dot 3 lighting

Blitz3D Forums/Blitz3D Programming/dot 3 lighting

Neochrome

(Posted 2004) [#1]

How can i make a Dot3 object be independent to the light?

i meam, a cube is spinning but the light source it self stays where it is, but the normal light colours alter?

AntonyWells

(Posted 2004) [#2]

You need to transpose it into the object's space.

tformpoint lightX,lightY,lightZ,entityToLight,0

positionLight tformedX(),tformedY(),tformedZ()

then get the vector from the tformed position.(Remember move the light back, or just work directly on the tform funcs.)

Neochrome

(Posted 2004) [#3]

any code? this could be SO cool to have DirectX 7 to do Some Dot3 stuff. only stuff like crates and pipes tho in the long run its prolly just as fast to make the polys in DX7! hehe

but have you got any example code that would work? its 3am in the morning, my heads gone to sleep :(

AntonyWells

(Posted 2004) [#4]

Function entityLight(entity,light,inten#=0.5,hull=False)
ox#=EntityX(light)
oy#=EntityY(light)
oz#=EntityZ(light)
inten =0.5
;If Not hull inten=1.-inten
tp=CreatePivot()
PositionEntity tp,EntityX(light),EntityY(light),EntityZ(light)
TFormPoint ox,oy,oz,tp,entity
;FreeEntity tp
light=tp

PositionEntity light,TFormedX(),TFormedY(),TFormedZ() ;Transpose light into 
dx# =(EntityX(light)-EntityX( entity));*inten
dy# =(EntityY(light)-EntityY( entity));*inten
dz# =(EntityZ(light)-EntityZ( entity));*inten

nl#=Sqr(dx*dx+dy*dy+dz*dz)
nx#=dx/nl
ny#=dy/nl
nz#=dz/nl
nl#=(nl*10.-255.)/255.

nl=1.-nl

If nl>1. nl=1
If nl<0. nl=0
nl=in

nx=nx;*inten
ny=ny;*inten
nz=nz;*inten

;nz=(Sgn(nz))+nz
;nx=(Sgn(nx))+nx
;ny=(Sgn(ny))+ny

;If nx<0 nx


FreeEntity tp
EntityColor entity,128.+(128.*nx),128.+(128.*nz),128.+(128.*ny)


;EntityColor entity,256+(256*nx),256.0+(256*ny),256.0+(256*nt)

;PositionEntity light,ox,oy,oz ;return light.
End Function

ripped it from some old code of mine..could do with cleaning up a little, but it worked fine for me. Light = light pivot, entity =entity to light, inten =light strength, hull=internal or exteneral.

Neochrome

(Posted 2004) [#5]

hmm, this seems to be working the oposite way, the light is in front of the object, and im getting the effect on the other side.

also, its not working verywell on objects that move :(

AntonyWells

(Posted 2004) [#6]

If the light's on the wrong side, just reverse the vector.

As for not working on moving objects, it did for me way back when. Upload something simple showing me what you mean and i'll try to fix it anyway.

Neochrome

(Posted 2004) [#7]

here is the code
im trying to grasp the concept, I got the normal mapping program from nvedia, Nice kit, so i need Blitz to utilise it properly. i'll be moving about the map and the boxes are bumped

Global camera,worldpivot
Global campitch#,camyaw#,mvx#,mvy#,mvz#,temp#,vx#,vy#,vz#



Graphics3D 1024,768,0,2
MoveMouse 1024/2,768/2
FlushMouse
SetBuffer BackBuffer( )
If GfxDriverCaps3D()<110 Then RuntimeError "Sorry, your graphics card does not support cubic environment maps."

;camera
camera = CreateCamera( )
PositionEntity camera, 0, 2, -16


;load model
model = LoadMesh("box_1.b3d")
;model = CreateCube()

;RotateMesh model,-90,0,0

PositionEntity model,0,0,0
ScaleEntity model,.1,.1,.1
EntityFX model,1

normaltex = LoadTexture("ibox_norm.bmp",0)
TextureBlend normaltex,4
EntityTexture model, normaltex,0,0


pivot=CreatePivot()
mylight = CreateSphere(2)
light=CreateLight(1,mylight)
LightRange light,200

ScaleEntity mylight,0.1,0.1,0.1
EntityFX mylight,1
PositionEntity mylight,0,0,-8

AmbientLight 100,100,100

norm=1

While Not KeyHit( 1 )

	If KeyHit(57)
		norm=1-norm
		If norm=1
			ShowEntity model
			HideEntity lomodel
		Else
			ShowEntity lomodel
			HideEntity model		
		EndIf
	EndIf

	;PointEntity camera,model
	;MoveEntity camera,.01,0,0
	;TurnEntity camera,-20,0,0

freelook


	If KeyDown(203) Then TurnEntity(model,0,3.1,0)
	If KeyDown(205) Then TurnEntity(model,0,-3.1,0)

	;mylight
	rot#=rot#+1.5
	
	rrot = EntityYaw(model)
	
	xrot#=Cos(rot)*8
	zrot#=Sin(rot)*8
	yrot#=Cos(rot/2)*8
	PointEntity mylight,model	
	PositionEntity mylight,EntityX(model)+xrot,EntityY(model) + yrot,EntityZ(model)+zrot

	;the dot3 light

	
	PositionEntity pivot, EntityX(model),EntityY(model),EntityZ(model)
	RotateEntity pivot,EntityPitch(mylight),EntityYaw(mylight)+180,0


	
	MoveEntity pivot, 0, 0, 1


	doty# = (EntityY(model)) - EntityY(pivot)

	; then work out the Light possitions :)


	AppTitle dotx


	r#=(EntityX(pivot)+1.0) * 128.0
	g#=(-EntityZ(pivot)+1.0) * 128.0
	b#=(-doty+1.0) * 128.0


	;EntityColor model,r,g,b


	;NormalMapMesh model,0,10,10,0


	entityLight model,mylight,1.6,False
	
	UpdateWorld
	RenderWorld
	
	Text 1024/2,768-16,"- Hit space to toggle -",1,1
	
	If norm
		Text 0,0,"68,176 simulated polygons with normal mapping."
	Else
		Text 0,0,"802 polygons."
	EndIf
	
	Flip
Wend
End


;camera freelook
Function freelook()
	mxspd#=MouseXSpeed()*0.25
	myspd#=MouseYSpeed()*0.25
	;MoveMouse GraphicsWidth()/2,GraphicsHeight()/2
	campitch=campitch+myspd
	If campitch<-85 Then campitch=-85
	If campitch>85 Then campitch=85
	RotateEntity camera,campitch,EntityYaw(camera)-mxspd,0
	;If KeyDown(203) Then mvx=mvx-.3
	;If KeyDown(205) Then mvx=mvx+.3


	
	If KeyDown(200) Then mvz=mvz+.3
	If KeyDown(208) Then mvz=mvz-.3
	If KeyDown(30) Then mvx=mvx-.3
	If KeyDown(32) Then mvx=mvx+.3
	If KeyDown(17) Then mvz=mvz+.3
	If KeyDown(31) Then mvz=mvz-.3
	mvx#=mvx*.8
	mvy#=mvy*.8
	mvz#=mvz*.8
	MoveEntity camera,mvx,mvy,mvz
End Function

Function entityLight(entity,light,inten#=0.5,hull=False)
ox#=EntityX(light)
oy#=EntityY(light)
oz#=EntityZ(light)
;inten =0.5
If Not hull inten=1.-inten
tp=CreateCube()
PositionEntity tp,EntityX(light),EntityY(light),EntityZ(light)
TFormPoint ox,oy,oz,tp,entity
;FreeEntity tp
light=tp
PositionEntity light,TFormedX(),TFormedY(),TFormedZ() ;Transpose light into 
dx# =(EntityX(light)-EntityX( entity));*inten
dy# =(EntityY(light)-EntityY( entity));*inten
dz# =(EntityZ(light)-EntityZ( entity));*inten
nl#=Sqr(dx*dx+dy*dy+dz*dz)
nx#=dx/nl
ny#=dy/nl
nz#=dz/nl
nl#=(nl*10.-255.)/255.
nl=1.-nl
If nl>1. nl=1
If nl<0. nl=0
nl=in
nx=nx*inten
ny=ny*inten
nz=nz*inten
;nz=(Sgn(nz))+nz
;nx=(Sgn(nx))+nx
;ny=(Sgn(ny))+ny
;If nx<0 nx
;FreeEntity tp
;EntityColor entity,128.+(128.*nx),128.+(128.*nz),128.+(128.*ny)
EntityColor entity,128.+(128.*nx),128.+(128.*ny),128.+(128.*nz)
;EntityColor entity,256+(256*nx),256.0+(256*ny),256.0+(256*nz)
;PositionEntity light,ox,oy,oz ;return light.
End Function



Function NormalMapMesh(mesh,x#=-1,y#=-1,z#=1,style=0)
If EntityClass(mesh)="Mesh"
	temp=CreatePivot()
	If style=0
		AlignToVector temp,x,y,z,3
		RotateEntity temp,EntityPitch(temp),EntityYaw(temp),0
		EndIf
	For s=1 To CountSurfaces(mesh)
		surf=GetSurface(mesh,s)
		For v=0 To CountVertices(surf)-1
			Select style
				;Directional light
				Case 0
					TFormNormal VertexNX(surf,v),VertexNY(surf,v),VertexNZ(surf,v),mesh,temp
					r#=(1.0-TFormedX())*127.5
					g#=(1.0-TFormedY())*127.5
					b#=(1.0-TFormedZ())*127.5
					If TFormedZ()>0 b=0
				;Point light
				Case 1
					RotateEntity temp,0,0,0
					TFormPoint VertexX(surf,v),VertexY(surf,v),VertexZ(surf,v),mesh,temp
					AlignToVector temp,TFormedX(),TFormedY(),TFormedZ(),3
					RotateEntity temp,EntityPitch(temp),EntityYaw(temp),0
					TFormNormal VertexNX(surf,v),VertexNY(surf,v),VertexNZ(surf,v),mesh,temp	
					r#=(1.0-TFormedX())*127.5
					g#=(1.0-TFormedY())*127.5
					b#=(1.0-TFormedZ())*127.5
					If TFormedZ()>0 b=0
					TFormPoint VertexX(surf,v),VertexY(surf,v),VertexZ(surf,v),mesh,temp
					d#=PointDistance(TFormedX(),TFormedY(),TFormedZ(),0,0,0)
					range#=200
					If d<range
						d#=Sqr((range-d)/range)
						b#=d*255
						Else
						b=0
						EndIf
				End Select
			VertexColor surf,v,r,g,b
			Next
		Next
	FreeEntity temp
	EndIf
For c=1 To CountChildren(mesh)
	normalmapmesh GetChild(mesh,c)
	Next
End Function

Function PointDistance#(Ax#,Ay#,Az#,Bx#,By#,Bz#) 
Return Sqr((ax-bx)^2.0+(ay-by)^2.0+(az-bz)^2.0) 
End Function

the media files are

http://www.neomancer.co.uk/ibox_norm.zip