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The Quake II's MD2 File In PV3D

6. August 2008 by Ferris.Yeung 1 Comments

Introduction

“Yeah a new MD2 tutorial yet...” Yes but mine will show you how to render them by a different way ;-) But what the heck is an MD2 anyway? the MD2 file format is a 3D model file format used in Id Software's Quake II engine! And here I'll show you how to load and display it to the screen using OpenGL!

You probably think “Damn, this guy stuck in the 1997 old' days” but there are good reasons to use it. First because the MD2 file format is a good 3D model file format for learning because of it simplicity (if you're a beginner, you may not understand this, but look at other model file formats and you'll see ;-)) and then, because this format is absolutely free!!! (but not models, be careful!).

The MD2 File Format

Like most file formats, the MD2 file format is composed of two things: a file header and the data. The header contains some very important variables used when loading the file like the size of the file data to load, a magic number or the version of the format, so its size must be always the same. That's why generally the header is a structure. In opposition, the size of the data can vary from one file to another and contains multiple structures for vertices, triangles, texture coordinates, etc...

Here is the MD2 header structure definition

// MD2 Header

typedef struct

{

    int     ident;              // magic number. must be equal to "IDP2"

    int     version;            // md2 version. must be equal to 8

  

    int     skinwidth;          // width of the texture

    int     skinheight;         // height of the texture

    int     framesize;          // size of one frame in bytes

  

    int     num_skins;          // number of textures

    int     num_xyz;            // number of vertices

    int     num_st;             // number of texture coordinates

    int     num_tris;           // number of triangles

    int     num_glcmds;         // number of opengl commands

    int     num_frames;         // total number of frames

  

    int     ofs_skins;          // offset to skin names (64 bytes each)

    int     ofs_st;             // offset to s-t texture coordinates

    int     ofs_tris;           // offset to triangles

    int     ofs_frames;         // offset to frame data

    int     ofs_glcmds;         // offset to opengl commands

    int     ofs_end;            // offset to end of file

  

} md2_t;

In newly PV3D version, mostly code class had been modified. so…

package

{

    import flash.display.*;    

    import flash.events.*;

    

    import org.papervision3d.core.*;

    import org.papervision3d.core.proto.*;

    import org.papervision3d.scenes.*;

    import org.papervision3d.cameras.*;

    import org.papervision3d.objects.*;

    import org.papervision3d.materials.*;

    import org.papervision3d.render.*;

    import org.papervision3d.view.*;

    import org.papervision3d.materials.shaders.*;

    import org.papervision3d.core.render.data.*;

    import org.papervision3d.objects.parsers.*;

    import org.ascollada.core.DaeController;    

    

    public class MD2Loading    extends Sprite

    {

        var camera:Camera3D;

        var scene:Scene3D;

        var renderer:BasicRenderEngine;

        var viewport:Viewport3D;

        

        var md2:MD2;

        

        var material:BitmapFileMaterial;

        

        public function MD2Loading()

        {

            init3D();

        }

        

        public function init3D()

        {

            scene = new Scene3D();

            camera = new Camera3D();

            viewport = new Viewport3D( stage.stageWidth, stage.stageHeight, false, false, true, true );

            renderer = new BasicRenderEngine();

            camera.zoom = 40;

            camera.z = -100;

            scene.addChild( camera );

            addChild( viewport );

            

            material = new BitmapFileMaterial( "model/images/dragon.jpg" );

            

            //private var myMD2:Class;

            var md2:MD2 = new MD2();

            md2.load( "model/tris.md2", material );

            

            md2.rotationX = -90;

            md2.rotationY = 45;

            

            scene.addChild( md2 );

            addEventListener(Event.ENTER_FRAME,loop3d); 

        }

        

        private function loop3d(e:Event):void

        {

            renderer.renderScene(scene, camera, viewport);

        }

  

    }

}