LibGDX textures rendering black - libgdx

Question

I know that there are many questions related to this, but none are relevant to my problem.
So, I have a TiledMap which has 2 layers for boxes in my game - one for the box graphics and one for the box objects. Now, I want to get the textures of all the boxes because I want to be able to draw them anywhere freely. So I wrote some code to find out which tiles a given rectangle (attained from the object layer of the boxes) is covering (this code works fine). Then, from the graphics layer (TileMapTileLayer), I am accessing the textures in those tiles and drawing them to a single texture using Pixmaps. Finally, I store this texture. However, when I render these textures, they are black. Heres the code -
TiledMapTileLayer boxLayer = (TiledMapTileLayer) (map.getLayers().get(2)); // this is the graphics layer
ArrayList<Vector2> cells;
Texture tex;
Pixmap pmap, pmapScld;
int numCols, numRows, cellNum;
int boxInd = 0;
FileTextureData texData;
StaticTiledMapTile tile;
for(RectangleMapObject boxBody : map.getLayers().get(3).getObjects().getByType(RectangleMapObject.class)) { //object layer
bounds = boxBody.getRectangle();
cells = getOccupiedCells(bounds);
numCols = (int) cells.get(0).x; //I have stored the width and height of the texture
numRows = (int) cells.get(0).y; //in tiles in the first Vector2 of the Array
tex = new Texture(numCols * tileWidthOrg, numRows * tileHeightOrg, Format.RGBA8888);
cellNum = 1;
System.out.println(cells);
for(int i = 0 ; i < numCols ; i++) {
for(int j = 0 ; j < numRows ; j++) {
tile = (StaticTiledMapTile) (boxLayer.getCell((int) cells.get(cellNum).x, (int) cells.get(cellNum).y).getTile());
texData = (FileTextureData) tile.getTextureRegion().getTexture().getTextureData();
texData.prepare();
pmap = texData.consumePixmap();
//pmapScld = new Pixmap(tileWidthScld, tileHeightScld, pmap.getFormat());
//pmapScld.drawPixmap(pmap, 0, pmap.getHeight(), pmap.getWidth(), pmap.getHeight(),
//0, pmapScld.getHeight(), pmapScld.getWidth(), pmapScld.getHeight());
tex.draw(pmap, i * tileWidthOrg, j * tileHeightOrg);
pmap.dispose();
texData.disposePixmap();
//pmapScld.dispose();
cellNum++;
}
}
contactListener.addBox(new GBox(world, tex, bounds, boxInd));
tex.dispose();
boxInd++;
}
The code for rendering these boxes -
for(GBox box : contactListener.boxes) {
box.render(sb);
}
public void render(SpriteBatch sb) {
sb.draw(tex, body.getPosition().x - width / 2, body.getPosition().y - height / 2, width, height);
//System.out.println("rendering box " + index + " at position " + body.getPosition());
}