Wolf3D

[ScottB]

I am having trouble calculating basic raycasting program.  I was wondering if someone could help me.
Just the intersects i tried but mine is too buggy. I will work on one though if someone sends me at least the raycasting lines done fast. I get parts of this program but not others good enough to my likeing so i'm asking for help at least get one done thats not glichy like some of my work here is. I Think this is a hard study and work load for one person to wrap head around. so a little help is all's im asking. thanks and thanks again by for now Scott B.

[kevin]

  The ray intersections can be handle through collision worlds and then you just world out what tile it hit and what fragment to draw. 


 

PlayBASIC Code: [Select]

; PROJECT : Ray Intersect World within simple map
; AUTHOR  : 
; CREATED : 17/12/2024
; EDITED  : 17/12/2024
; ---------------------------------------------------------------------

    openscreen 1280,900,32,1

    Map_Height = 16
    Map_Width    = 16

    dim Map(Map_Width,Map_Height)
    
    for ylp=0 to Map_Height-1
        row$=readdata$()
        for xlp=0 to Map_Width-1
            ThisBLOCK=mid(row$,1+xlp)-asc("0")
            Map(xlp,ylp) = ThisBLOCK
        next        
    next



; Get the Screen size and use it as the world size
  WorldWidth=GetScreenWidth()
  WorldHeight=GetScreenHeight()
  
; create a Camera
  MyCamera=NewCamera()
  
; Create world
  MyWorld=NewWorld()
  CaptureToWorld MyWorld
  
; draw a series of boarder line for this world
  Line 0,0,worldwidth,0
  Line worldwidth,0,worldwidth,worldheight
  Line worldwidth,worldheight,0,worldheight
  Line 0,worldheight,0,0
  
  
  
  BlockSizeX#= WorldWidth /float(Map_Width)
  BlockSizeY#= WorldHeight/float(Map_Height)
  
  //  Draw the map edges to collision for ray intersection
      For ylp=0 To Map_Height-1
          For xlp=0 To Map_Width-1
                ThisBLOCK = map(xlp,ylp)
                if ThisBLOCK=0 then continue
                // If this is wall block; then check edges

                x1# = xlp        *BlockSizeX#
                x2# = (xlp+1)    *BlockSizeX#
                y1# = ylp        *BlockSizeY#
                y2# = (ylp+1)    *BlockSizeY#

                // edges f this block
                if (ylp-1)>=0
                  if map(xlp,ylp-1)=0
                        Line x2#,y1#,x1#,y1#  // Top
                    endif
                endif

                if (ylp+1)<=Map_Height
                  if map(xlp,ylp+1)=0
                        Line x1#,y2#,x2#,y2#  // bottom
                    endif
                endif    
                
                if (xlp-1)>=0
                  if map(xlp-1,ylp)=0
                    Line x1#,y1#,x1#,y2#        // Left 
                    endif
                endif    

                if (xlp+1)<=Map_Width
                  if map(xlp+1,ylp)=0
                        Line x2#,y2#,x2#,y1#        // Right 
                    endif
                endif    
            next
        next      
  
  
  
; Partition The world up into 32 by 32 cells
  PartitionWorld MyWorld,32
  
; Tell PlayBASIC to return to Immediate drawing mode
  DrawGFXImmediate
  
  
; statrt of DO/Loop
  Do

  ; capture to scene and grab the world info
    CaptureToScene
    ClsScene
    CaptureDepth 100
    CameraGrabWorld MyCamera,MyWorld
    
    
  ; Get the mouse position
    mx#=MouseX()
    my#=MouseY()
    
  ; Cast 150 rays out from the mouses position
    rays=150
    For Ray=1 To Rays
        angle#=(360.0/Rays)*Ray
        x2#=CosNewValue(mx#,angle#,400)
        y2#=SinNewValue(my#,angle#,400)
        If RayIntersectWorld(MyWorld,mx#,my#,x2#,y2#)=true
          x2#=GetIntersectX#(0)
          y2#=GetIntersectY#(0)
          CircleC x2#,y2#,3,1,RGB(255,0,0)
        EndIf
        Line mx#,my#,x2#,y2#
    Next
    
  ; draw the camera
    DrawCamera MyCamera
    
  ; show the fps rate and continue this loop
    Text 0,0,FPS()
    Sync
  Loop spacekey()
  
  end
  



    data "11111111111111111111"
    data "10000000000000000001"
    data "10001111111110000001"
    data "10001000000010000001"
    data "10001111100010000001"
    data "10000000000000011001"
    data "10000000000000011001"
    data "10000001000000000001"

    data "10000000000000000001"
    data "10000000000000000001"
    data "100100110011001100001"
    data "10011111111100110001"


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  Related Links:

    - See Ray Intersect World command in PlayBASIC HELP

    - See Yet Another Wolfenstein 3D Demo (Texture Mapped Floors & Ceiling)

[ScottB]

Awesome! But...
How would I get texture mapping done.

Is is something like X1_Ray / X_Cell_Size Mod block size???

[kevin]

  The texture strip commands. 

  TEXTURESTRIPV]TEXTURESTRIPV
  TEXTURESTRIPH]TEXTURESTRIPH

[stevmjon]

i was playing around with this world (which i have never used before as i use maps instead), and i was trying to find the current block the ray was intersecting with but it seems to be slightly off in different parts of the screen. i picked ray 112 for this example (see below).

the red box highlights the block the ray intersects with, but if you use the intersection location it can be slightly out when calculating and you see the block next to it instead. should i use a different calculation than the one below?

x2# = GetIntersectX#(0)
x = (GetCameraX(MyWorld) + x2#) / BlockSizeX#

or
x = (GetCameraX(MyWorld) + Int(x2#)) / BlockSizeX#

PlayBASIC Code: [Select]

; PROJECT : Ray Intersect World within simple map
; AUTHOR : Kevin Picone
; CREATED : 17/12/2024
; EDITED : 17/12/2024
; ---------------------------------------------------------------------

OpenScreen 1280,900,32,1

Map_Height = 16
Map_Width  = 20

Dim Map(Map_Width,Map_Height)

For ylp=0 To Map_Height-1
  row$=ReadData$()
  For xlp=0 To Map_Width-1
      ThisBLOCK=Mid(row$,1+xlp)-Asc("0")
      Map(xlp,ylp) = ThisBLOCK
  Next
Next



;Get the Screen size and use it as the world size
WorldWidth=GetScreenWidth()
WorldHeight=GetScreenHeight()

;create a Camera
MyCamera=NewCamera()

;Create world
MyWorld=NewWorld()
CaptureToWorld MyWorld

;draw a series of boarder line for this world
Line 0,0,worldwidth,0
Line worldwidth,0,worldwidth,worldheight
Line worldwidth,worldheight,0,worldheight
Line 0,worldheight,0,0



BlockSizeX#= WorldWidth /Float(Map_Width)
BlockSizeY#= WorldHeight/Float(Map_Height)

//Draw the map edges to collision for ray intersection
For ylp=0 To Map_Height-1
  For xlp=0 To Map_Width-1
      ThisBLOCK = map(xlp,ylp)
      If    ThisBLOCK=0 Then Continue
      
      //If this is wall block; then check edges
      
      x1# = xlp      *BlockSizeX#
      x2# = (xlp+1)  *BlockSizeX#
      y1# = ylp      *BlockSizeY#
      y2# = (ylp+1)  *BlockSizeY#
      
      //edges f this block
      If (ylp-1)>=0
        If map(xlp,ylp-1)=0
            Line x2#,y1#,x1#,y1#  // Top
        EndIf
      EndIf
      
      If (ylp+1)<=Map_Height
          If map(xlp,ylp+1)=0
              Line x1#,y2#,x2#,y2#  // bottom
          EndIf
      EndIf
      
      If (xlp-1)>=0
        If map(xlp-1,ylp)=0
            Line x1#,y1#,x1#,y2#  // Left
        EndIf
      EndIf
      
      If (xlp+1)<=Map_Width
        If map(xlp+1,ylp)=0
            Line x2#,y2#,x2#,y1#  // Right
        EndIf
      EndIf
  Next
Next



;Partition The world up into 32 by 32 cells
PartitionWorld MyWorld,32

;Tell PlayBASIC to return to Immediate drawing mode
DrawGFXImmediate

;===============================================================================

;start of DO/Loop
Do
  
  ; capture to scene and grab the world info
  CaptureToScene
  ClsScene
  CaptureDepth 100
  CameraGrabWorld MyCamera,MyWorld
  
  ; Get the mouse position
  mx#=MouseX()
  my#=MouseY()
  
  ; Cast 150 rays out from the mouses position
  rays=150
  For Ray=1 To Rays
      angle#=(360.0/Rays)*Ray
      x2#=CosNewValue(mx#,angle#,400)
      y2#=SinNewValue(my#,angle#,400)
      If RayIntersectWorld(MyWorld,mx#,my#,x2#,y2#)=true
        x2#=GetIntersectX#(0)
        y2#=GetIntersectY#(0)
        CircleC x2#,y2#,3,1,RGB(255,0,0)
        
        If Ray = 112  ;  pick a ray to focus on
            ; get current block
            x = (GetCameraX(MyWorld) + x2#) / BlockSizeX#
            y = (GetCameraY(MyWorld) + y2#) / BlockSizeY#
            
            ; highlight block ray collides with
            BoxC x*BlockSizeX#+1,y*BlockSizeY#+1,x*BlockSizeX# + BlockSizex#-1,y*BlockSizeY# + BlockSizeY#-1,0,rgb(255,0,0)  ;  highlight block
            BoxC x*BlockSizeX#+2,y*BlockSizeY#+2,x*BlockSizeX# + BlockSizex#-2,y*BlockSizeY# + BlockSizeY#-2,0,rgb(255,0,0)
              
            CircleC x2#,y2#,6,1,RGB(0,255,0)  ;  highlight ray tip (collision=on)
         EndIF
            
      EndIf
      LineC mx#,my#,x2#,y2#,RGB(150,150,0)
      
      If Ray = 112 then CircleC x2#,y2#,3,1,RGB(0,255,0)  ;  highlight ray tip (collision=off)
  Next
  
  ; draw the camera
  DrawCamera MyCamera
  
  ; show the fps rate and continue this loop
  Text 0,0,FPS()
  Sync
  
Loop SpaceKey()

;===============================================================================


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[ScottB]

This is awesome! Advanced Raycasting!
My question is this, How do I render the walls. I need a place like an image to render to.
My distances and fisheye removal work great but I need a spot to render the output for final viewing.
I don't want the camera 2D but I want to use it render 3d output but I can't just render it to the screen with the 2d camera data.
Any suggestions are welcome thanks
Scottie B

[kevin]

  The heights are computed the same way as your older Wolf3D demo 

  We've just shifted the ray casting from something the user is doing, to something that's built in


  Here's a version of the original code with the scene rendered as series of vertical line fragments much the same as how Wolf 3D would have worked.    Source Code cut'n'paste the perspective correction from the either you're original demo or one of Steve's edits.. dunno 

 

PlayBASIC Code: [Select]

    openscreen 1280,900,32,1
    setfps 60

    Map_Height = 16
    Map_Width    = 16

    dim Map(Map_Width,Map_Height)
    
    for ylp=0 to Map_Height-1
        row$=readdata$()
        for xlp=0 to Map_Width-1
            ThisBLOCK=mid(row$,1+xlp)-asc("0")
            Map(xlp,ylp) = ThisBLOCK
        next        
    next



; Get the Screen size and use it as the world size
  WorldWidth=GetScreenWidth()
  WorldHeight=GetScreenHeight()
  
; create a Camera
  MyCamera=NewCamera()
  
; Create world
  MyWorld=NewWorld()
  CaptureToWorld MyWorld
  
; draw a series of boarder line for this world
  Line 0,0,worldwidth,0
  Line worldwidth,0,worldwidth,worldheight
  Line worldwidth,worldheight,0,worldheight
  Line 0,worldheight,0,0
  
  
  
  BlockSizeX#= WorldWidth /float(Map_Width)
  BlockSizeY#= WorldHeight/float(Map_Height)
  
  ink $ff0000
  
  //  Draw the map edges to collision for ray intersection
      For ylp=0 To Map_Height-1
          For xlp=0 To Map_Width-1
                ThisBLOCK = map(xlp,ylp)
                if ThisBLOCK=0 then continue
                // If this is wall block; then check edges

                x1# = xlp        *BlockSizeX#
                x2# = (xlp+1)    *BlockSizeX#
                y1# = ylp        *BlockSizeY#
                y2# = (ylp+1)    *BlockSizeY#

                // edges f this block
                if (ylp-1)>=0
                  if map(xlp,ylp-1)=0
                        Line x2#,y1#,x1#,y1#  // Top
                    endif
                endif

                if (ylp+1)<=Map_Height
                  if map(xlp,ylp+1)=0
                        Line x1#,y2#,x2#,y2#  // bottom
                    endif
                endif    
                
                if (xlp-1)>=0
                  if map(xlp-1,ylp)=0
                    Line x1#,y1#,x1#,y2#        // Left 
                    endif
                endif    

                if (xlp+1)<=Map_Width
                  if map(xlp+1,ylp)=0
                        Line x2#,y2#,x2#,y1#        // Right 
                    endif
                endif    
            next
        next      
  
  ink -1
  
  
; Partition The world up into 32 by 32 cells
  PartitionWorld MyWorld,32
  
; Tell PlayBASIC to return to Immediate drawing mode
  DrawGFXImmediate



    Number_Of_Rays=getscreenwidth()  

    Field_Of_View = 60

    Angle_Inc# = Float(Field_Of_View) / Number_Of_Rays 

    Dim Distortion_Removal#(Number_Of_Rays)
    For Rays = 0 To Number_Of_Rays - 1
        Ray_Angle# = Angle_Inc# * Rays
        Distortion_Removal#(Rays) = Cos(-(Field_Of_View / 2) + Ray_Angle#)
    Next Rays    


//    X1_Player=mousex()
//Y1_Player=mousey()

    Player_X# = getscreenwidth()/2
    Player_Y# = 500
    Player_Angle# = 300


  
; statrt of DO/Loop
  Do

  ; capture to scene and grab the world info
    CaptureToScene
    ClsScene
    CaptureDepth 100
    CameraGrabWorld MyCamera,MyWorld


    if mousebutton()=1
      ; Get the mouse position
        player_x#=MouseX()
              player_y#=MouseY()
    endif    
    
    
    Ray_Angle# = 0  
    Magnitude=1000
    
    for xlp=0 to getscreenwidth()-1

            Distance_To_Wall# = Dist_1#
            X2# = Player_X# + Cos(Player_Angle# - (Field_Of_View / 2) + Ray_Angle#) * Magnitude
            Y2# = Player_Y# + Sin(Player_Angle# - (Field_Of_View / 2) + Ray_Angle#) * Magnitude

        If RayIntersectWorld(MyWorld,Player_X#,Player_Y#,x2#,y2#)=true
          x2#=GetIntersectX#(0)
          y2#=GetIntersectY#(0)
        EndIf

            Distance_To_Wall#=getdistance2d(Player_X#,Player_Y#,x2#,y2#)

            Distortion_Correction# = Distance_To_Wall# * Distortion_Removal#(xlp)

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[ScottB]

Looks great! but how do I hide the map during wall rending?
Texture mapping is usually a Mod operation to get offsets to texturestripV.
Any ideas how to do this quickly in the advanced raycaster?

When dealing with Wolfenstein 3D I had two rays that is why I only get dome texturemapping right as you see below.

So now how do I do it. Texturemap blocksize wall repeatedly? I also need to define textures a right angles to get light dark and lite on one side or the other.

Mod takes care of repeated blocksize textures as you get a hint from the file below.

So my two questions kevin is how not to show map? and how to texturemap advanced raycaster?

Thanks ScottieBro

[kevin]

Looks great! but how do I hide the map during wall rending?

  See-> CameraGrabWorld


 To compute the texture offset requires picking an axis (X or Z) of the intersection. 

 All we know is the ray hit some edge of a tile out there in space.   From that location we'd need work out what side of the tile the ray hit.  So did the ray impact along side that X aligned  (left/right) or Z (top /bottom) aligned ?   Choose a side and then get the modulus of the position. 

[ScottB]

Can you show me with an example of this in action. OUr program is coming around good. I hate to let it stop here.
What do you mean by cameragrabworld for the map for one. and secondly how do I seperate horizontal and vertical mods for texturemapping. Kevin, I need your help here as this is an advance raycaster more like doom.
Thanks ScottieBro

[kevin]

 

What do you mean by cameragrabworld for the map for one.

  It renders the 'world' to the scene.  The MAP is made up of  line fragments stored in a world. The fragments are what the Ray casting is finding impacts against. 

and secondly how do I seperate horizontal and vertical mods for texturemapping.

   attached...       

I need your help here as this is an advance raycaster more like doom.

   I don't have time.. 

   

[ScottB]

Texturemapping is now looking really good.
Could you still teach my how to hide the map. See it with tab or something.

I'd hat to see this project die out.  Can you show me how to hide map or tab to see it like I said.
I'm not good at world scene functions. and I quess doors would come next which are polygons in original wolf3d.

This program rocks!!! I hope it moves on from here.
but an example on how to hide/show map would be good for now.
Love what you did with textures.

I have tried to program this program alot so I hope this time it won't get abandoned.

but examples are great! keep up the good work.
Scottie B.

[stevmjon]

if you press key 'M' this hides / shows map.

also if change Map_Width = 20 , this makes the walls square on map, and fits whole map on the screen.

i remember doors on the version 'Wolf3D_edit1'. this was just allowing for an offset for the door height going up and applying this to the TextureStripV command. did you want to make this a polygon instead?

   stevmjon

[kevin]

  There's a number of things missing tidbits for you work on beyond doors.

  The main show stopper is transparent objects (sprites).

   Which would require the scene be rendered in passes.  So compute depth map (solid walls pass) and cache results.     This not only gives you the depth/wall strip but also the occlusion for each strip in the scene.   So a sprite is drawn strip by strip clipped against the depth map.  Only Strips that are in front of the current Z get drawn. 

  Sprites (transparent) objects also need to be sorted for rendering, ensuring far far sprites appear behind near sprites.   

 

[kevin]

Ray Casting - Wolf 3D demo #2  - Slow Mo Render

    This is the version of the code used in the video (attached bellow) which takes the viewing through basics of how the ray casting works and how we can determine what column from the wall texture we need to render at each position across the screen. 


    Controls:

    Arrow Keys = Move Camera
    M          = Toggle Map
    Enter      = Render Scene In Slow Motion with overlaps

    Mouse Left button = Position Camera