I've looked at tnt, pumpkins, furnaces. All i can find with regards to the textures is this:

@SideOnly(Side.CLIENT)
@Override
public Icon getIcon(int side, int meta) {
	if(side == ForgeDirection.UP.ordinal())			
		return topIcon;
	else if(side == ForgeDirection.DOWN.ordinal())			
		return bottomIcon;
	else			
		return sideIcon;
}

 

and ofc, the icons are registered in: public void registerIcons(IconRegister par1IconRegister) ;

 

Now, what happens is, that in the player inventory etc, the block icons are correctly displayed with the these textures, but not in the world, in the world they are rendered with the black/purple checkerboard.

 

Am i forgetting something?

When is your block registered ?

in the

@EventHandler
        public void load(FMLInitializationEvent event) {

 

with these methods:

            GameRegistry.registerBlock(block, uniqueId);
            MinecraftForge.setBlockHarvestLevel(block, "pickaxe", 1);
            LanguageRegistry.addName(block, displayName);
            ModLoader.registerTileEntity(tileEntityClass, uniqueId);