Fake Lighting Techniques For Blitz3d

I use to work with this to solve exactly problem you mention about...you can add also nice sprites over light surface and make them changing transparency according to angle against camera..anyway, this will light your geometry, and change intensity of light applied on to level geometry according to distance from light source..

Graphics3D 1280,1024,32,1
SetBuffer BackBuffer()

HidePointer
AmbientLight 12,24,50
SeedRnd MilliSecs()

light = CreateLight()
RotateEntity light,70,40,0
LightColor light,50,50,50


camera = CreateCamera()
scene = CreateMesh()

For i = 0 To 100

cube = CreateCube()
ScaleMesh cube,Rnd(1,10),Rnd(1,10),Rnd(1,10)
RotateMesh cube,Rnd(-90,90),Rnd(-180,180),Rnd(-180,180)
PositionMesh cube,Rnd(-100,100),Rnd(-100,100),Rnd(-100,100)

AddMesh cube,scene

FreeEntity cube

Next

cube = CreateCube()
ScaleMesh cube,150,150,150
FlipMesh cube
AddMesh cube,scene
FreeEntity cube

DL_Init()
DL_SetReceiver(scene)

DL_SetLight(camera)

spd# = 2.0

Repeat

MoveEntity camera,(KeyDown(205)-KeyDown(203))*spd,0,(KeyDown(200)-KeyDown(208))*spd
TurnEntity camera,MouseYSpeed()*0.25,-MouseXSpeed()*0.25,0
RotateEntity camera,EntityPitch(camera,True),EntityYaw(camera,True),0

MoveMouse 320,240

DL_Update()

RenderWorld
Flip

Until KeyHit(1)

DL_Free()









Type dl_receiver
Field mesh
End Type

Type dl_light
Field entity
Field range#
Field scale#
Field intensity#
Field flicker#
Field flickerrange#
Field r#,g#,b#
End Type

Global dl_brush
Global dl_tex

Function DL_Init()

ClearTextureFilters
dl_tex = LoadTexture("your_light_source_texture.png",1+16+32)

dl_brush = CreateBrush()
BrushBlend dl_brush,3
BrushFX dl_brush,1+2
BrushTexture dl_brush,dl_tex

End Function

Function DL_Free()

For dlr.dl_receiver = Each dl_receiver
FreeEntity dlr\mesh
Delete dlr
Next

For dll.dl_light = Each dl_light
Delete dll
Next

If dl_tex Then FreeTexture dl_tex
If dl_brush Then FreeBrush dl_brush

dl_tex = 0
dl_brush = 0

End Function

Function DL_SetReceiver(mesh)

dlr.dl_receiver = New dl_receiver
dlr\mesh = CopyMesh(mesh)
PaintMesh dlr\mesh,dl_brush

End Function

Function DL_SetLight(entity,range#=500.0,scale#=0.75,intensity#=2.0,flicker#=0.05,flickerrange#=0.5,r#=200,g#=220,b#=255)

dll.dl_light = First dl_light

If dll = Null
dll.dl_light = New dl_light
End If

dll\entity = entity
dll\range = range
dll\scale = scale
dll\intensity = intensity
dll\flicker = flicker
dll\flickerrange = flickerrange

dll\r = r
dll\g = g
dll\b = b

End Function

Function DL_Update()

dll.dl_light = First dl_light
If dll = Null Then Return

If Rnd(0.0,9.0)<dll\flicker
intensity# = dll\intensity*Rnd(dll\flickerrange,1.0)
Else
intensity# = dll\intensity
End If

For dlr.dl_receiver = Each dl_receiver
mesh = dlr\mesh
n_surfs = CountSurfaces(mesh)
For s = 1 To n_surfs
surf = GetSurface(mesh,s)
n_verts = CountVertices(surf)-1
For v = 0 To n_verts
TFormPoint VertexX(surf,v),VertexY(surf,v),VertexZ(surf,v),mesh,dll\entity
x# = TFormedX()
y# = TFormedY()
z# = TFormedZ()

dist# = Sqr(x*x + y*y + z*z)*dll\scale
tu# = (x/dist)+0.5
tv# = 1.0-((y/dist)+0.5)

VertexTexCoords surf,v,tu,tv

If z>dll\range Then z = dll\range
falloff# = 1.0-(z/dll\range)
If falloff<0.0 Then falloff = 0.0
If falloff>1.0 Then falloff = 1.0

TFormNormal VertexNX(surf,v),VertexNY(surf,v),VertexNZ(surf,v),mesh,dll\entity
dot# = -TFormedZ()*falloff*intensity
If dot>0.0
VertexColor surf,v,dot*dll\r,dot*dll\g,dot*dll\b
Else
VertexColor surf,v,0,0,0
End If
Next
Next
Next

End Function