# Common properties of nodes — Material Maker documentation

# Common properties of nodes

The nodes will always have outputs that will be connected to the inputs of other nodes. They may also (and will probably) have parameters that can be modified in the user interface, and inputs to receive data from other nodes.

## Outputs

Nodes can have several outputs that represent the images they provide. Each node output can be connected to several node inputs. Each node output (and input) can be:

- a greyscale image (shown in grey)

- a color image (shown in blue)

- an RGBA image (shown in semi-transparent green)

- a 2D signed distance function (shown in orange)

- a 3D signed distance function (shown in red)

- a 3D texture (shown in fuchia)

Greyscale, color and RGBA inputs and outputs can be connected to each other and will automatically be converted when required.

2D signed distance functions have a specific preview that shows the associated signed distance field. They can be converted into greyscale images using the sdShow node.

3D signed distance functions have a specific preview that shows the lit 3D scene. They can be converted into a greyscale height map and a color normal map using the Render node.

Clicking on an output slot it will show the corresponding preview at the bottom of the node. When a node has several outputs, only one of them can be previewed at a time. The previewed output slot will has a circle around it, and clicking it again will hide the preview.

## Inputs

Inputs are images the node will transform (if any). An input is always connected to at most an output. Inputs generally have a default value that is used when it is not connected.

## Parameters

Parameters are used to configure nodes. The following types are supported:

- float parameters are used whenever a real number is needed. Float parameters have bounds, but it is possible to ignore them (at your own risk). To modify a float parameter, click in the text field and enter a new value, or click and drag left or right to decrease or decrease its value. When the lower or upper bound is reach, the value wil stick to it, but dragging again from there makes it possible to go beyond the limit.

- size parameters are power of two values for the image size. They are used when actually storing data in a texture, or when performing resolution dependent calculations such as convolutions. They are shown as drop down list boxes.

- enumerated parameters are used when nodes have different named options and shown as drop down list boxes.

- boolean parameters are shown as check boxes.

- color parameters are shown as Color selectors.

- gradient parameters are edited in dedicated editor widgets. Cursors can be added by double-clicking in the lower part of the widget, dragged left and right using the left mouse button, and removed using the right mouse button.

  The drop down list box can be used to select one of the 4 interpolation options. Double clicking in the upper part of the gradient editor will open a larger version of the widget to move cursors mode precisely.

  Finally, it is possible to drag and drop from the upper part of a gradient editor widget to another to duplicate the gradient parameter, or from any Colorize node variant in the library to a gradient editor widget.

## Randomness

Nodes that provide random patterns have an implicit seed parameter. It is not possible to edit it directly, but moving the node in the graph will change its value. It is possible to freeze the seed value using the small dice button in the node’s title bar in the graph.

Subgraphs also have their seed and transmit it to their children unless not configured to do so, or the children’s seeds are frozen.

## Modifying nodes

Most nodes in Material Maker can be modified, but they first have to be made editable. To do this, select a node, and use the Tools -> Make the selected nodes editable menu item or the Control+W keyboard shortcut.

When made editable, 3 buttons are shown at the bottom of the node:

- A pencil-shaped button to edit the node (the precise behavior of this button depends on the node type)

- A folder-like button to load an existing node template

- A floppy disk button to save the node as a template

To be reusable directly, templates must be saved in the generators directory in the install dir (or the addon/material_maker/nodes directory when using Material Maker as a Godot addon). All nodes templates saved in this directory are shown in the Tools -> Create menu.

It is absolutely not necessary to save newly created nodes as templates, but this makes them a lot easier to access and results in smaller material files (only references to the templates are saved and not the whole node description). Consequently, modifying a template without ensuring compatibility with the old version (i.e. removing or renaming parameters, removing or swapping inputs or outputs).