How to implement a paged terrain ?

Author

Message

Juggernaut

14

Years of Service

User Offline

Joined: 12th Mar 2012

Location:

Posted: 22nd Jul 2012 00:13

Link

Hello,

How do I implement a paged terrain - means the whole terrain is split into seperete .x files and I want to load them when the camera
moves near one end / edge of the initial terrain.

Thanks,

Back to top

Profile PM

WLGfx

18

Years of Service

User Offline

Joined: 1st Nov 2007

Location: NW United Kingdom

Posted: 22nd Jul 2012 14:15

Link

It is possible but without multi-threading (which DBP does do) you would get a pause when you cross over boundaries and the new terrain sections are being loaded in.

+ Code Snippet

+---+---+---+
|   |   |   |
| 1 | 2 | 3 |
+---+---+---+
|   |   |   |
| 4 | M | 5 |
+---+---+---+
|   |   |   |
| 6 | 7 | 8 |
+---+---+---+

You would need to load up at least 9 segments and the camera would be in the centre segment. Once the camera crosses a boundary then your program will change the centre reference segment, discard the unused segments and re-load the other segments.

ie, if the camera moves into segment 2, segments 6, 7 and 8 will be discarded, the new centre will be 2 and segments 1, 2, and 3 will be loaded in.

Mental arithmetic? Me? (That's for computers) I can't subtract a fart from a plate of beans!
Warning! May contain Nuts!

Back to top

Profile PM Email Website

Juggernaut

14

Years of Service

User Offline

Joined: 12th Mar 2012

Location:

Posted: 22nd Jul 2012 22:37

Link

@WLGfx: Where do I hold the objects (chunks of terrain) in a multidimensional array ?

Back to top

Profile PM

Matty H

17

Years of Service

User Offline

Joined: 7th Oct 2008

Location: England

Posted: 22nd Jul 2012 23:51

Link

I have been thinking about this lately.

I think it's still possible without loading any extra meshes(or objects).

You would reuse the same meshes over and over but gradually change the height of the mesh vertices to represent the mesh you are travelling toward. You would work it so the mesh is exactly as it should be by the time you can see it.

You could fetch your height data using a networking plugin, you could also gradually alter images in the same way for your textures.

This technique would mean there are no limits to the size of your world(apart from server storage space

).

Back to top

Profile PM Email

Juggernaut

14

Years of Service

User Offline

Joined: 12th Mar 2012

Location:

Posted: 23rd Jul 2012 00:28

Link

Quote: "This technique would mean there are no limits to the size of your world(apart from server storage space)."

Yes that is what I want to achieve. But how to implement that in code is the real question.

Back to top

Profile PM

Rudolpho

20

Years of Service

User Offline

Joined: 28th Dec 2005

Location: Sweden

Posted: 23rd Jul 2012 00:41

Link

+ Code Snippet

#constant SEGMENTS_ACROSS 256
#constant SEGMENTS_DOWN   256

type coord
    x as float
    y as float
endtype

// ....

// After moving the camera
if cameraSegment <> oldCameraSegment
    camSeg    as coord
    oldCamSeg as coord
    camSeg.x     = cameraSegment mod SEGMENTS_ACROSS
    camSeg.y     = (cameraSegment - oldCamSeg.x) / SEGMENTS_ACROSS
    oldCamSeg.x  = oldCameraSegment mod SEGMENTS_ACROSS
    oldCamSeg.y  = (oldCameraSegment - oldCamSeg.x) / SEGMENTS_ACROSS
    
    for each camSeg (coord) in [(oldCamSeg.x - 1, oldCamSeg.y - 1) .. (oldCamSeg.x + 1, oldCamSeg.y + 1)] and not in [(camSeg.x - 1, camSeg.y - 1) .. (camSeg.x + 1, camSeg.y + 1)]
        delete / hide / move / whatever segment
    end for
    
    for each camSeg (coord) in [(camSeg.x - 1, camSeg.y - 1) .. (camSeg.x + 1, camSeg.y + 1)]
        if segment doesn't exist then create / show / update / whatever it
    end for
end if

Started out like a DBP snippet but turned into pseudo code as the actual code to achieve this would probably take half an hour to write. You probably want to use a two-dimensional array to store the segment data as well and as Matty H suggested you can re-use the same 9 segments by using the vertexdata functions to change them to correspond to geometry data for the segments that you have stored somewhere permanently (ie. you don't have to load a set of new meshes whenever you're changing the current segment).

"Why do programmers get Halloween and Christmas mixed up?"

+ Code Snippet

Because Oct(31) = Dec(25)

Back to top

Profile PM Email Website

Juggernaut

14

Years of Service

User Offline

Joined: 12th Mar 2012

Location:

Posted: 23rd Jul 2012 00:45

Link

Thanks Rudolpho .... I will look into your snippet.

Back to top

Profile PM

WLGfx

18

Years of Service

User Offline

Joined: 1st Nov 2007

Location: NW United Kingdom

Posted: 23rd Jul 2012 03:11

Link

The Bike game I wrote in DBP (and c++) used a single matrix terrain where the camera (and player) would cross boundaries onto another segment on the terrain, DBP would then scroll the terrain and the camera would be re-positioned. 3D Motor-Chase

Basically the movements would check against a range (ie 0-127) and then re-position the camera using DBP's MOD (modulus) command.

Mental arithmetic? Me? (That's for computers) I can't subtract a fart from a plate of beans!
Warning! May contain Nuts!

Back to top

Profile PM Email Website

Sorry your browser is not supported!

DarkBASIC Professional Discussion / How to implement a paged terrain ?