Creating a 3D Grid

Edit: I made the way the dots are displayed a lot better by adding functions and found out that I needed to do

For pos# = 0 To GridSize*(GridSpace^-1)
instead of
For pos# = 0 To GridSize

to show more dots when the GridSpace goes below 1

Global GridTexture
Global GridSize#=16
Global GridSpace#=2

InitGraphics(800,600,"GIA Map Editor")
GridTexture = CreateGridTexture(2+4)

Global DefaultLight = CreateLight()

Global cube[1]

cube[0] = CreateCube()
	EntityTexture cube[0],GridTexture

cube[1] = CreateCube()
	EntityTexture cube[1],GridTexture
	ScaleEntity cube[1],.25,.25,.25
	PositionEntity cube[1],3,0,0,1

Global Camera = CreateCamera()
	PositionEntity Camera,0,GridSize*.5,-GridSize*1.5
	CameraClsColor Camera,100,100,100
	CameraRange Camera,.01,1000
	RotateEntity Camera,20,0,0

Global Multiplier#=.5
Global TempPoints%

While Not KeyDown(1)
	
	If KeyHit(20) GridSize = GridSize + Multiplier
	If KeyHit(34) GridSize = GridSize - Multiplier
	
	If KeyHit(21) GridSpace = GridSpace + Multiplier
	If KeyHit(35) GridSpace = GridSpace - Multiplier
	
	If GridSize < Multiplier Then GridSize = Multiplier
	If GridSpace < Multiplier Then GridSpace = Multiplier
	
	If KeyDown(31) TranslateEntity Camera,0,0,-.25
	If KeyDown(17) TranslateEntity Camera,0,0,.25
	If KeyDown(32) TranslateEntity Camera,.25,0,0
	If KeyDown(30) TranslateEntity Camera,-.25,0,0
	If KeyDown(18) TranslateEntity Camera,0,.25,0
	If KeyDown(16) TranslateEntity Camera,0,-.25,0
	
	If KeyDown(200) TurnEntity Camera,-4,0,0
	If KeyDown(208) TurnEntity Camera,4,0,0
	
	TempPitch# = EntityPitch(Camera)
	RotateEntity Camera,TempPitch,0,0
	
	DrawWorld()
	
	TempPoints = 0
	
	ProjectLine(0,0,0,GridSize,0,0,255,0,0) ; X Line
	ProjectLine(0,0,0,0,GridSize,0,0,255,0) ; Y Line
	ProjectLine(0,0,0,0,0,GridSize,0,0,255) ; Z Line
	
	Local TempX#[3]
	Local TempZ#[3]
	Local TempPZ#[3]
	
	Color 255,0,0
	
	For pos# = 0 To GridSize*(GridSpace^-1) ; Instead of doing GridSize/GridSpace which freezes the program if either are 0
											; The smaller the GridSpace, the more points/dots there are
		
		TempSpacing# = GridSpace*pos
		
		If TempSpacing <= GridSize
			ProjectPoint(TempSpacing,0,TempSpacing,TempSpacing,255)
			ProjectPoint(TempSpacing,0,-TempSpacing,TempSpacing,255)
			ProjectPoint(-TempSpacing,0,TempSpacing,TempSpacing,255)
			ProjectPoint(-TempSpacing,0,-TempSpacing,TempSpacing,255)
		EndIf
	Next
	
	Color 0,255,0
	
	Text 0,40,"Points = " + TempPoints
	
	Color 0,0,0
	Text 0,80,"Center Cube depth = " + MeshDepth(cube[0])
	Text 0,100,"Smaller Cube X position = " + EntityX(cube[1])
	Text 0,120,"Grid Size " + GridSize
	Text 0,140,"Grid Space " + GridSpace
	Text 0,160,"Press T and G to change the Grid Size"
	Text 0,180,"Press Y and H to change the Grid Space"
	
	
	Flip
Wend
ClearWorld 1,1,1
End

Function ProjectPoint(x#,y#,z#,value$="",point_red%=0,point_green%=0,point_blue%=0)
	CameraProject Camera,x,y,z
	
	If ProjectedZ() > 0
		
		RectSize# = Sqr(EntityX(Camera,1)^2+EntityY(Camera,1)^2+EntityZ(Camera,1)^2 + x^2 + y^2 + z^2)
		RectSize = Cos(RectSize)*4
		
		If RectSize > 0
			TempX# = ProjectedX()
			TempY# = ProjectedY()
			Color point_red,point_green,point_blue
			Rect TempX,TempY,RectSize,RectSize
			Color 250,250,0
			Text TempX,TempY,value
			TempPoints = TempPoints + 1
		EndIf
	EndIf
	
	Return ProjectedZ()
End Function

Function ProjectLine(x1#,y1#,z1#,x2#,y2#,z2#,line_red%=0,line_green%=0,line_blue%=0)
	TempPivot1% = CreatePivot()
		PositionEntity TempPivot1,x1,y1,z1,1
	
	TempPivot2% = CreatePivot()
		PositionEntity TempPivot2,x2,y2,z2,1
	
	TempX1#=0
	TempY1#=0
	
	TempX2#=0
	TempY2#=0
	
	
	If EntityInView(TempPivot1,Camera)
		If EntityInView(TempPivot2,Camera)
			CameraProject Camera,x1,y1,z1
			
				TempX1 = ProjectedX()
				TempY1 = ProjectedY()
				
			CameraProject Camera,x2,y2,z2
			
				TempX2 = ProjectedX()
				TempY2 = ProjectedY()
			
			Color line_red,line_green,line_blue
			Line TempX1,TempY1,TempX2,TempY2
		EndIf
	EndIf
	
	FreeEntity TempPivot1
	FreeEntity TempPivot2
	
End Function

Function CreateGridTexture(flags%)
	Local gtexture = CreateTexture(32,32,flags)
	
	SetBuffer TextureBuffer(gtexture)
	Color 0,0,0
	Rect 0,0,32,32
	
	Color 90,90,90
	Line 16,0,16,32
	Line 0,16,32,16
	
	SetBuffer BackBuffer()
	
	Return gtexture
End Function

Function DrawWorld()
	UpdateWorld
	RenderWorld
End Function

Function InitGraphics(width = 800, height = 600,title$="Blitz3D Program",exit_message$="Are you sure?")
	Graphics3D width, height, 32, 2
	SetBuffer BackBuffer()
	SeedRnd MilliSecs()
	AppTitle title,exit_message
End Function

The grid spacing shouldn't matter whether its 1002.5125 or 2.9.
The grid size is the border and should limit how many dots are made/displayed.

Here is what it should look like on paper (note, I made this the day BEFORE Pongo posted the idea)


The number above each grid is the grid size, the one to the right is the grid space. The grids on the the right side of the page are all a grid space of 2.