LightMapping Techniques

I been experimenting with Lightmaps, just started out, so if any expert out there, feel free to drop some advice or two ;)

My engine is made up by block tiles


If i want to make in-built function that light map this, should i add all those tiles into one giant mesh or lightmap it as separate tiles? Which way would be faster or better?

Nack

Here is what ive done in the past. For all static objects in the level... dynamic entities I use entity color.

I have all of my building blocks as OBJ type with position rotation etc. Then I have a type called SECTION. The section is a final mesh built and light mapped. I create a temp copy of each object called a LMOBJ for light mapped objects. Position them into place, add them to a newly created mesh, and then unweld and light map it with YAL(yet another light mapper found in the code archives. If you play with YAL you'll notice the functions being called here. Its kinda a rough way to do things, but it works for me. So for the editor I just have a toggle that Show_final_meshes if true then hide the building blocks and vice versa.

Include "source\ray_intersect.bb"

Function light_map(section%)

first_selection = False

	For O.obj=Each obj
	
		If O\zone% = section% Then
		
			LM.lm_obj=New lm_obj
			LM\entity = CopyMesh (block(O\part%))

			LM\X# = O\X#
			LM\Y# = O\Y#
			LM\Z# = O\Z#
			LM\RX# = O\RX#
			LM\RY# = O\RY#
			LM\RZ# = O\RZ#

			LM\texture% = O\texture%
	
			EntityFX LM\entity,1
			PaintMesh LM\entity,brush_texture( LM\texture% )
			RotateMesh LM\entity, LM\RX#, LM\RY#, LM\RZ#
			PositionMesh LM\entity, LM\X#, LM\Y#, LM\Z#
			EntityPickMode LM\entity,2

		If first_selection = False Then 
			PositionEntity temp_piv,EntityX(O\entity),EntityY(O\entity),EntityZ(O\entity)
			first_selection = True
		End If

			last_x# = O\X#
			last_y# = O\y#
			last_z# = O\z#

		End If
	
	Next

	If first_selection=False Then Return

	For S.section = Each section 
	
		If S\number% = section% Then 
	
			FreeEntity S\mesh
			S\mesh = CreateMesh()
			NameEntity( S\mesh, S\number% )
			

			For N.lm_obj = Each lm_obj
		
					AddMesh N\entity,S\mesh
		
			Next
	
			ThisObscurer.LMObscurer = New LMObscurer
			ThisObscurer\Entity = S\mesh
	
			BeginLightMap(Ambient_r%, Ambient_g%, Ambient_b%)
					
			For L.light= Each light
			
				If L\zone% = section%
			
					CreateLMLight( L\X#, L\Y#, L\Z#, L\R%,L\G%,L\B%, L\range%, False, L\brightness%)
			
				End If
			Next
	
			tex = LightMapMesh(S\mesh, 2.0, 256, 0, "Lightmapping " + EntityName(S\mesh))
	
			lm_folder$ = "maps" + map_name$ + ""
	
			If tex
				SaveLightMap(S\mesh, tex, lm_folder$ + EntityName(S\mesh) + ".bmp", lm_folder$ + EntityName(S\mesh) + ".luv")
				ApplyLightMap(S\mesh, tex)
			EndIf
					
			EndLightMap()
	
			For R.lm_obj=Each lm_obj
				FreeEntity R\entity
				Delete R
			Next


			For M.LMLight= Each LMLight
			
				Delete M
			
			Next

			If Show_final_meshes = -1 Then HideEntity S\mesh
			
		End If
	
	Next


End Function