I used MCEdit and exported a building as .NBT and I was able to get BlockPos's as well the block using Block#getBlockFromName() but I have no idea how to get the BlockState properties. I know where they are stored but I don't know how to convert them to Block State. See the picture. For example at the first index in the Properties Compount Tag it has a property snowy: false. What I would use is 

Blocks.GRASS.getDefaultState().withProperty(BlockGrass.SNOWY, false)

Searching the minecraft's source code I found some classes like IBlockStatePalette that I suspect they can transform this but I do not know how to use it

Edited April 20, 20178 yr by GeorgeTsak

Unsure if this class exists in 1.9.4, but NBTUtil#func_190008_d takes an NBTTagCompound (which has an IBlockState serialized within it) and returns the proper IBlockState.
You can see how vanilla MC makes use of this in Template#read.

7 hours ago, Matryoshika said:

Unsure if this class exists in 1.9.4, but NBTUtil#func_190008_d takes an NBTTagCompound (which has an IBlockState serialized within it) and returns the proper IBlockState.
You can see how vanilla MC makes use of this in Template#read.

 

OK since func_190008_d does not exist,I used the Template#read method like this:

public class NBTBuilding {

    NBTTagCompound nbtTagCompound;

    public NBTBuilding(String filename){
       try {

           InputStream is = Schematic.class.getResourceAsStream("/assets/modname/schematics/" + filename + ".nbt");
           this.nbtTagCompound = CompressedStreamTools.readCompressed(is);
           is.close();
       }
       catch (Exception e){
           FMLLog.warning("Error occurred while reading " + filename + ".nbt");
           FMLLog.warning(String.valueOf(e));
       }
    }

    public void createBuilding(World world, int x, int y, int z){
        //System.out.println("Requested to create a building at " + x + ", " + y + ", " + z);

        Template template = ((WorldServer)(world)).getStructureTemplateManager().getTemplate(world.getMinecraftServer(), new ResourceLocation(ModName.MODID, "name"));
        template.read(nbtTagCompound);
        template.addBlocksToWorldChunk(world, new BlockPos(x, y, z), new PlacementSettings());

    }

}

Well the structure generates in the correct shape however the blocks are messed up... Not a single block is correct. Eg instead of Stone it uses Lava. Checking here http://minecraft.gamepedia.com/Structure_block_file_format I see that my NBT file has the correct format. Any clue?

Edited April 20, 20178 yr by GeorgeTsak
Provide more info

Ok finally I got it. Aparrently the read method of Template does not work with the new Structure NBT of the 1.10+ So what I did was create a custom class copying the read code from 1.10. Now it works perfectly even if code is messed up a bit.