Adds the ability to force a block to use a custom item model.

src/main/java/appeng/bootstrap/BlockDefinitionBuilder.java

@@ -10,9 +10,11 @@ import java.util.function.Function;
 import java.util.function.Supplier;
 
 import net.minecraft.block.Block;
+import net.minecraft.client.renderer.block.model.ModelResourceLocation;
 import net.minecraft.creativetab.CreativeTabs;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemBlock;
+import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.common.registry.GameRegistry;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
@@ -119,6 +121,22 @@ class BlockDefinitionBuilder implements IBlockBuilder
 		return this;
 	}
 
+	@Override
+	public IBlockBuilder useCustomItemModel()
+	{
+		rendering( new BlockRenderingCustomizer()
+		{
+			@Override
+			@SideOnly( Side.CLIENT )
+			public void customize( IBlockRendering rendering, IItemRendering itemRendering )
+			{
+				itemRendering.model( new ModelResourceLocation( new ResourceLocation( AppEng.MOD_ID, registryName ), "inventory" ) );
+			}
+		} );
+
+		return this;
+	}
+
 	@Override
 	public IBlockBuilder item( Function<Block, ItemBlock> factory )
 	{

src/main/java/appeng/bootstrap/IBlockBuilder.java

@@ -27,8 +27,13 @@ public interface IBlockBuilder
 
 	IBlockBuilder rendering( BlockRenderingCustomizer callback );
 
+	/**
+	 * Forces this block's item to uses a custom model, instead of using the default block state as the item model.
+	 * The model has the same name as the registry name.
+	 */
+	IBlockBuilder useCustomItemModel();
+
 	IBlockBuilder item( Function<Block, ItemBlock> factory );
 
 	<T extends IBlockDefinition> T build();
-
 }