Hello everyone,

 

I was wondering if someone would be so kind to explain a bit how IItemPropertyGetter works. Basiclly I have a block with over 60 variations using forge blockstate. Is it possible to render different model from blockstate based on ItemBlock NBT tags? If so, would anyone be so kind and explain?

 

Thank you in advance. 

So, IItemPropertyGetter gives you the following (client side) method:

public float apply(ItemStack stack, @Nullable World world, @Nullable EntityLivingBase entityIn)

 

Which includes the ItemStack, and presumably its NBT tags.  It must return a single floating point number, which is tied to a single "property name" (e.g. "Time" which is what the clock uses).  The Item's json file then must have these states in sequential order because minecraft goes "Ok, I need 12.9845" and starts at the top and looks for the first value that's larger than the IItemPropertyGetter's returned value and uses that "variant."  I discovered this by accident when trying to do something weird.

 

You can see an example implementation of my own here (using world information, not NBT):

https://github.com/Draco18s/ReasonableRealism/blob/master/src/main/java/com/draco18s/farming/item/ItemThermometer.java#L53

https://github.com/Draco18s/ReasonableRealism/blob/master/src/main/resources/assets/harderfarming/models/item/thermometer.json

Where each one of those specified models is a normal, standard, item model file (which can point to a block, just like any other block item model file).

https://github.com/Draco18s/ReasonableRealism/blob/master/src/main/resources/assets/harderfarming/models/item/temp_05.json

IItemPropertyGetter

allows you to specify properties (arbitrary

float

s) of an item based on the

ItemStack

, the current

World

(if any) and the

EntityLivingBase

that has the item (if any). The item model can query these properties and choose to render as a different model if they match certain values.

 

The wiki explains the item model format here. An override predicate will be

true

when the

IItemPropertyGetter

for the specified property returns a value >= the value specified in the predicate. An override will only be used if all of its predicates are

true

.

 

IItemPropertyGetter

is mostly used for models that can change dynamically (e.g. pulling back a bow, casting a fishing rod, blocking with a shield or breaking an elytra). If your item has fixed subtypes you're probably better off using

ItemMeshDefinition

, which allows you to map an

ItemStack

to an arbitrary

ModelResourceLocation

. Make sure every possible

ModelResourceLocation

returned by the

ItemMeshDefinition

has been loaded by a blockstates file or

ModelBakery.registerItemVariants

.

 

If you have a large number of similar variants, you could consider creating your own

IModel

like

ModelDynBucket

that generates the shapes and textures at runtime.

I also have an example of that here with model registration here and I think this class was used somewhere along the way as well.

Thank you both. That was helpful. It sounds like ItemMeshDefinition is exactly what I need.