but i have added multi lights succesfully now:
Open in online IDEGraphics 640, 480, 32, 2 SetBuffer BackBuffer() SeedRnd MilliSecs() ;Raytracer InitRaytracer() CreateScene() ;Loadscreen SetFont LoadFont("Arial", GraphicsHeight() / 5, True, False, False) Text GraphicsWidth() / 2, GraphicsHeight() / 2, "Please wait...", True, True Flip ;Render Raytrace() Flip WaitKey() End Function CreateScene() AddEntity("Light", 50, 1000, 800) ;Light1 AddEntity("Light", -200, 200, 400) ;Light2 AddEntity("Plane", 1, 100, $857830) ;Floor AddEntity("Sphere", 100, 10, 200, 100, $FF0000) ;Red ball AddEntity("Sphere", -100, -80, 385, 100, $00FF00) ;Green ball AddEntity("Sphere", 0, -50, 510, 100, $0000FF) ;Blue ball SetCameraPosition(0, -25, -130) SetAmbientLight(255) End Function Type Light Field x#, y#, z# End Type Type Plane Field nx#, ny#, nz# Field dis# Field argb End Type Type Sphere Field x#, y#, z# Field rad# Field argb End Type Dim normalx#(-1, -1) Dim normaly#(-1, -1) Dim normalz#(-1, -1) Global camerax#, cameray#, cameraz# Global ambientcol Function InitRaytracer() w = GraphicsWidth() h = GraphicsHeight() Dim normalx#(w, h) Dim normaly#(w, h) Dim normalz#(w, h) SetupNormals() End Function Function Raytrace() Cls LockBuffer() width = GraphicsWidth() height = GraphicsHeight() For y = 0 To height - 1 For x = 0 To width - 1 rgb = SendRay(camerax#, cameray#, cameraz#, normalx#(x, y), normaly#(x, y), normalz#(x, y), ambientcol) If rgb <> $000000 Then WritePixelFast x, y, rgb, BackBuffer() Next Next UnlockBuffer() End Function Function SendRay(ex#, ey#, ez#, evx#, evy#, evz#, c = 255, recursive_times = 4) If recursive_times < 0 Then Return Local z# = 10000 l.Light = First Light For p.Plane = Each Plane nx# = p\nx# ny# = p\ny# nz# = p\nz# dis# = nx# * evx# + ny# * evy# + nz# * evz# If dis# < 0 Then dis2# = -(p\dis# + nx# * ex# + ny# * ey# + nz# * ez#) / dis# ix# = ex# + evx# * dis2# iy# = ey# + evy# * dis2# iz# = ez# + evz# * dis2# lvx# = l\x# - ix# lvy# = l\y# - iy# lvz# = l\z# - iz# dis# = Sqr(lvx# * lvx# + lvy# * lvy# + lvz# * lvz#) lvx# = lvx# / dis# lvy# = lvy# / dis# lvz# = lvz# / dis# dis# = (nx# * evx# + ny# * evy# + nz# * evz#) * 2 rnx# = evx# - nx# * dis# rny# = evy# - ny# * dis# rnz# = evz# - nz# * dis# c1 = (nx# * lvx# + ny# * lvy# + nz# * lvz#) * 256 argb = p\argb z# = dis2# EndIf Next c2 = 0 For s.Sphere = Each Sphere svx# = s\x# - ex# svy# = s\y# - ey# svz# = s\z# - ez# dis2# = svx# * evx# + svy# * evy# + svz# * evz# dis# = svx# * svx# + svy# * svy# + svz# * svz# - dis2# * dis2# If dis# <= s\rad# * s\rad# Then dis2# = dis2# - Sqr(s\rad# * s\rad# - dis#) If dis2# > 0 And dis2# < z# Then ix# = ex# + evx# * dis2# iy# = ey# + evy# * dis2# iz# = ez# + evz# * dis2# nx# = Float(ix# - s\x#) / s\rad# ny# = Float(iy# - s\y#) / s\rad# nz# = Float(iz# - s\z#) / s\rad# For l.Light = Each Light lvx# = l\x# - ix# lvy# = l\y# - iy# lvz# = l\z# - iz# dis# = Sqr(lvx# * lvx# + lvy# * lvy# + lvz# * lvz#) lvx# = lvx# / dis# lvy# = lvy# / dis# lvz# = lvz# / dis# dis# = (nx# * evx# + ny# * evy# + nz# * evz#) * 2 rnx# = evx# - nx# * dis# rny# = evy# - ny# * dis# rnz# = evz# - nz# * dis# c2 = c2 + (rnx# * lvx# + rny# * lvy# + rnz# * lvz#) ^ 10 * 256 Next c1 = (nx# * lvx# + ny# * lvy# + nz# * lvz#) * 256 argb = s\argb z# = dis2# EndIf EndIf Next sh = Shadowed(ix#, iy#, iz#) If c2 < 50 Then c2 = 50 If sh < 255 Then c1 = sh c2 = 0 Else c2 = c2 * 2 If c1 < 30 Then c1 = 30 If c2 < 0 Then c2 = 0 EndIf c3 = c1 * c Shr 8 r = (argb And $FF0000) * c3 Shr 8 + c2 Shl 16 g = (argb And $00FF00) * c3 Shr 8 + c2 Shl 8 b = (argb And $0000FF) * c3 Shr 8 + c2 If argb <> $000000 Then argb = SendRay(ix#, iy#, iz#, rnx#, rny#, rnz#, c - 32, recursive_times - 1) r = r + (argb And $FF0000) / 8 g = g + (argb And $00FF00) / 8 b = b + (argb And $0000FF) / 8 If r > $FF0000 Then r = $FF0000 Else r = r And $FF0000 If g > $00FF00 Then g = $00FF00 Else g = g And $00FF00 If b > $0000FF Then b = $0000FF Else b = b And $0000FF Return r Or g Or b End Function Function Shadowed(x#, y#, z#) col = 255 For l.Light = Each Light evx# = l\x# - x# evy# = l\y# - y# evz# = l\z# - z# dis# = Sqr(evx# * evx# + evy# * evy# + evz# * evz#) evx# = evx# / dis# evy# = evy# / dis# evz# = evz# / dis# ar = False For s.Sphere = Each Sphere svx# = s\x# - x# svy# = s\y# - y# svz# = s\z# - z# dis2# = svx# * evx# + svy# * evy# + svz# * evz# dis# = svx# * svx# + svy# * svy# + svz# * svz# - dis2# * dis2# If dis2# > 0 And dis# < s\rad# * s\rad# And ar = False Then col = col / 2 ar = True EndIf Next Next Return col End Function Function SetCameraPosition(x#, y#, z#) camerax# = x# cameray# = y# cameraz# = z# End Function Function SetAmbientLight(col) ambientcol = col End Function Function AddEntity(typ$, p1$ = "", p2$ = "", p3$ = "", p4$ = "", p5$ = "") Select Lower(typ$) Case "sphere" s.Sphere = New Sphere s\x# = p1$ s\y# = p2$ s\z# = p3$ s\rad# = p4$ s\argb = p5$ Case "plane" p.Plane = New Plane p\ny# = p1$ p\dis# = p2$ p\argb = p3$ Case "light" l.Light = New Light l\x# = p1$ l\y# = p2$ l\z# = p3$ Default RuntimeError "Entity type not found." End Select End Function Function SetupNormals() width = GraphicsWidth() height = GraphicsHeight() nz# = 200 For y = 0 To height - 1 ny# = Float(height Shr 1 - y) * 240.0 / Float(width) For x = 0 To width - 1 nx# = Float(width Shr 1 - x) * 240.0 / Float(width) dis# = Sqr(nx# * nx# + ny# * ny# + nz# * nz#) normalx#(x, y) = -nx# / dis# normaly#(x, y) = ny# / dis# normalz#(x, y) = nz# / dis# Next Next End Function