Back to Tutorials

# Stickman & Elemento FAQ - Create Figures and Graphics

1. What's the difference between run-time and design-time?
2. What are variables?
3. What are properties?
4. What are expressions?
5. When is an expression calculated?
6. What are references?
7. What is the difference between expression programming and normal programming?
8. What is required to make a figure work with walk tool?
9. How do I group objects?
10. What is a matrix node?
11. How do I link colors together?
12. How do I create a background?
13. How do I bind the graphics to the skeleton?
14. What's the difference between 'Draw Order' and 'Variables'?
15. How do I use the expression language?
16. Where can I find detailed information about each expression function?
17. What happens to the name of a switch node in Stickman?

## Easy

### 1. What's the difference between run-time and design-time?

We can compare an Elemento figure with a car.
When we repair a car engine, the car should be turned off.
It's the same for figures. You can only make changes to the construction when the
figure is in design-time. But you can change a property at run-time, like driving a car.

### 2. What are variables?

A variable is the building block in Elemento.
There are many different kind or variables.
Each type of variable got a set of properties.
The properties can be programmed with expressions.

### 3. What are properties?

An ellipse, for example, got a property 'Width'.
Each property controls the look or behaviour of the variable.

### 4. What are expressions?

An expression is a kind of a law that controls the property of a variable.
When some of the variables that the expression depends on change,
the expression is calculated and the result is assigned to the property.

### 5. When is an expression calculated?

An expression is only calculated only when it's necessary.
From an outside view, it behaves like it was calculated all the time.

### 6. What are references?

A reference is a simple system to link the value of one property to another.
This is only happening at design time, since expressions replace the references at run time.

## Medium

### 7. What is the difference between expression programming and normal programming?

In normal programming, the computer executes one sentence at a time.
To do something multiple times you need a control loop.
Imagine a system where everything can suddenly change.
To make sure everything is working correctly in a such system, you need a control loop
that checks every value and sees if it is ok.
The problem with normal programming is that it doesn't work well with these kind of systems.

With expressions you tell the computer to 'do this all the time'.
Elemento does a sophisticated analyze of all expressions in a figure to find
out how to use as low CPU capasity as possible.
Instead of checking each value, the system itself finds out when something has changed.
Using the analyze, Elemento can now update only the expressions necessary.

### 8. What is required to make a figure work with walk tool?

This tutorial describes how to make a figure compatible with walk tool:
Online Tutorial - Offline Tutorial

### 9. How do I group objects?

Use a matrix node or a visibility node.
The matrix node allows all sub nodes to move when you move the matrix.
The visibility node can show or hide all sub nodes.

### 10. What is a matrix node?

A matrix node can move, rotate or resize the coordinate system of sub nodes.
The matrix is a mathematical tool for solving linear equations.
One important behaviour of matrix nodes is that they can compensate for change in the coordinate systems.
For example, when a figure picks up an item, the coordinate system for the item is changed from world coordinates to the container coordinate system.
You don't need to understand them completely to use them, they just works!
Just think of them as a way to 'move things together'.

### 11. How do I link colors together?

Select each shape that you will link to the brush, select the brush property,
right-click and choose 'Add Brush Reference'.

### 12. How do I create a background?

You can either draw the background with Elemento or use a drawing software like Photoshop.
To import from Photoshop, save the drawing as PSD file and use File->Import->Photoshop Layers.

### 13. How do I bind the graphics to the skeleton?

If you have created control points and grouped the graphics into matrix nodes, you can use
Create Skeleton And Attach Graphics.
If you want to have more control, you can select each matrix node and use the 'Attach' action.
Video Tutorial 1
Video Tutorial 2
Video Tutorial 3
Video Tutorial 4
Video Tutorial 5
Video Tutorial - Create Skeleton And Attach Graphics

### 14. What's the difference between 'Draw Order' and 'Variables'?

'Variables' shows all objects while 'Draw Order' shows the display order of the visible elements.
For example, a bone element constrains the distance between two control points, but it is not visible.
Therefore, you will only find the bone element under 'Variables'.

### 15. How do I use the expression language?

The expression language are similar to formulas found in spread sheet.
Read the chapter 'Expression Programming' in the manual:
Manual

### 16. Where can I find detailed information about each expression function?

In Elemento, goto View->Object Browser.