I have had some troubles with blockstates in the past and when you think you got it all, the suddenly a weird bug appears.

I have 2 slabclasses 1 for 16 color blocks and 1 for some stone blocks.

They have both 2 variants. The color slab has HALF and COLOR. The stoneslab class has HALF and VARIANT

 

I had both coded both more or less the way the main issue is in the rendering method here:

for color slab:

@Override
    public void registerModels() {
		
    	if (!isDouble()) {
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 0, "color=white,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 1, "color=orange,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 2, "color=magenta,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 3, "color=light_blue,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 4, "color=yellow,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 5, "color=lime,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 6, "color=pink,half=bottom");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 7, "color=gray,half=bottom");
    	}
		
	}

and for the stone slab:

    @Override
    public void registerModels() {
		
    	if (!isDouble()) {
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 0, "half=bottom,variant=limestone_raw");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 1, "half=bottom,variant=marblestone_raw");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 2, "half=bottom,variant=limestone_cobble");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 3, "half=bottom,variant=marblestone_cobble");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 4, "half=bottom,variant=limestone_brick");
		Main.proxy.registerItemRenderer(Item.getItemFromBlock(this), 5, "half=bottom,variant=marblestone_brick");
    	}
		
	}

Now you can see that the color slab has set the "color" variant first and then the "half" variant

The stone class has it vica versa. I had it first in the same order has the color slab class but then i got those errors in the console it can't find an item model. Swapping the variant here solved the problem.

Yet i don't understand why. Here are both blockstate files.

For the terracotta brick slabs (part1):

{
    "forge_marker": 1,
    "defaults": {
        "textures": {
            "top": "#all",
            "bottom": "#all",
            "side": "#all"
        }
    },
    "variants": {
        "half": {
            "bottom": {
                "model": "minecraft:half_slab"
            },
            "top": {
                "model": "minecraft:upper_slab"
            }
        },
        

        "color": {
            "white": {
                "textures": {
                    "all": "tem:blocks/terracotta_white_brick"
                }
            },
            "orange": {
                "textures": {
                    "all": "tem:blocks/terracotta_orange_brick"                    
                }
            },
            "magenta": {
                "textures": {
                    "all": "tem:blocks/terracotta_magenta_brick"
                }
            },
            "light_blue": {
                "textures": {
                    "all": "tem:blocks/terracotta_light_blue_brick"
                }
            },
            "yellow": {
                "textures": {
                    "all": "tem:blocks/terracotta_yellow_brick"
                }
            },
            "lime": {
                "textures": {
                    "all": "tem:blocks/terracotta_lime_brick"
                }
            },
            "pink": {
                "textures": {
                    "all": "tem:blocks/terracotta_pink_brick"
                }
            },
            "gray": {
                "textures": {
                    "all": "tem:blocks/terracotta_gray_brick"
                }
            }
        }
        
    }
}

and here the stoneslabs:

{
    "forge_marker": 1,
    "defaults": {
        "textures": {
            "top": "#all",
            "bottom": "#all",
            "side": "#all"
        }
    },
    "variants": {
        "half": {
            "bottom": {
                "model": "minecraft:half_slab"
            },
            "top": {
                "model": "minecraft:upper_slab"
            }
        },
        

        "variant": {
            "limestone_raw": {
                "textures": {
                    "all": "tem:blocks/limestone_smooth_top"
                }
            },
            "marblestone_raw": {
                "textures": {
                    "all": "tem:blocks/marblestone_smooth_top"                  
                }
            },
            "limestone_cobble": {
                "textures": {
                    "all": "tem:blocks/limestone_cobble"
                }
            },
            "marblestone_cobble": {
                "textures": {
                    "all": "tem:blocks/marblestone_cobble"
                }
            },
            "limestone_brick": {
                "textures": {
                    "all": "tem:blocks/limestone_brick"
                }
            },
            "marblestone_brick": {
                "textures": {
                    "all": "tem:blocks/marblestone_brick"
                }
            }
        }
        
    }
}

 

As you can see the are structured identical

Perhaps there is something i don't see yet.

Variants in ModelResourceLocations and blockstates files are simply strings (despite Forge's format providing a way to specify per-property behaviours in any order), they need to match exactly. Minecraft always sorts properties in alphabetical order to form variant strings (unless you provide an IStateMapper that does otherwise) and Forge's blockstates format also performs this sorting for the properties you specify.

Aha this alphabetical order does make sense. I didn't think of that. I was wondering why it behaved so illogical. Perhaps i will use IStateMapper.

I used it once before. I had this issue multiple times before and switching the variants place fixed it, but never understood why.

Good to know. Thank you.

5 hours ago, winnetrie said:

Aha this alphabetical order does make sense. I didn't think of that. I was wondering why it behaved so illogical. Perhaps i will use IStateMapper.

I used it once before. I had this issue multiple times before and switching the variants place fixed it, but never understood why.

Good to know. Thank you.

 

Using an IStateMapper to change the property order will mean that you can't use Forge's blockstates format to its full extent, you'll need to use fully-specified variants like in the basic Vanilla format.

 

You can also use an IStateMapper to create property strings in the regular format when registering your models, like I do here, here and here.