another Mesh Vertex Position and color example

applePi · Post by **applePi** » Sat Sep 14, 2013 9:23 am

another adaptation of the code posted here http://www.purebasic.fr/english/viewtop ... 94#p425025 , the purpose is to plot 100000 random points inside a cube, and a certain area in the center are plotted in blue
r=0:g=0:b=255
MeshVertexColor(RGBA(r,g,b,100))
now after filling the MeshData with points positions and its colours, i want to isolate the blue points only

Code: Select all

Procedure isolate()
   For i=0 To 100000
     If MeshData(i)\Color = RGBA(255,0,0,100)
       MeshData(i)\x+1
       MeshData(i)\y+1
       
       
     EndIf
   Next
   SetMeshData(0,0, MeshData(), #PB_Mesh_Vertex, 0, MeshVertexCount(0)-1)
   
 EndProcedure

note the RGBA(255,0,0,100) , isn't should be RGBA(0,0,255,100) because i have saved the blue points as RGBA(0,0,255,100) ??

Code: Select all

Enumeration
   #MESH
   #LIGHT
   #CAMERA
   #mainwin
 EndEnumeration
Structure Vector3
  x.f
  y.f
  z.f
EndStructure
Define.Vector3 v1, v2, v3 


Global x.f = 0
Global y.f = 10
Global z.f = -30
Global Dim MeshData.PB_MeshVertex(0)

ExamineDesktops()
If OpenWindow(#mainwin, 0, 0, DesktopWidth(0), DesktopHeight(0), "isolate blue points from a cloud", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)


Define.f KeyX, KeyY
Declare UpdateMatrix()
Declare CreateMatrix()
Declare DrawMatrix()
Declare isolate()
Declare test()

If InitEngine3D()
  
  Add3DArchive(#PB_Compiler_Home + "Examples/3D/Data/Textures", #PB_3DArchive_FileSystem)
  Add3DArchive(#PB_Compiler_Home + "Examples/Sources\Data", #PB_3DArchive_FileSystem)
  Add3DArchive("/", #PB_3DArchive_FileSystem)
  
  InitSprite()
  InitKeyboard()
  OpenWindowedScreen(WindowID(#mainwin), 0, 0, DesktopWidth(0), DesktopHeight(0)-60, 0, 0, 0)
    
    CreateMaterial(0, LoadTexture(0, "White.jpg"))
    DisableMaterialLighting(0, #True)
    ;MaterialShadingMode(0, #PB_Material_Wireframe     )
    MaterialCullingMode(0, #PB_Material_NoCulling)
    CreateMatrix()
            
    CreateCamera(0, 0, 0, 100, 100)
    MoveCamera(0, 0, 0, 600, #PB_Absolute)
    CameraFOV(0, 70)
    CameraBackColor(0, $330000)
    CameraLookAt(0,0,0,0)
        
    CreateLight(0, RGB(255,255,255), 10, 60, -10)
    AmbientColor(RGB(90, 90, 90))
    
    MaterialBlendingMode(0, #PB_Material_AlphaBlend)   ; allow alphablending and vertex alpha
;MaterialBlendingMode(0, #PB_Material_Add )
;MaterialBlendingMode(0, #PB_Material_Color )
DisableMaterialLighting(0, 1)
       
    Repeat
      Event = WindowEvent()
                  
      If ExamineKeyboard()
                
        If KeyboardReleased(#PB_Key_Right)
          x - 0.4 :UpdateMatrix()
        
        ElseIf KeyboardReleased(#PB_Key_Q) 
          ;MessageRequester( "", Str(ArraySize(MeshData())))
          test()
                
        EndIf
        EndIf
      rot.f+0.6
      RotateEntity(0,0,rot,0)
      isolate() ; call blue points extraction procedure
      RenderWorld()
      FlipBuffers()
      
    Until KeyboardPushed(#PB_Key_Escape) Or Quit = 1
  EndIf
  
Else
  MessageRequester("Error", "The 3D Engine can't be initialized", 0)
EndIf

End


Procedure DrawMatrix()
    For i=0 To 100000 
  x = Random(200)-100:y = Random(200)-100:z = Random(200)-100
  If y< -80 And z< -80
    r=255:g=0:b=0
    ElseIf x < -80 And z< -80
      r=0:g=255:b=0
       ElseIf x< -80 And y< -80
         r=255:g=255:b=0
       Else
         r=255:g=119:b=119
       EndIf 
;(x - x0)^2 + (y - y0)^2 + (z - z0)^2 <= r^2  
;check if point inside a specific sphere:       
If (Pow(x,2) + Pow(y,2) + Pow(z,2)) <= 4900
  r=0:g=0:b=255
  
EndIf  

MeshVertexPosition(x, y, z)
MeshVertexColor(RGBA(r,g,b,100))  
;MeshVertexColor(RGB(r,g,b)) 

Next
    
EndProcedure  
Procedure CreateMatrix()
  
  CreateMesh(0, #PB_Mesh_PointList, #True)
  DrawMatrix()
  FinishMesh(#True)
  SetMeshMaterial(0, MaterialID(0))
    
  CreateEntity(0, MeshID(0), #PB_Material_None)
  
  ScaleEntity(0, 2, 2, 2)
  GetMeshData(0,0, MeshData(), #PB_Mesh_Vertex ,0, MeshVertexCount(0)-1)
  GetMeshData(0,0, MeshData(), #PB_Mesh_Color  ,0, MeshVertexCount(0)-1)
  
EndProcedure


Procedure UpdateMatrix()
  For i=0 To 50000
      MeshData(i)\x + x
      MeshData(i)\y + y
      MeshData(i)\z + z
      Next    
      SetMeshData(0,0, MeshData(), #PB_Mesh_Vertex  , 0, MeshVertexCount(0)-1)
    
    EndProcedure
    
 Procedure isolate()
   For i=0 To 100000
     ;16711680
     ;1677721855
     If MeshData(i)\Color = RGBA(255,0,0,100)
       MeshData(i)\x+1
       MeshData(i)\y+1
       
       
     EndIf
   Next
   SetMeshData(0,0, MeshData(), #PB_Mesh_Vertex, 0, MeshVertexCount(0)-1)
   
 EndProcedure
 
 Procedure test()

   MeshData(3)\Color = RGBA(255,0,0,100)
   Debug MeshData(3)\Color
 EndProcedure