[bb] Bezier Patches - Editable 3D surfaces. by Jeppe Nielsen [ 1+ years ago ]

[BlitzBot]

Title : Bezier Patches - Editable 3D surfaces.
Author : Jeppe Nielsen
Posted : 1+ years ago

Description : Shows how bezier patches can be created, example demonstrates an interactive 3d surface.

Code :

Code (blitzbasic) Select Expand

;*****************************************************
;*               Bezier Patch example                *
;*****************************************************
;*              By Jeppe Nielsen 2005                *
;*****************************************************
;*                jeppe@gameart.dk                   *
;*****************************************************

Graphics3D 800,600

segments=10

b.bezierpatch = BezierPatchNew()

patch=BezierPatchMesh(b,segments,segments)

patchtexture=CreateTexture(32,32)
SetBuffer TextureBuffer(patchtexture)
ClsColor 255,0,0
Cls
Color 255,255,255
Rect 0,0,16,16,True
Rect 16,16,16,16,True

SetBuffer BackBuffer()

ScaleTexture patchtexture,0.25,0.25
EntityTexture patch,patchtexture

Global camera,camerarx#,camerary#

CameraInit

light=CreateLight(2)
PositionEntity light,0,10,0
LightRange light,5



plane=CreatePlane()
EntityPickMode plane,2
EntityAlpha plane,0

selectedpoint=-1

Repeat

cameraupdate 0.1

Select state

Case 0

If MouseDown(1)
selectedpoint=BezierPatchGetPoint(b,camera,MouseX(),MouseY())
If selectedpoint<>-1
state=1
PositionEntity plane,bpx[selectedpoint],bpy[selectedpoint],bpz[selectedpoint]
EndIf
EndIf

Case 1

If MouseDown(1)

CameraPick(camera,MouseX(),MouseY())

BezierPatchSetPoint(b,selectedpoint,PickedX#(),PickedY#(),PickedZ#())
If patch<>0
FreeEntity patch
patch=0
EndIf

patch=BezierPatchMesh(b,segments,segments)
EntityTexture patch,patchtexture

Else

state=0

EndIf

End Select

If selectedpoint<>-1

If KeyDown(201)

bpy[selectedpoint]=bpy[selectedpoint]+0.5
If patch<>0
FreeEntity patch
patch=0
EndIf

patch=BezierPatchMesh(b,segments,segments)
EntityTexture patch,patchtexture


ElseIf KeyDown(209)

bpy[selectedpoint]=bpy[selectedpoint]-0.5
If patch<>0
FreeEntity patch
patch=0
EndIf

patch=BezierPatchMesh(b,segments,segments)
EntityTexture patch,patchtexture


EndIf


EndIf

If KeyHit(78)

segments=segments+1
If patch<>0
FreeEntity patch
patch=0
EndIf

patch=BezierPatchMesh(b,segments,segments)
EntityTexture patch,patchtexture


ElseIf KeyHit(74)

segments=segments-1
If segments<1
segments=1
EndIf
If patch<>0
FreeEntity patch
patch=0
EndIf

patch=BezierPatchMesh(b,segments,segments)
EntityTexture patch,patchtexture

EndIf

If KeyHit(57)

wire=1-wire
WireFrame wire

EndIf


RenderWorld

Color 0,0,255
BezierPatchDraw(b,camera,selectedpoint)

Color 0,0,0
Text 401,11,"Bezier Patch example by Jeppe Nielsen, 2005",True
Text 401,31,"Left mouse button to move control points",True
Text 401,51,"Right mouse button & mouse to rotate camera, cursor keys to move camera",True
Text 401,71,"Page Up/down to move selected control point up/down",True
Text 401,91,"+ / - to adjust polygon segments : "+segments,True
Text 401,111,"Space to toggle wireframe",True

Color 0,128,255
Text 400,10,"Bezier Patch example by Jeppe Nielsen, 2005",True
Text 400,30,"Left mouse button to move control points",True
Text 401,51,"Right mouse button & mouse to rotate camera, cursor keys to move camera",True
Text 400,70,"Page Up/down to move selected control point up/down",True
Text 400,90,"+ / - to adjust polygon segments : "+segments,True
Text 400,110,"Space to toggle wireframe",True

x=MouseX()
y=MouseY()

Color 255,255,255

Rect x-6,y,13,1
Rect x,y-6,1,13


Flip

Until KeyDown(1)
End


Type bezierpatch

Field px#[15]
Field py#[15]
Field pz#[15]

End Type

Function BezierPatchNew.bezierpatch()

b.bezierpatch=New bezierpatch

For u=0 To 3

For v=0 To 3

bpx[u+v*4]=u*3
bpy[u+v*4]=0
bpz[u+v*4]=v*3

Next

Next

Return b
End Function

Function BezierPatchSetPoint(b.bezierpatch,point,x#,y#,z#)

bpx[point]=x
bpy[point]=y
bpz[point]=z

End Function

Function BezierPatchGetPoint(b.bezierpatch,cam,x,y,size=15)

sizesq=size*size

For n=0 To 15

CameraProject cam,bpx[n],bpy[n],bpz[n]

dx=x-ProjectedX()
dy=y-ProjectedY()

dist=dx*dx+dy*dy

If dist<=sizesq
Return n
EndIf

Next

Return -1
End Function

Function BezierPatchMesh(b.bezierpatch,useg=10,vseg=10)

mesh=CreateMesh()

surf=CreateSurface(mesh)

usegstep#=1/Float(useg)
vsegstep#=1/Float(vseg)

v#=0

While v<0.99

u#=0

While u<0.99

uu#=u

px1#=bpx[0]*(1-uu)^3 + bpx[1]*3*(1-uu)^2*uu + bpx[2]*3*(1-uu)*uu*uu + bpx[3]*uu^3
py1#=bpy[0]*(1-uu)^3 + bpy[1]*3*(1-uu)^2*uu + bpy[2]*3*(1-uu)*uu*uu + bpy[3]*uu^3
pz1#=bpz[0]*(1-uu)^3 + bpz[1]*3*(1-uu)^2*uu + bpz[2]*3*(1-uu)*uu*uu + bpz[3]*uu^3

px2#=bpx[4]*(1-uu)^3 + bpx[5]*3*(1-uu)^2*uu + bpx[6]*3*(1-uu)*uu*uu + bpx[7]*uu^3
py2#=bpy[4]*(1-uu)^3 + bpy[5]*3*(1-uu)^2*uu + bpy[6]*3*(1-uu)*uu*uu + bpy[7]*uu^3
pz2#=bpz[4]*(1-uu)^3 + bpz[5]*3*(1-uu)^2*uu + bpz[6]*3*(1-uu)*uu*uu + bpz[7]*uu^3

px3#=bpx[8]*(1-uu)^3 + bpx[9]*3*(1-uu)^2*uu + bpx[10]*3*(1-uu)*uu*uu + bpx[11]*uu^3
py3#=bpy[8]*(1-uu)^3 + bpy[9]*3*(1-uu)^2*uu + bpy[10]*3*(1-uu)*uu*uu + bpy[11]*uu^3
pz3#=bpz[8]*(1-uu)^3 + bpz[9]*3*(1-uu)^2*uu + bpz[10]*3*(1-uu)*uu*uu + bpz[11]*uu^3

px4#=bpx[12]*(1-uu)^3 + bpx[13]*3*(1-uu)^2*uu + bpx[14]*3*(1-uu)*uu*uu + bpx[15]*uu^3
py4#=bpy[12]*(1-uu)^3 + bpy[13]*3*(1-uu)^2*uu + bpy[14]*3*(1-uu)*uu*uu + bpy[15]*uu^3
pz4#=bpz[12]*(1-uu)^3 + bpz[13]*3*(1-uu)^2*uu + bpz[14]*3*(1-uu)*uu*uu + bpz[15]*uu^3

vv#=v

x1# = px1*(1-vv)^3 + 3*px2*(1-vv)^2*vv + 3*px3*(1-vv)*vv*vv + px4*vv^3
y1# = py1*(1-vv)^3 + 3*py2*(1-vv)^2*vv + 3*py3*(1-vv)*vv*vv + py4*vv^3
z1# = pz1*(1-vv)^3 + 3*pz2*(1-vv)^2*vv + 3*pz3*(1-vv)*vv*vv + pz4*vv^3

uu#=u+usegstep

px1#=bpx[0]*(1-uu)^3 + bpx[1]*3*(1-uu)^2*uu + bpx[2]*3*(1-uu)*uu*uu + bpx[3]*uu^3
py1#=bpy[0]*(1-uu)^3 + bpy[1]*3*(1-uu)^2*uu + bpy[2]*3*(1-uu)*uu*uu + bpy[3]*uu^3
pz1#=bpz[0]*(1-uu)^3 + bpz[1]*3*(1-uu)^2*uu + bpz[2]*3*(1-uu)*uu*uu + bpz[3]*uu^3

px2#=bpx[4]*(1-uu)^3 + bpx[5]*3*(1-uu)^2*uu + bpx[6]*3*(1-uu)*uu*uu + bpx[7]*uu^3
py2#=bpy[4]*(1-uu)^3 + bpy[5]*3*(1-uu)^2*uu + bpy[6]*3*(1-uu)*uu*uu + bpy[7]*uu^3
pz2#=bpz[4]*(1-uu)^3 + bpz[5]*3*(1-uu)^2*uu + bpz[6]*3*(1-uu)*uu*uu + bpz[7]*uu^3

px3#=bpx[8]*(1-uu)^3 + bpx[9]*3*(1-uu)^2*uu + bpx[10]*3*(1-uu)*uu*uu + bpx[11]*uu^3
py3#=bpy[8]*(1-uu)^3 + bpy[9]*3*(1-uu)^2*uu + bpy[10]*3*(1-uu)*uu*uu + bpy[11]*uu^3
pz3#=bpz[8]*(1-uu)^3 + bpz[9]*3*(1-uu)^2*uu + bpz[10]*3*(1-uu)*uu*uu + bpz[11]*uu^3

px4#=bpx[12]*(1-uu)^3 + bpx[13]*3*(1-uu)^2*uu + bpx[14]*3*(1-uu)*uu*uu + bpx[15]*uu^3
py4#=bpy[12]*(1-uu)^3 + bpy[13]*3*(1-uu)^2*uu + bpy[14]*3*(1-uu)*uu*uu + bpy[15]*uu^3
pz4#=bpz[12]*(1-uu)^3 + bpz[13]*3*(1-uu)^2*uu + bpz[14]*3*(1-uu)*uu*uu + bpz[15]*uu^3

vv#=v

x2# = px1*(1-vv)^3 + 3*px2*(1-vv)^2*vv + 3*px3*(1-vv)*vv*vv + px4*vv^3
y2# = py1*(1-vv)^3 + 3*py2*(1-vv)^2*vv + 3*py3*(1-vv)*vv*vv + py4*vv^3
z2# = pz1*(1-vv)^3 + 3*pz2*(1-vv)^2*vv + 3*pz3*(1-vv)*vv*vv + pz4*vv^3

uu#=u

px1#=bpx[0]*(1-uu)^3 + bpx[1]*3*(1-uu)^2*uu + bpx[2]*3*(1-uu)*uu*uu + bpx[3]*uu^3
py1#=bpy[0]*(1-uu)^3 + bpy[1]*3*(1-uu)^2*uu + bpy[2]*3*(1-uu)*uu*uu + bpy[3]*uu^3
pz1#=bpz[0]*(1-uu)^3 + bpz[1]*3*(1-uu)^2*uu + bpz[2]*3*(1-uu)*uu*uu + bpz[3]*uu^3

px2#=bpx[4]*(1-uu)^3 + bpx[5]*3*(1-uu)^2*uu + bpx[6]*3*(1-uu)*uu*uu + bpx[7]*uu^3
py2#=bpy[4]*(1-uu)^3 + bpy[5]*3*(1-uu)^2*uu + bpy[6]*3*(1-uu)*uu*uu + bpy[7]*uu^3
pz2#=bpz[4]*(1-uu)^3 + bpz[5]*3*(1-uu)^2*uu + bpz[6]*3*(1-uu)*uu*uu + bpz[7]*uu^3

px3#=bpx[8]*(1-uu)^3 + bpx[9]*3*(1-uu)^2*uu + bpx[10]*3*(1-uu)*uu*uu + bpx[11]*uu^3
py3#=bpy[8]*(1-uu)^3 + bpy[9]*3*(1-uu)^2*uu + bpy[10]*3*(1-uu)*uu*uu + bpy[11]*uu^3
pz3#=bpz[8]*(1-uu)^3 + bpz[9]*3*(1-uu)^2*uu + bpz[10]*3*(1-uu)*uu*uu + bpz[11]*uu^3

px4#=bpx[12]*(1-uu)^3 + bpx[13]*3*(1-uu)^2*uu + bpx[14]*3*(1-uu)*uu*uu + bpx[15]*uu^3
py4#=bpy[12]*(1-uu)^3 + bpy[13]*3*(1-uu)^2*uu + bpy[14]*3*(1-uu)*uu*uu + bpy[15]*uu^3
pz4#=bpz[12]*(1-uu)^3 + bpz[13]*3*(1-uu)^2*uu + bpz[14]*3*(1-uu)*uu*uu + bpz[15]*uu^3

vv#=v+vsegstep

x3# = px1*(1-vv)^3 + 3*px2*(1-vv)^2*vv + 3*px3*(1-vv)*vv*vv + px4*vv^3
y3# = py1*(1-vv)^3 + 3*py2*(1-vv)^2*vv + 3*py3*(1-vv)*vv*vv + py4*vv^3
z3# = pz1*(1-vv)^3 + 3*pz2*(1-vv)^2*vv + 3*pz3*(1-vv)*vv*vv + pz4*vv^3

uu#=u+usegstep

px1#=bpx[0]*(1-uu)^3 + bpx[1]*3*(1-uu)^2*uu + bpx[2]*3*(1-uu)*uu*uu + bpx[3]*uu^3
py1#=bpy[0]*(1-uu)^3 + bpy[1]*3*(1-uu)^2*uu + bpy[2]*3*(1-uu)*uu*uu + bpy[3]*uu^3
pz1#=bpz[0]*(1-uu)^3 + bpz[1]*3*(1-uu)^2*uu + bpz[2]*3*(1-uu)*uu*uu + bpz[3]*uu^3

px2#=bpx[4]*(1-uu)^3 + bpx[5]*3*(1-uu)^2*uu + bpx[6]*3*(1-uu)*uu*uu + bpx[7]*uu^3
py2#=bpy[4]*(1-uu)^3 + bpy[5]*3*(1-uu)^2*uu + bpy[6]*3*(1-uu)*uu*uu + bpy[7]*uu^3
pz2#=bpz[4]*(1-uu)^3 + bpz[5]*3*(1-uu)^2*uu + bpz[6]*3*(1-uu)*uu*uu + bpz[7]*uu^3

px3#=bpx[8]*(1-uu)^3 + bpx[9]*3*(1-uu)^2*uu + bpx[10]*3*(1-uu)*uu*uu + bpx[11]*uu^3
py3#=bpy[8]*(1-uu)^3 + bpy[9]*3*(1-uu)^2*uu + bpy[10]*3*(1-uu)*uu*uu + bpy[11]*uu^3
pz3#=bpz[8]*(1-uu)^3 + bpz[9]*3*(1-uu)^2*uu + bpz[10]*3*(1-uu)*uu*uu + bpz[11]*uu^3

px4#=bpx[12]*(1-uu)^3 + bpx[13]*3*(1-uu)^2*uu + bpx[14]*3*(1-uu)*uu*uu + bpx[15]*uu^3
py4#=bpy[12]*(1-uu)^3 + bpy[13]*3*(1-uu)^2*uu + bpy[14]*3*(1-uu)*uu*uu + bpy[15]*uu^3
pz4#=bpz[12]*(1-uu)^3 + bpz[13]*3*(1-uu)^2*uu + bpz[14]*3*(1-uu)*uu*uu + bpz[15]*uu^3

vv#=v+vsegstep

x4# = px1*(1-vv)^3 + 3*px2*(1-vv)^2*vv + 3*px3*(1-vv)*vv*vv + px4*vv^3
y4# = py1*(1-vv)^3 + 3*py2*(1-vv)^2*vv + 3*py3*(1-vv)*vv*vv + py4*vv^3
z4# = pz1*(1-vv)^3 + 3*pz2*(1-vv)^2*vv + 3*pz3*(1-vv)*vv*vv + pz4*vv^3


vert=AddVertex(surf,x1,y1,z1,u,v)
    AddVertex(surf,x2,y2,z2,u+usegstep,v)
    AddVertex(surf,x3,y3,z3,u,v+vsegstep)
    AddVertex(surf,x4,y4,z4,u+usegstep,v+vsegstep)

AddTriangle surf,vert+0,vert+3,vert+1
AddTriangle surf,vert+0,vert+2,vert+3

u=u+usegstep

Wend

v=v+vsegstep

Wend

UpdateNormals mesh

Return mesh
End Function

Function BezierPatchDraw(b.bezierpatch,cam,selectedpoint)

Local projx[15],projy[15]

For n=0 To 15

CameraProject cam,bpx[n],bpy[n],bpz[n]

projx[n]=ProjectedX()
projy[n]=ProjectedY()

If selectedpoint=n

Color 255,255,0

Else

Color 0,0,255

EndIf

Oval projx[n]-5,projy[n]-5,10,10,True


Next

Color 0,255,0

For u=0 To 3

For v=0 To 3
If u<3
Line projx[u+v*4],projy[u+v*4],projx[u+v*4+1],projy[u+v*4+1]
EndIf
If v<3
Line projx[u+v*4],projy[u+v*4],projx[u+v*4+4],projy[u+v*4+4]
EndIf

Next

Next

End Function

Function CameraInit(r=0,g=0,b=0,x#=12,y#=10,z#=12,px#=0,py#=0,pz#=0)

camera=CreateCamera()
CameraClsColor camera,r,g,b
PositionEntity camera,x,y,z
p=CreatePivot()
PositionEntity p,px,py,pz
PointEntity camera,p
FreeEntity p
MoveMouse GraphicsWidth()/2,GraphicsHeight()/2
camerarx=EntityPitch(camera)
camerary=EntityYaw(camera)

End Function

Function CameraClear()

If camera<>0 Then FreeEntity camera : camera=0

End Function

Function CameraUpdate(speed#=1)


If MouseHit(2)

MoveMouse GraphicsWidth()/2,GraphicsHeight()/2

EndIf

If MouseDown(2)

camerarx#=camerarx#+MouseYSpeed()*0.5
camerary#=camerary#-MouseXSpeed()*0.5
If camerarx#>89
camerarx#=89
ElseIf camerarx#<-89
camerarx#=-89
EndIf
RotateEntity camera,camerarx,camerary,0
MoveMouse GraphicsWidth()/2,GraphicsHeight()/2

EndIf

If KeyDown(200) Or KeyDown(17) Then MoveEntity camera,0,0,speed#
If KeyDown(208) Or KeyDown(31) Then MoveEntity camera,0,0,-speed#
If KeyDown(203) Or KeyDown(30) Then MoveEntity camera,-speed#,0,0
If KeyDown(205) Or KeyDown(32) Then MoveEntity camera,speed#,0,0

End Function

Comments :


BlitzSupport(Posted 1+ years ago)

 Very cool indeed -- only thing is you have to run windowed as there's no pointer in full-screen mode! The resulting meshes look great though.


Jeppe Nielsen(Posted 1+ years ago)

 Yes I forgot to include a pointer as I was creating this in windowed mode :-)I have updated the code now.


Barliesque(Posted 1+ years ago)

 Looking forward to seeing this when I get home to my own computer... for now, I'm wondering if this might be a basis for supporting models from Hash Animation:Master--which is patch-based.


WarpZone(Posted 1+ years ago)

 Wow.  This is great.  This explains all those terrain programs that suddenly appeared simultaneously. =)  Now if only I UNDERSTOOD enough of what was going on here to make it *scalable.*