky_points = da * db
Dim sky_points(sky_points - 1, 9), sq(sky_points - 1, 7)
'sky_image = _LoadImage("sky.jpg", 33)
sky_image = _CopyImage(sky1, 33)

For da2 = 0 To da - 1
    dega = 360 / (da - 1) * da2 * pip180
    For db2 = 0 To db - 1
        degb = 180 / (db - 1) * db2 * pip180
        ss = 4000
        ap = da2 * db + db2
        sky_points(ap, 0) = Sin(degb) * Cos(dega) * ss
        sky_points(ap, 1) = Sin(degb) * Sin(dega) * ss
        sky_points(ap, 2) = Cos(degb) * ss
    Next db2
Next da2

For da2 = 0 To da - 2
    For db2 = 0 To db - 2
        sqa = da2 * db + db2
        sq(sqa, 0) = sqa
        sq(sqa, 1) = sq(sqa, 0) + 1
        sq(sqa, 2) = sq(sqa, 0) + db
        sq(sqa, 3) = sq(sqa, 2) + 1
        sq(sqa, 4) = _Width(sky_image) - (_Width(sky_image) / (da - 1) * da2) - 1
        sq(sqa, 5) = _Width(sky_image) - (_Width(sky_image) / (da - 1) * (da2 + 1)) - 1
        sq(sqa, 6) = Int(_Height(sky_image) / (db - 1) * db2)
        sq(sqa, 7) = Int(_Height(sky_image) / (db - 1) * (db2 + 1))
    Next db2
Next da2


'=============================================================================================================
'=============================================================================================================
'=============================================================================================================
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Do
    _Limit 40

    processterrain
    processtextures



    'draw sky    *********************************************************************************
    't = 1  'use for checkered sky

    'rotating
    For actual_point = 0 To sky_points - 1
        sky_points(actual_point, 4) = sky_points(actual_point, 0)
        sky_points(actual_point, 5) = sky_points(actual_point, 1)
        sky_points(actual_point, 6) = sky_points(actual_point, 2)
        r2m sky_points(actual_point, 4), sky_points(actual_point, 5), sky_points(actual_point, 6)
    Next actual_point

    For asq = 0 To sky_points - 1
        wx0 = sky_points(sq(asq, 0), 4) + 0: wy0 = sky_points(sq(asq, 0), 5) + 0: wz0 = sky_points(sq(asq, 0), 6)
        wx1 = sky_points(sq(asq, 1), 4) + 0: wy1 = sky_points(sq(asq, 1), 5) + 0: wz1 = sky_points(sq(asq, 1), 6)
        wx2 = sky_points(sq(asq, 2), 4) + 0: wy2 = sky_points(sq(asq, 2), 5) + 0: wz2 = sky_points(sq(asq, 2), 6)
        wx3 = sky_points(sq(asq, 3), 4) + 0: wy3 = sky_points(sq(asq, 3), 5) + 0: wz3 = sky_points(sq(asq, 3), 6)
        sy0 = sq(asq, 6): sx0 = sq(asq, 4): sy1 = sq(asq, 7): sx1 = sq(asq, 4): sy2 = sq(asq, 6): sx2 = sq(asq, 5): sy3 = sq(asq, 7): sx3 = sq(asq, 5)
        't = t * -1 'use for checkered sky
        'If t > 0 Then 'use for checkered sky
        _MapTriangle (sx0, sy0)-(sx1, sy1)-(sx2, sy2), sky_image To(wx0, wy0, wz0)-(wx1, wy1, wz1)-(wx2, wy2, wz2), , _Smooth
        _MapTriangle (sx3, sy3)-(sx1, sy1)-(sx2, sy2), sky_image To(wx3, wy3, wz3)-(wx1, wy1, wz1)-(wx2, wy2, wz2), , _Smooth
        'End If 'use for checkered sky
    Next asq
    ' ****************************************************************************************************

    _Display


    '-------------------------------------------------------------
    'mouse input axis movement and mousewheel
    '-------------------------------------------------------------
    mousex = mousex * .6
    mousey = mousey * .6
    mw = 0
    While _MouseInput: mousex = mousex + _MouseMovementX: mousey = mousey + _MouseMovementY: mw = mw + _MouseWheel: Wend 'movement data read

    'control spectator
    mouse_sens = .0007 'mouse rotating sensitive
    sp(3) = sp(3) - mousex * mouse_sens
    sp(4) = sp(4) + mousey * mouse_sens
    If Abs(sp(4)) > _Pi / 2 Then sp(4) = _Pi / 2 * Sgn(sp(4))
    sp3 = sp(3) + (_KeyDown(Asc("d")) - _KeyDown(Asc("a"))) * 90 * pip180
    vec_x = (Sin(sp3) * (Cos(sp(4) + _Pi)))
    vec_y = (Cos(sp3) * (Cos(sp(4) + _Pi)))
    vec_z = -Sin(sp(4) + _Pi)
    If _KeyDown(Asc("a")) Or _KeyDown(Asc("d")) Then vec_z = 0
    speed = 2.5 'moving speed
    moving = Abs(_MouseButton(1) Or _KeyDown(Asc("w")) Or _KeyDown(Asc("a")) Or _KeyDown(Asc("d"))) * speed - Abs(_MouseButton(2) Or _KeyDown(Asc("s"))) * speed
    sp(0) = sp(0) + vec_x * moving
    sp(1) = sp(1) + vec_y * moving
    sp(2) = sp(2) + vec_z * moving

    'If sp(0) > 465 Then sp(0) = 465
    'If sp(1) > 465 Then sp(1) = 465
    'If sp(0) < -465 Then sp(0) = -465
    'If sp(1) < -465 Then sp(1) = -465

Loop Until _KeyDown(27)



'=============================================================================================================
'=============================================================================================================
'=============================================================================================================
'=============================================================================================================



Sub r2m (x, y, z)
    Dim x2, y2, z2
    x2 = x - sp(0)
    y2 = y - sp(1)
    z2 = z - sp(2)
    rotate_2d x2, y2, sp(3)
    rotate_2d y2, z2, sp(4) + _Pi / 2
    x = x2 * sp(5)
    y = y2 * sp(5)
    z = z2 * sp(6)
End Sub

Sub rotate_2d (x, y, ang)
    Dim x1, y1
    x1 = x * Cos(ang) - y * Sin(ang)
    y1 = x * Sin(ang) + y * Cos(ang)
    x = x1: y = y1
End Sub



Sub processtextures
    Dim t, x, y, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4

    For t = 1 To txtot
        x1 = oo(t).x1: y1 = oo(t).y1: z1 = oo(t).z1
        x2 = oo(t).x2: y2 = oo(t).y2: z2 = oo(t).z2
        x3 = oo(t).x3: y3 = oo(t).y3: z3 = oo(t).z3
        x4 = oo(t).x4: y4 = oo(t).y4: z4 = oo(t).z4
        x = oo(t).ix: y = oo(t).iy
        r2m x1, y1, z1
        r2m x2, y2, z2
        r2m x3, y3, z3
        r2m x4, y4, z4
        _MapTriangle (0, 0)-(0, y)-(x, 0), tximage(oo(t).in) To(x1, y1, z1)-(x2, y2, z2)-(x3, y3, z3), , _Smooth
        _MapTriangle (x, y)-(0, y)-(x, 0), tximage(oo(t).in) To(x4, y4, z4)-(x2, y2, z2)-(x3, y3, z3), , _Smooth
    Next t

End Sub

Sub processterrain
    Dim t, t2, x, y, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4
    Dim xx1, yy1, zz1, xx2, yy2, zz2, xx3, yy3, zz3, xx4, yy4, zz4
    Dim flag, ct, scale1, txm
    flag = 0
    ct = 0
    scale1 = 2.
    shx = -500 'shift x position
    shy = -500 'shift y position
    shz = 502 'shift z position

    Do
        ct = ct + 1

        x1 = trx(fr1(ct)): y1 = try(fr1(ct)): z1 = trz(fr1(ct))
        x2 = trx(fr2(ct)): y2 = try(fr2(ct)): z2 = trz(fr2(ct))
        x3 = trx(fr3(ct)): y3 = try(fr3(ct)): z3 = trz(fr3(ct))

        xx1 = x1: yy1 = y1
        xx2 = x2: yy2 = y2
        xx3 = x3: yy3 = y3


        x1 = x1 * scale1: y1 = y1 * scale1: 'z1 = z1 * scale1
        x2 = x2 * scale1: y2 = y2 * scale1: 'z2 = z2 * scale1
        x3 = x3 * scale1: y3 = y3 * scale1: 'z3 = z3 * scale1


        x1 = x1 + shx: y1 = y1 + shy: z1 = z1 + shz
        x2 = x2 + shx: y2 = y2 + shy: z2 = z2 + shz
        x3 = x3 + shx: y3 = y3 + shy: z3 = z3 + shz


        r2m x1, y1, z1
        r2m x2, y2, z2
        r2m x3, y3, z3

        txm = 11
        _MapTriangle (xx1, yy1)-(xx2, yy2)-(xx3, yy3), tximage(txm) To(x1, y1, z1)-(x2, y2, z2)-(x3, y3, z3), , _Smooth

        If ct >= maxp Then flag = 1
    Loop Until flag = 1

End Sub


Sub objectcopy (nn, nc, xc, yc, zc, ac)
    Dim ct, t, t2, xt, yt
    ct = 0
    For t = 1 To rawtxtot
        If raw(t).n = nc Then
            ct = ct + 1
            t2 = txtot + ct
            oo(t2).n = nn: oo(t2).x = xc: oo(t2).y = yc: oo(t2).z = zc
            xt = raw(t).x1: yt = raw(t).y1: xyrotation xt, yt, ac: oo(t2).x1 = xt + xc: oo(t2).y1 = yt + yc: oo(t2).z1 = raw(t).z1 + zc
            xt = raw(t).x2: yt = raw(t).y2: xyrotation xt, yt, ac: oo(t2).x2 = xt + xc: oo(t2).y2 = yt + yc: oo(t2).z2 = raw(t).z2 + zc
            xt = raw(t).x3: yt = raw(t).y3: xyrotation xt, yt, ac: oo(t2).x3 = xt + xc: oo(t2).y3 = yt + yc: oo(t2).z3 = raw(t).z3 + zc
            xt = raw(t).x4: yt = raw(t).y4: xyrotation xt, yt, ac: oo(t2).x4 = xt + xc: oo(t2).y4 = yt + yc: oo(t2).z4 = raw(t).z4 + zc
            oo(t2).ix = raw(t).ix: oo(t2).iy = raw(t).iy: oo(t2).in = raw(t).in
        End If
    Next t
    txtot = txtot + ct
End Sub



Sub xyrotation (x, y, a)
    Dim xt, yt, h, h1, h2, xt2, yt2
    xt = x: yt = y
    h = _Hypot(yt, xt)
    h1 = _Atan2(xt, yt)
    h2 = h1 - a
    xt2 = Sin(h2) * h
    yt2 = Cos(h2) * h
    x = xt2
    y = yt2
End Sub



Sub makefloor
    Dim t, x1, y1
    Cls
    Line (0, 0)-(500, 500), c(18), BF 'floor background

    For t = 1 To 6000
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 500): PSet (x1, y1), c(0)
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 500): PSet (x1, y1), c(2)
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 500): PSet (x1, y1), c(3)
    Next t
    '_Display
    _PutImage (0, 0)-(500, 500), 0, floor1, (0, 0)-(500, 500)
    'Sleep
End Sub



Sub makewall
    Dim t, x1, y1
    Cls
    Line (0, 0)-(500, 100), c(7), BF 'wall background
    For t = 1 To 6000
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 100): PSet (x1, y1), c(8)
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 100): PSet (x1, y1), c(9)
    Next t
    '_Display
    _PutImage (0, 0)-(500, 100), 0, wall1, (0, 0)-(500, 100)
    _ClearColor c(0), wall1
    'Sleep
End Sub


Sub makewall2
    Dim t, x1, y1
    Cls
    Line (0, 0)-(500, 100), c(7), BF 'wall2 background
    For t = 1 To 6000
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 100): PSet (x1, y1), c(8)
        x1 = Int(Rnd * 500): y1 = Int(Rnd * 100): PSet (x1, y1), c(9)
    Next t
    Line (70, 25)-(150, 75), c(0), BF
    Line (210, 25)-(290, 75), c(0), BF
    Line (350, 25)-(430, 75), c(0), BF
    '_Display
    _PutImage (0, 0)-(500, 100), 0, wall2, (0, 0)-(500, 100)
    _ClearColor c(0), wall2
    'Sleep
End Sub




Sub makeground
    Dim t, x1, y1, s, s2
    s = 220
    s2 = (500 - s) / 2
    Cls
    Line (0, 0)-(500, 500), c(14), BF 'border/beach
    Line (0, 0)-(500, 500), c(40), BF 'ground background
    For t = 1 To 155
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        Line (x1 - 30, y1 - 30)-(x1 + 30, y1 + 30), c(41), BF
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        Line (x1 - 50, y1 - 50)-(x1 + 50, y1 + 50), c(42), BF
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        Line (x1 - 20, y1 - 20)-(x1 + 20, y1 + 20), c(43), BF
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        Line (x1 - 20, y1 - 20)-(x1 + 20, y1 + 20), c(44), BF
    Next t
    s = 790
    s2 = (500 - s) / 2

    For t = 1 To 7500
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(41)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(42)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(43)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(44)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(41)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(42)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(43)
        x1 = Int(Rnd * s) + s2: y1 = Int(Rnd * s) + s2
        PSet (x1, y1), c(44)

    Next t
    'Line (5, 5)-(495, 10), c(31), BF
    'Line (5, 495)-(495, 490), c(32), BF
    'Line (490, 5)-(495, 495), c(33), BF
    'Line (5, 5)-(10, 495), c(34), BF
    '_Display
    _PutImage (0, 0)-(500, 500), 0, ground1, (0, 0)-(500, 500)
    'Sleep
End Sub







Sub maketerrain
    Dim t, s, x, y, x1, y1, p, q, p2, ct, ct2, flag
    Dim xt, yt, xh, yh, vc, fx, fx1, fx2, mx, oldct
    Cls
    Line (0, 0)-(500, 500), c(1), B
    t = 0
    x1 = 500: y1 = 500
    s = 25
    fx = 1
    maxterrain = 0
    'create points  (trx,try,trz)
    For y = 0 To y1 Step s

        fx = Int(fx * -1)
        If fx > 0 Then
            fx1 = 0
        Else fx1 = s / 2
        End If

        For x = fx1 To x1 Step s
            t = t + 1
            trx(t) = x: try(t) = y
            Circle (x, y), 3, c(1)
            If x > s And x < x1 - s Then
                If y > s And y < y1 - s Then
                    'trz(t) = 0
                    trz(t) = 0 - Int(Rnd * 17) - 5
                    xh = Abs(trx(t) - x1 / 2)
                    yh = Abs(try(t) - y1 / 2)
                    vc = _Hypot(xh, yh)
                    vc = 170 - vc
                    trz(t) = trz(t) - vc / 4
                    'trz(t) = trz(t) - (Int(Rnd * vc))
                End If
            End If
        Next x
    Next y
    '_Display
    'Sleep
    maxterrain = t


    'display points
    p = Int(x1 / s) + 1
    q = Int(y1 / s) - 1
    fx = 1
    t = 0
    oldct = 0

    For y = 0 To y1 Step s
        fx = Int(fx * -1)
        If fx > 0 Then
            fx1 = 0
        Else fx1 = s / 2
        End If
        For x = fx1 To x1 Step s
            t = t + 1
            If y > s Then
                If x > s Then
                    If x < x1 - s Then
                        If y < y1 - s Then
                            Circle (trx(t), try(t)), 2, c(1)
                            Circle (trx(t), try(t)), 1, c(1)
                            Circle (trx(oldct), try(oldct)), 2, c(0)
                            Circle (trx(oldct), try(oldct)), 1, c(0)
                            'Line (trx(t), try(t))-(trx(t - p), try(t - p)), c(1)
                            'Line (trx(t), try(t))-(trx(t - p + 1), try(t - p + 1)), c(1)
                            'Line (trx(t), try(t))-(trx(t + p - 1), try(t + p - 1)), c(1)
                            'Line (trx(t), try(t))-(trx(t + p), try(t + p)), c(1)
                            'Line (trx(t), try(t))-(trx(t - 1), try(t - 1)), c(1)
                            'Line (trx(t), try(t))-(trx(t + 1), try(t + 1)), c(1)
                            oldct = t
                            '_Display
                            'Sleep
                            'Line (trx(t), try(t))-(trx(t - p), try(t - p)), c(0)
                            'Line (trx(t), try(t))-(trx(t - p + 1), try(t - p + 1)), c(0)
                            'Line (trx(t), try(t))-(trx(t + p - 1), try(t + p - 1)), c(0)
                            'Line (trx(t), try(t))-(trx(t + p), try(t + p)), c(0)
                            'Line (trx(t), try(t))-(trx(t - 1), try(t - 1)), c(0)
                            'Line (trx(t), try(t))-(trx(t + 1), try(t + 1)), c(0)

                        End If
                    End If
                End If
            End If
        Next x
    Next y

    '_Display
    'Sleep


    'create point groups (fr1,fr2,fr3)
    p = Int(x1 / s) + 1
    q = Int(y1 / s) - 1
    fx = 1
    t = 0
    ct = 0
    oldct = 0

    For y = 0 To y1 - 1 Step s
        fx = Int(fx * -1)
        If fx > 0 Then
            fx1 = 0
        Else fx1 = s / 2
        End If
        For x = fx1 To x1 Step s
            t = t + 1
            If fx > 0 Then

                ct = ct + 1
                fr1(ct) = t
                fr2(ct) = t - p
                fr3(ct) = t - p + 1
                Line (trx(t), try(t))-(trx(t - p), try(t - p)), c(32)
                Line (trx(t), try(t))-(trx(t - p + 1), try(t - p + 1)), c(32)
                Line (trx(t - p), try(t - p))-(trx(t - p + 1), try(t - p + 1)), c(32)
                '_Display
                'Sleep

                ct = ct + 1
                fr1(ct) = t
                fr2(ct) = t + p
                fr3(ct) = t + p - 1
                Line (trx(t), try(t))-(trx(t + p), try(t + p)), c(1)
                Line (trx(t), try(t))-(trx(t + p - 1), try(t + p - 1)), c(1)
                Line (trx(t + p), try(t + p))-(trx(t + p - 1), try(t + p - 1)), c(1)
                '_Display
                'Sleep

            Else

                ct = ct + 1
                fr1(ct) = t
                fr2(ct) = t + p
                fr3(ct) = t + p - 1
                Line (trx(t), try(t))-(trx(t + p), try(t + p)), c(33)
                Line (trx(t), try(t))-(trx(t + p - 1), try(t + p - 1)), c(33)
                Line (trx(t + p), try(t + p))-(trx(t + p - 1), try(t + p - 1)), c(33)
                '_Display
                'Sleep

                ct = ct + 1
                fr1(ct) = t + p + p - 1
                fr2(ct) = t + p
                fr3(ct) = t + p - 1
                Line (trx(t + p + p - 1), try(t + p + p - 1))-(trx(t + p), try(t + p)), c(34)
                Line (trx(t + p + p - 1), try(t + p + p - 1))-(trx(t + p - 1), try(t + p - 1)), c(34)
                Line (trx(t + p), try(t + p))-(trx(t + p - 1), try(t + p - 1)), c(34)
                '_Display
                'Sleep
            End If


            oldct = t
            Locate 35, 1
            Print t, ct
            '_Display
            'Sleep
        Next x
    Next y
    maxp = ct


    'fr1(t) = t - p
    'fr2(t) = t - p + 1
    'fr3(t) = t + p - 1




    'Cls
    't = t + 1
    'For ct = 1 To t
    'Print fr1(ct), fr2(ct), fr3(ct)
    'Next ct



    '_Display
    'Sleep

End Sub





Sub makesky
    Dim t, y, m
    Cls
    y = 750
    For t = 1 To y
        m = 255 * ((750 - t * .65) / 750)
        c(99) = _RGBA(200, 200, 255, m)
        Line (0, t)-(750, t), c(99)
    Next t
    'For t = 0 To 750 Step 25 'longituge lines
    'Line (t, 0)-(t, 750), c(1)
    'Next t
    'For t = 0 To 750 Step 25 'latitude lines
    'Line (0, t)-(750, t), c(1)
    'Next t
    '_Display
    _PutImage (0, 0)-(750, 750), 0, sky1, (0, 0)-(750, 750)
    'Sleep
End Sub




Sub makepallette
    Dim t
    For t = 0 To 10
        Cls
        Line (0, 0)-(400, 400), c(t), BF
        _PutImage (0, 0)-(400, 400), 0, cbx(t), (0, 0)-(400, 400)
        '_Display
        'Sleep
    Next t
End Sub



Sub colour1
    c(0) = _RGB(0, 0, 0)
    c(1) = _RGB(255, 255, 255)
    c(2) = _RGB(35, 25, 10)
    c(3) = _RGB(10, 45, 65)
    c(4) = _RGB(40, 50, 10)
    c(5) = _RGB(0, 25, 75)
    c(6) = _RGB(45, 35, 20)
    c(7) = _RGB(150, 150, 150)
    c(8) = _RGB(125, 125, 125)
    c(9) = _RGB(100, 100, 100)
    c(10) = _RGBA(75, 75, 75, 151)
    c(11) = _RGB(0, 0, 0)
    c(12) = _RGB(35, 25, 10)
    c(13) = _RGB(0, 45, 85)
    c(14) = _RGB(160, 150, 100)
    c(15) = _RGB(0, 25, 75)
    c(16) = _RGB(55, 25, 30)
    c(17) = _RGB(175, 175, 175)
    c(18) = _RGB(100, 100, 100)
    c(20) = _RGB(20, 30, 15)
    c(31) = _RGB(255, 255, 255)
    c(32) = _RGB(255, 0, 0)
    c(33) = _RGB(0, 55, 255)
    c(34) = _RGB(255, 255, 0)
    c(40) = _RGBA(45, 20, 25, 125)
    c(41) = _RGBA(50, 50, 30, 40)
    c(42) = _RGBA(20, 30, 15, 40)
    c(43) = _RGBA(75, 45, 15, 40)
    c(44) = _RGBA(40, 60, 30, 40)
    c(45) = _RGB(50, 50, 30)
    c(46) = _RGB(20, 30, 15)
    c(47) = _RGB(55, 45, 15)
    c(48) = _RGB(40, 50, 10)

End Sub

[mnrvovrfc]

I wanted to be on that lonely island. Nice job!

[OldMoses]

A couple of thoughts:

If there's a simple solution, I don't know it.

I think it would probably involve some sort of parametric algorithm after determining which triangle grid element was being approached. I've not done anything like that myself, having mostly worked with line/sphere intersections. Most line/plane intersection stuff I've looked at presumes an infinite plane, so you would need to narrow your inputs to the correct grid element with some Pythagorean checking.

https://courseware.cemc.uwaterloo.ca/web...APlane.pdf
There's lots of other stuff on parametric equations available.

The other possibility, is that you can take the plane 'normal' {i.e. perpendicular} of a target terrain grid element, and dot it with the position vector relative to that normal, updating it as you go along the path (easier to do than to describe). When the sign of the dot product result changes, you've intersected the plane, and likely gone through it. If the dot product result went to zero and stayed there, you would be moving along the plane. It would be a 3D version of what we were discussing at https://qb64phoenix.com/forum/showthread.php?tid=972  Generally, the same concepts apply for 3D as for 2D

The former would have the advantage of being able to calculate exact points of intersection, the later would be computationally simpler for a crash scenario.

[MasterGy]

I rewrote it to universal. in this example, the DEEP array records the height values. The height value can be easily read.

1 square grid = 2 triangles. He counts with the one that falls into a triangle.

Code: (Select All)

Function exact_deep (x, y)
    x1 = Int(x): x2 = x1 + 1: aposx = (x - x1)
    y1 = Int(y): y2 = y1 + 1: aposy = (y - y1)
    p1 = deep(x2, y1)
    p2 = deep(x1, y2)
    If aposx * aposx + aposy * aposy < (1 - aposx) * (1 - aposx) + (1 - aposy) * (1 - aposy) Then
        p0 = deep(x1, y1)
        q = p0 + aposx * (p1 - p0) + aposy * (p2 - p0)
    Else
        p3 = deep(x2, y2)
        q = p3 + (1 - aposy) * (p1 - p3) + (1 - aposx) * (p2 - p3)
    End If
    exact_deep = q
End Function

[james2464]

I wanted to be on that lonely island. Nice job!

Thanks!  Just need a house on there, and maybe a boat too. 

[james2464]

A couple of thoughts:

If there's a simple solution, I don't know it.

I think it would probably involve some sort of parametric algorithm after determining which triangle grid element was being approached. I've not done anything like that myself, having mostly worked with line/sphere intersections. Most line/plane intersection stuff I've looked at presumes an infinite plane, so you would need to narrow your inputs to the correct grid element with some Pythagorean checking.

https://courseware.cemc.uwaterloo.ca/web...APlane.pdf
There's lots of other stuff on parametric equations available.

The other possibility, is that you can take the plane 'normal' {i.e. perpendicular} of a target terrain grid element, and dot it with the position vector relative to that normal, updating it as you go along the path (easier to do than to describe). When the sign of the dot product result changes, you've intersected the plane, and likely gone through it. If the dot product result went to zero and stayed there, you would be moving along the plane. It would be a 3D version of what we were discussing at https://qb64phoenix.com/forum/showthread.php?tid=972  Generally, the same concepts apply for 3D as for 2D

The former would have the advantage of being able to calculate exact points of intersection, the later would be computationally simpler for a crash scenario.

Thanks for the PDF...that should help make sense of this.   Some interesting math there too...quadradic equations?  Been a long time since I've done that.

Using vector math would really open up some possibilities.   Definitely over my head but this seems like the way to go for a good 3d physics engine.

[james2464]

I rewrote it to universal. in this example, the DEEP array records the height values. The height value can be easily read.

1 square grid = 2 triangles. He counts with the one that falls into a triangle.

Code: (Select All)

Function exact_deep (x, y)
    x1 = Int(x): x2 = x1 + 1: aposx = (x - x1)
    y1 = Int(y): y2 = y1 + 1: aposy = (y - y1)
    p1 = deep(x2, y1)
    p2 = deep(x1, y2)
    If aposx * aposx + aposy * aposy < (1 - aposx) * (1 - aposx) + (1 - aposy) * (1 - aposy) Then
        p0 = deep(x1, y1)
        q = p0 + aposx * (p1 - p0) + aposy * (p2 - p0)
    Else
        p3 = deep(x2, y2)
        q = p3 + (1 - aposy) * (p1 - p3) + (1 - aposx) * (p2 - p3)
    End If
    exact_deep = q
End Function

Thank you!   I'll try to make this work.   Cheers!

[MasterGy]

I checked. it will work. You should record the depth data in the following way and it will be compatible with this.

I hope everything is understandable in the example! good luck !

Code: (Select All)

Dim Shared deep(4, 4)


deep(0, 0) = 10
deep(1, 0) = 20
deep(0, 1) = 30
deep(1, 1) = 40


'deep-array now
' 10 20 0 0 0
' 30 40 0 0 0
'  0  0 0 0 0
'  0  0 0 0 0
'  0  0 0 0 0


Print exact_deep(0, 0) '10
Print exact_deep(0.5, 0) 'between 10 and 20
Print exact_deep(.5, .5) 'between central 10,20,30,40 (central 25)




Function exact_deep (x, y)
    x1 = Int(x): x2 = x1 + 1: aposx = x - x1
    y1 = Int(y): y2 = y1 + 1: aposy = y - y1

    p1 = deep(x2, y1)
    p2 = deep(x1, y2)

    If aposx * aposx + aposy * aposy < (1 - aposx) * (1 - aposx) + (1 - aposy) * (1 - aposy) Then
        p0 = deep(x1, y1)
        q = p0 + aposx * (p1 - p0) + aposy * (p2 - p0)
    Else
        p3 = deep(x2, y2)
        q = p3 + (1 - aposy) * (p1 - p3) + (1 - aposx) * (p2 - p3)
    End If

    exact_deep = q

End Function

[james2464]

Perfect.  I was working on creating the DEEP array (incorrectly) but now with this information I can set it up properly.   

Thank you!

[OldMoses]

Using vector math would really open up some possibilities.   Definitely over my head but this seems like the way to go for a good 3d physics engine.

You already are, truth be told. The only difference is your code handles the vectors as individual x/y/z components.

The main possibility is less overall typing and more succinct code. It's just a matter of thinking of those individual components as whole objects and writing some subroutines to handle the individual components of those objects.

I notice your SUB processterrain is doing just that. In the DO...LOOP, it's mostly scalar multiplications of, and additions to vectors, which could be SUB'ed out to something that would handle the grunt work. All that would be needed is a vector TYPE, say...

TYPE Vector
    x AS SINGLE
    y AS SINGLE
    z AS SINGLE
END TYPE

A subroutine to do the multiplications
SUB MultVec (v as Vector, m AS SINGLE)
    v.x = v.x * m
    v.y = v.y * m
    v.z = v.z * m
END SUB

Then just DIM AS Vector vec1, vec2, vec3 '  in the SUB

Suddenly:
 x1 = x1 * scale1: y1 = y1 * scale1: 'z1 = z1 * scale1
 x2 = x2 * scale1: y2 = y2 * scale1: 'z2 = z2 * scale1
 x3 = x3 * scale1: y3 = y3 * scale1: 'z3 = z3 * scale1

becomes:
MultiVec vec1, scale1
MultiVec vec2, scale1
MultiVec vec3, scale1

Then you can do the same to the vector additions. Change shx, shy & shz to a single vector type: sh.x, sh.y & sh.z. Write a sub to add two vectors together:

SUB AddVec (v1 as Vector, v2 AS Vector)
    v1.x = v1.x + v2.x
    v1.y = v1.y + v2.y
    v1.z = v1.z + v2.z
END SUB

Now:
x1 = x1 + shx: y1 = y1 + shy: z1 = z1 + shz
x2 = x2 + shx: y2 = y2 + shy: z2 = z2 + shz
x3 = x3 + shx: y3 = y3 + shy: z3 = z3 + shz

becomes:
AddVec vec1, sh
AddVec vec2, sh
AddVec vec3, sh

A little more upfront work for a big payoff in short code, more descriptive variable naming, etc.