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 # RAMaterialCollection

 Last update: 17.07.2025 

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### *class* RAMaterialCollection

Rocky PrePost Scripting wrapper for the collection of materials in a project.

This wrapper corresponds to the “Materials” item on the project’s data tree. Retrieve the [`RAMaterialCollection`](#generated.RAMaterialCollection) from a [`RAStudy`](RAStudy.md#generated.RAStudy) via:

```python
material_collection = study.GetMaterialCollection()

```

Instances of the [`RAMaterialCollection`](#generated.RAMaterialCollection) class act as regular Python lists and can be iterated on, individual materials accessed and deleted via index, etc:

```python
material_1 = material_collection.AddSolidMaterial()
material_2 = material_collection.AddFluidMaterial()
material_2 = material_collection[3]
del material_collection[2]

```

Items in this list are of type [`RASolidMaterial`](RASolidMaterial.md#generated.RASolidMaterial) and [`RAFluidMaterial`](RAFluidMaterial.md#generated.RAFluidMaterial).

**Methods:**

NameDescription[`Clear`](#generated.RAMaterialCollection.Clear)()Remove all items from the list.[`GetBulkSolidFraction`](#generated.RAMaterialCollection.GetBulkSolidFraction)()Get the value of "Bulk Solid Fraction".[`GetDefaultMaterials`](#generated.RAMaterialCollection.GetDefaultMaterials)()Deprecated: Use [`GetDefaultSolidMaterials()`](#generated.RAMaterialCollection.GetDefaultSolidMaterials) instead.[`GetDefaultSolidMaterials`](#generated.RAMaterialCollection.GetDefaultSolidMaterials)()Get a list with the default solid materials, in order of Particle, Belt and Boundary.[`GetFluidMaterial`](#generated.RAMaterialCollection.GetFluidMaterial)(material\_name)Get the fluid material with the given name.[`GetMaterial`](#generated.RAMaterialCollection.GetMaterial)(material\_name)Deprecated: Use [`GetSolidMaterial()`](#generated.RAMaterialCollection.GetSolidMaterial) instead.[`GetSolidMaterial`](#generated.RAMaterialCollection.GetSolidMaterial)(material\_name)Get the solid material with the given name.[`New`](#generated.RAMaterialCollection.New)()Deprecated: Use `Add{Solid, Fluid}Material()` instead.[`Remove`](#generated.RAMaterialCollection.Remove)(item)Remove an item from the list.[`SetBulkSolidFraction`](#generated.RAMaterialCollection.SetBulkSolidFraction)(value)Set the value of "Bulk Solid Fraction".<a id="generated.RAMaterialCollection.Clear"></a>

#### Clear()

Remove all items from the list.

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#### GetBulkSolidFraction()

Get the value of “Bulk Solid Fraction”.

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#### GetDefaultMaterials()

Deprecated: Use [`GetDefaultSolidMaterials()`](#generated.RAMaterialCollection.GetDefaultSolidMaterials) instead.

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#### GetDefaultSolidMaterials()

Get a list with the default solid materials, in order of Particle, Belt and Boundary.

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#### GetFluidMaterial(material\_name: str)

Get the fluid material with the given name.

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#### GetMaterial(material\_name: str)

Deprecated: Use [`GetSolidMaterial()`](#generated.RAMaterialCollection.GetSolidMaterial) instead.

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#### GetSolidMaterial(material\_name: str)

Get the solid material with the given name.

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#### New()

Deprecated: Use `Add{Solid, Fluid}Material()` instead.

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#### Remove(item: T)

Remove an item from the list.

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#### SetBulkSolidFraction(value: Union\[str, float\])

Set the value of “Bulk Solid Fraction”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.