Client/Server Networking in JPCT-AE

[arianaa30]

Hi everybody,
It seems there is no specific networking API predefined in JPCT-AE. I want to transfer the objects from a server to a client, then try to render them and run the game. The simple method is using Android's API, creating a connection and simply transfer the items. Does it work? Is there any alternatives for that? Thanks

[EgonOlsen]

It highly depends on what exactly you want to do. If you just want to load models from a server, i would simply load them via http.

...and why not include the models in the APK?

[Darkflame]

I have successfully got 3ds (created by 3dsmax) objects loaded from a sever, with textures, provided the textures are in a known location on the server so yes, it does work. Or, at least, can work

The following is code taken straight from my app. Its VERY messy, and uses a few things specific too my app.
However, it should give you some keywords too look for.

Code Select Expand

//its a 3ds file , so a mesh
object3dtype = ARBlipObject.ObjectType.MESH_OBJECT;

HashSet<String> Namesbefore = TextureManager.getInstance()
.getNames();
int SizeBefore = Namesbefore.size();

// load 3d model
URL downloadfrom = new URL(newblip.ObjectData);
URLConnection conn = downloadfrom.openConnection();
conn.connect();
BufferedInputStream bis = new BufferedInputStream(conn
.getInputStream());
Log.i("3ds", "got stream");
Object3D[] newobjects = Loader.load3DS(bis, 1);

for (int x = 0; x < newobjects.length; x++) {
newobjects[x].rotateX((float) Math.PI / 2);
newobjects[x].rotateZ((float) Math.PI);
newobjects[x].rotateY(-((float) Math.PI / 2));

newobjects[x].rotateMesh();
newobjects[x].setRotationMatrix(new Matrix());
}

Log.i("3ds", "now merging...");
newmarker = Object3D.mergeAll(newobjects);

// This scale is wrong...no idea what the correct scale to use
// is :(
// newmarker.scale(2f);

// clear memory first
System.gc(); // no idea if this is a good place, but I was
// getting some out of memory errors without it

// ok, if occlusion is set, then we simply dont specify a
// texture
if (newblip.isOcculisionMask) {

newmarker.setTexture("occlusion");

return newmarker;
}

HashSet<String> newNames = TextureManager.getInstance()
.getNames();

newNames.removeAll(Namesbefore);

// now get the texture names
Iterator<String> it = newNames.iterator();

// get path
String URLPath = newblip.ObjectData.substring(0,
newblip.ObjectData.lastIndexOf('/') + 1);

try {
ARWaveView.fetchAndSwapTexturesFromURL(it, URLPath);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Log.i("3ds", "created 3ds");


Code Select Expand

static void fetchAndSwapTexturesFromURL(Iterator<String> it, String URLPath)
throws MalformedURLException, IOException {
while (it.hasNext()) {

String textureNameToLoad = (String) it.next();
Log.i("3ds", "Loading Texture:-" + textureNameToLoad);

// get the url
// NOTE; filename must be lower case
// In future we might want to check for uppercase too.
// Unfortunately, 3dsmax stores all its filenames uppercase
// internally, so we cant have mixed cases
// in filenames, as they wont be recognised.
String TextureURL = URLPath + textureNameToLoad.toLowerCase();

Log.i("3d", "getting texture at " + TextureURL);

// make the texture
URL texturedownloadfrom = new URL(TextureURL);
URLConnection textureconnection = texturedownloadfrom
.openConnection();

textureconnection.connect();
BufferedInputStream texturebis = new BufferedInputStream(
textureconnection.getInputStream());

Bitmap maxtexture1 = BitmapFactory.decodeStream(texturebis);
TextureManager tm = TextureManager.getInstance();
Texture newmaxtexture = new Texture(maxtexture1);

// swap it in
// Note; This automatically assigns the correct textures onto the
// model, because when the model was loaded, it was assigned the file names in the
// 3ds file for its texture names.
// neat eh?
tm.replaceTexture(textureNameToLoad, newmaxtexture);

}
}


Now, the tricker thing is sending a mesh from the client app to the server....

[arianaa30]

It highly depends on what exactly you want to do. If you just want to load models from a server, i would simply load them via http.

...and why not include the models in the APK?

Well Egon, I need to test the streaming using a client/server connection. So can not include them in the code...

[arianaa30]

I have successfully got 3ds (created by 3dsmax) objects loaded from a sever, with textures, provided the textures are in a known location on the server so yes, it does work. Or, at least, can work

The following is code taken straight from my app. Its VERY messy, and uses a few things specific too my app.
However, it should give you some keywords too look for.

Now, the tricker thing is sending a mesh from the client app to the server....

ummm, seems it would work...let me try it. Thanks buddy

[arianaa30]

I tested the approach, and it works, as expected. But a problem is that when the app is trying to receive the texture, everything freezes during transmission. Do you have any idea for that?
To Egon: I'm using jpct-AE Demo code, and in order to test, when number of passed frames equals 100 in the onDrawFrame(), I try receiving a texture to replace an older one.

[Thomas.]

You have to use another thread for downloading new textures to avoid freeze during transmission.