Blender 3D Animation Nodes: Force Overview

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In this comprehensive article, we will delve into the world of force in Blender's Animation nodes system, focusing specifically on version 2.83 and later releases.

What is a Node?

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Before diving headfirst into forces within Animation Nodes, it's essential to understand what an 'Animation node' actually represents. Simply put, an animation node can be thought about as a tiny procedural block that performs specific tasks or operations when connected together in larger graphs or networks. These nodes are the building blocks of complex animations and simulations in Blender.

What is Force?

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Force, within the context of Animation Nodes, refers to any influence exerted upon objects within an animation scene. Forces can be thought of as invisible forces that push or pull on objects over time. In essence, they govern how rigid bodies (rigids), soft bodies (softs), and other types of objects behave in a given simulation.

Types of Force

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There are several types of force nodes available within Animation Nodes:

1. Empty: This is the base type for all forces. It does nothing on its own but can be inherited from to create more complex behaviors.

2. Spring : A spring-like force that pushes two objects apart or together depending upon their distance and stiffness values.

3. Bend: Bends an object along a specified axis based on its strength value.

Creating Custom Forces

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While Blender comes with several built-in forces, sometimes you may need something more specific to your particular project requirements. Fortunately, Animation Nodes provides powerful tools for creating custom force nodes from scratch!

To do this:

1. Create a new node group by right-clicking in the Node Editor and selecting 'New' > 'Group'.

2. Inside the newly created node group:

- Connect an Empty Force node as your base.

- Use various operators (like Math, Vector) to manipulate its properties based on inputs from other nodes or constants.

Example: Simple Spring-like Custom Force

Let's say we want a simple spring-like force that pushes two objects apart when they get too close. Here is how you could achieve this:

1. Create an Empty node as your base.

2. Connect the 'distance' output of one object to the first input ('A') on another Math node set up with an operator like `abs()`.

3. Set a threshold value in the second input ('B'). If the distance between A and B is less than or equal to this, then we want our spring force active.

4. Connect these two outputs (threshold comparison result & distance) as inputs to another Math node set up with an operator like `ifelse()`.

- When true (i.e., objects are too close), output a strong repulsive force in the opposite direction of A towards B using Vector operators such as `-A * strength` or something similar.

5. Finally, connect this result back into one of your object's 'forces' inputs.

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In conclusion, forces play an integral role within Blender 3D animation scenes when working with rigid bodies and soft body simulations alike! By understanding how to use existing force nodes effectively combined with the power offered by Animation Nodes for creating custom behaviors on-the-fly; you'll be able to craft complex animations that were previously beyond your reach. Happy animating!

Blender 3d animation nodes force