ROAM and Height mapping

[A.H]

Can anyone please direct me to a pure Java3D ROAM and/or height mapping example?

Many thanks.

[Herkules]

IIRC, j3d.org has a ROAM implmentation. For a simpler heightmap, lookup my DRTS-project on sourceforge.

[A.H]

Ok Herkules, I decompiled SimpleHeighmap.class from your DRTS project.(Hope thats ok)

I understand everything until i got to this part

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private static Raster getHeightRaster(Image image, int i) {         int j = image.getWidth(null);         int k = image.getHeight(null);         int l = j / i;         int i1 = k / i;         BufferedImage bufferedimage = new BufferedImage(l, i1, 10);         bufferedimage.createGraphics().drawImage(image, 0, 0, l, i1, null);         return bufferedimage.getData(); }

I searched around the Java Docs and couldn't find the method for this

1	bufferedimage.createGraphics().drawImage(image, 0, 0, l, i1, null);

I know your drawing the image and then retrieving the Raster from the bufferedimage but can you explain the variables that

drawImage(image, 0, 0, l, i1, null);

takes?

Also what is the variable i, and why is j and k, the width and height being divided by it?(See code)

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int l = j / i; int i1 = k / i;

Another question, how would you go about creating a the terrain from the info you get from the Raster? Would you input the height info and stuff into a QuadArray?

Thanks.

Games published by our own members! Check 'em out!

[Herkules]

You don't have to decompile since you can download the sourcecode from CVS.

For now, I cannot explain in detail whats going on (and I personally haven't written that code).

Basically the heigthmap data is split into tiles, and for the tiles geometry is created. IIRC its a TriangleStrip.

In the game, view range and fog are adjusted to the size of the tiles, so that most of them are culled away.

[Mike Jacobs]

This article covers the basics of height maps and terrains: (JDJ Sept 2004) http://sys-con.com/story/?storyid=46231&DE=1.  It does not cover texture mapping or tesselation like ROAM.  There is another article that includes creation of terrain from external files including photos with texture mapping here: (JDJ June 2004) http://www.sys-con.com/story/?storyid=45087&DE=1.  Both include documented source.

Hope this helps.

Mike

[A.H]

Thanks Mike, Herkules, the info you gave me was really useful. I'll post any questions when i run into some problems.