private HeightMap getHeightMapAt(Vector3f location) {
        // HEIGHTMAP image (for the terrain heightmap)
        int x = (int) location.x;
        int z = (int) location.z;
        
        AbstractHeightMap heightmap = null;
        //BufferedImage im = null;
        
        String name = null;
        try {
            name = namer.getName(x, z);
            logger.log(Level.FINE, "Loading heightmap from file: {0}", name);
            final Texture texture = assetManager.loadTexture(new TextureKey(name));
            heightmap = new ImageBasedHeightMap(texture.getImage());
            /*if (assetInfo != null){
                InputStream in = assetInfo.openStream();
                im = ImageIO.read(in);
            } else {
                im = new BufferedImage(patchSize, patchSize, imageType);
                logger.log(Level.WARNING, "File: {0} not found, loading zero heightmap instead", name);
            }*/
            // CREATE HEIGHTMAP
            /*if (imageType == BufferedImage.TYPE_USHORT_GRAY) {
                heightmap = new Grayscale16BitHeightMap(im);
            } else if (imageType == BufferedImage.TYPE_3BYTE_BGR) {
                heightmap = new ImageBasedHeightMap(im);
            } else if (customImageHeightmap != null && customImageHeightmap instanceof AbstractHeightMap) {
                // If it gets here, it means you have specified a different image type, and you must
                // then also supply a custom image heightmap class that can parse that image into
                // a heightmap.
                customImageHeightmap.setImage(im);
                heightmap = (AbstractHeightMap) customImageHeightmap;
            } else {
                // error, no supported image format and no custom image heightmap specified
                if (customImageHeightmap == null)
                    logger.log(Level.SEVERE, "Custom image type specified [{0}] but no customImageHeightmap declared! Use setCustomImageHeightmap()",imageType);
                if (!(customImageHeightmap instanceof AbstractHeightMap))
                    logger.severe("customImageHeightmap must be an AbstractHeightMap!");
                return null;
            }*/
            heightmap.setHeightScale(1);
            heightmap.load();
        //} catch (IOException e) {
        //    e.printStackTrace();
        } catch (AssetNotFoundException e) {
            logger.log(Level.WARNING, "Asset {0} not found, loading zero heightmap instead", name);
        }
        return heightmap;
    }
Affects the vertical scale of the terrain when loaded.
jme3-terrain/src/main/java/com/jme3/terrain/geomipmap/grid/ImageTileLoader.java