Lit column block example

column_block.java

final SimpleModelState defaultState = XmPrimitives.COLUMN_SQUARE.newState()
        .paint(SquareColumnPrimitive.SURFACE_MAIN, XmPaint.finder()
                .textureDepth(2)
                .texture(0, XmTextures.BIGTEX_SANDSTONE)
                .textureColor(0, 0xFF99BBAA)
                .texture(1, XmTextures.BORDER_GRITTY_SINGLE_LINE)
                .blendMode(1, BlockRenderLayer.TRANSLUCENT)
                .textureColor(1, 0xFF709080)
                .find())
        .paint(SquareColumnPrimitive.SURFACE_CUT, XmPaint.finder()
                .texture(0, XmTextures.BIGTEX_SANDSTONE)
                .textureColor(0, 0xFF99BBAA)
                .find())
        .paint(SquareColumnPrimitive.SURFACE_LAMP, XmPaint.finder()
                .disableAo(0, true)
                .disableDiffuse(0, true)
                .emissive(0, true)
                .texture(0, XmTextures.WHITE)
                .textureColor(0, 0xFFDDFFFF)
                .find())
        .apply(s -> { 
                SquareColumnPrimitive.setCutCount(1, s);
                SquareColumnPrimitive.setCutsOnEdge(true, s);})
        .releaseToImmutable();

final Block column = new PillarBlock(FabricBlockSettings.of(Material.STONE).build());
Identifier id = new Identifier(NiceBlocks.MODID, "square_column");
Registry.BLOCK.add(id, column);
Registry.ITEM.add(id, new BlockItem(column, new Item.Settings().maxCount(64).group(ItemGroup.BUILDING_BLOCKS)));

BlockTest<SimpleModelState> joinFunc = ctx -> {
    final BlockState fromBlock = ctx.fromBlockState();
    final BlockState toBlock = ctx.toBlockState();
    return fromBlock == toBlock
            && fromBlock.contains(PillarBlock.AXIS)
            && fromBlock.get(PillarBlock.AXIS) == fromBlock.get(PillarBlock.AXIS);};

final Function<BlockState, SimpleModelStateFunction> stateFunc = bs -> SimpleModelStateFunction.builder()
            .withDefaultState(SimpleModelState.AXIS_FROM_BLOCKSTATE.apply(defaultState.mutableCopy(), bs))
            .withJoin(joinFunc)
            .build();

XmBlockRegistry.addBlockStates(column, stateFunc);