How to apply CLOD to terrain

General Discussion
1

How do we apply LOD algorithms to terrain pages ? im asking this because the TerrainPage class isnt derived

from the TriMesh class .



thanks

2

Well, in the end TerrainPage consist other terrainpages and at the leafs it is TerrainBlocks again (which are TriMeshs).

All you would have to do is to traverse the TerrainPage-Tree and replace the TerrainBlocks by ClodObjects of the TerrainBlocks. Hi think I tried this once but afaik it looked quite ugly, especially at the edges of the terrainblocks. Actually I'm not sure if I really did it riight, so give it a try. (And tell about the result)



Keep on rocking

3

thanks

Ill give it a try .

4

rocha here is a method that returns clod of a terrain page but it has two problems

1- in the "not complete" section i didnt know exactly how to create a clod mesh from the terrain block and

2- the resulting terrain page doesnt act exactly  as a terrain page for example it doesnt have height information and

must be set






    TerrainPage getTerrainPageCLOD(TerrainPage tp) {

        TerrainPage clodPage = new TerrainPage();
        clodPage.setModelBound(tp.getWorldBound());
        clodPage.setSize(tp.getSize());
        clodPage.setSize(tp.getSize());
        clodPage.setStepScale(tp.getLocalScale());
        for (int i = 0; i < tp.getSize(); i++) {
            for (int j = 0; j < tp.getSize(); j++) {
                clodPage.setHeightMapValue(i, j, tp.getHeight(i, j));
            }
        }


        for (int i = 0; i < tp.getQuantity(); i++) {
            int size123 = tp.getSize();
            int quarterSize = size123 >> 2;

            if (tp.getChild(i).getClass() == new TerrainPage().getClass()) {
                TerrainPage temp = getTerrainPageCLOD((TerrainPage) tp.getChild(i));

                switch (i) {
                    case 0:
                        Vector2f offset = new Vector2f();
                        offset.x = tp.getLocalTranslation().getX();
                        offset.y = tp.getLocalTranslation().getY();


                        Vector3f origin1 = new Vector3f(-quarterSize * tp.getStepScale().x, 0,
                                -quarterSize * tp.getStepScale().z);


                        temp.setLocalTranslation(origin1);


                        break;
                    case 1:

                        Vector3f origin2 = new Vector3f(-quarterSize * tp.getStepScale().x, 0,
                                quarterSize * tp.getStepScale().z);

                        temp.setLocalTranslation(origin2);
                        break;
                    case 2:

                        Vector3f origin3 = new Vector3f(quarterSize * tp.getStepScale().x, 0,
                                -quarterSize * tp.getStepScale().z);

                        temp.setLocalTranslation(origin3);
                        break;
                    case 3:
                        Vector3f origin4 = new Vector3f(quarterSize * tp.getStepScale().x, 0,
                                quarterSize * tp.getStepScale().z);

                        temp.setLocalTranslation(origin4);
                        break;
                }

                // ==========================================================================
                clodPage.attachChild(temp);

            } else if (tp.getChild(0).getClass() == new TerrainBlock().getClass()) {  
                
                //===================== not complete
                AreaClodMesh acm = new AreaClodMesh("acm" + Math.random(), (TriMesh) (tp.getChild(i)), null);
                acm.setTrisPerPixel(0.02f);
                acm.setModelBound(new BoundingBox());
                acm.setLocalTranslation((tp.getChild(i)).getLocalTranslation());
                acm.updateModelBound();                            
                //=====================
                clodPage.attachChild(acm);
            }
        }
        return clodPage;

    }




a better aproach would be take the TerrainPage class source and make clod meshes directly there .