# Differences between Slices and Groups
## Slices
**Slices** are the buildup layer structure in a wall, roof or a ceiling panel. The **Slice outlines** (borders) are geometrically set.
Examples:
* In a roof buildup we talk about a **rafter Slice,** a **sheeting Slice** and **insulation Slice**. In a floor buildup we have **a joist Slice** and **subfloor Slice**.
The **Slices** facilitate the ease of inputting the materials by defining the **Slice outlines** for the material and speed up the positioning of the material within the **Slice thickness**.
You define your wall buildup and assign the thickness and properties of the **Slices** within the Wall, Floor and Roof modules.
Every **Slice** can be linked to the database as a **Slice Item** # containing structural and thermal properties for calculating the performance of a building.
With the assigned Properties in Floor and Roof each **Slice** has a texture set that is used for rendering the **Slice** in Open GL mode.
## Groups
**Groups** are used in the program to organize materials, regardless of their location in the wall, floor and roof. It is an advantage when generating drawings to be able to combine slices or create drawings of individual slices.
When placing materials in Roof, Wall and Floor Design modules, the program automatically assigns the material to the same **Group** according to the **Slice Outline** it is positioned within.
Typically, the rafter that is put into Slice 0 in a **Roof Slice Outline** automatically belongs to **Group** 0
In D-CAM you are able to combine different **Groups** of materials independent of the location of the **Slice**. Example: For generating specific lists or drawings.
In the Wall Guideline Editor it is necessary to be able to reference the placement of materials to materials of different slices for automatic positioning.
Example: If you are setting up a guideline for a board and batten wall- rain screen enclosure, you would place the board and batten into different **slices** and reference one of the other, but let them belong to the same **group** for creating a list and dimension take off info.
## Managing and Working with Slices and Groups
In Wall Design and Floor Design you are able to switch the individual **Slices** and individual **Groups** on or off.
In Roof Design you are able to switch the individual Groups on or off.
To be able to individually switch **Slice Outlines** and **Groups** is an advantage when placing materials in a **Slice Outline** with many **Slices** that have materials already present.
Example: If the OSB sheathing material is already present in Slice -1 and you have to place drywall into Slice 2 it is an advantage to be able to switch Slice and Group -1 off.
Wall Design, Floor Design and Roof Design\* offer the reshaping of each individual **Slice Outline**.
Example: If the OSB sheathing needs to have a set back around a door or Window of 1”, you are able to move the -1 Slice outline around the door and Window so when you place the OSB material it gets cut back automatically when placing the sheathing.
(\*In Roof Design you are able to change individual Slice Outlines with the function Roof Line Properties)
### Special Groups
**Group** 18 has been reserved for Auxiliary materials only.
Auxiliary Material is anything that is used for visualizing objects like windows, skylights, furniture and any other object you would like to see, but you don’t need a quantitative take off for lists or calculation. Auxiliary objects can be created and linked to the database. Any Item that has a # sign in front of it will be classified as a Auxiliary Item.
### Slice relation to Groups
All Wall, Floor and Roof Slices that can be visualized belong to **Group** 20. In D-CAM you are able to switch them on or off, or activate them all in one step.
**Groups** from 8 to 17 can be used to organize materials for different purposes.
### Project Data Dimension Takeoff from Slices
**Slice Outline** and volume are used for calculating area dimension take off, line length take off, and volume take off to generate data for the architectonical values.
### Summary
Groups and Slices are created automatically while working in the Wall, Floor and Roof modules.
The Dietrich’s program organizes the materials automatically when placing materials in the Wall-design, Floor-design and Roof-design modules.
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