Particles Module

Particles Creation

In this module we will be able to add debris/dust or Smoke to our simulations. This will add a lot of detail.

We have several options in the particle creation module, Broken and Motions, or using both options at the same time.

To understand the broken option, we must first know the following: Every time we fracture an object in RBDLab, the Addon detects which neighbors each chunk has. RBDLab is able to detect which chunks surround other chunks, and in this way obtain very valuable information. For example, RBDLab 1.4 is now able to detect with great reliability, which chunk has broken, ( by breaking its constraints ) thanks to the fact that we know which chunks are its "neighbors". It is also very useful to speed up the Constraints creation process.

Without Particles

Here we can see a simulation without the use of particles.

With Particles

Here the same simulation, with Debris and Dust.

Motion Creation

Using the Motion Creation option, RBDLab will calculate the velocity of each chunk to generate the particles. In the example we have, there is a wall with the chunks still, with velocity 0. When they receive the impact of the sphere, the chunks that break fly away and gain velocity. When the speed is higher than indicated in the Velocity Threshold, the Debris are generated.

Let's review the Motion creation options:

Velocity Threshold: Here we indicate what minimum velocity the chunks must have for the particles to be generated. The calculation is done for each chunk independently, so the creation of particles will also be independent of each chunk, creating dynamic and very realistic Debris.

PS Limit: Here we indicate the amount of emitters that each chunk will have. There are situations where a chunk can emit particles more than once. Let's suppose a chunk that has fallen to the ground, has stopped, and instantly receives the impact of another chunk and makes it gain speed again. If we set a PS Limit of 2, the chunk will generate particles twice, when it receives the first hit, and after it stops, when it receives the second hit. Normally this value is set to 1.

Use Selected Chunks: Using this option, we can make RBDLab add particles only to the chunks that we have selected in Viewport.

Force Updated: This option is used when we have created particles and then deleted them. For RBDLab to recalculate the information, we need to activate this option.


Broken Creation

This is a new option available as of RBDLab 1.4. As we indicated above, RBDLab calculates all the neighboring chunks of each chunk, so we can know exactly which pieces have "peeled off" when their constraints were broken.

This is extremely useful in examples like the one we see. A geometry that falls from a height, impacts and breaks. If we were to use the Motion option, it would begin to generate debris as soon as it starts to fall, since the pieces are gaining speed.

By using the Broken option, the particles will be emitted the instant the geometries break, never before.

Distance Threshold: Here we indicate from what distance between one chunk and another we consider that it has broken to emit particles. If we see that some chunks have only separated for an instant, but have not broken, we should raise the threshold to prevent those chunks from emitting particles.

Use Selected Chunks: As in Motion, this option is used to work only with selected chunks.

Broken & Motion

It may also be the case that we want to use both calculation options to ensure maximum accuracy when creating the particles.

It is as simple as selecting one of the options, holding down the Shift key and pressing the other option. That way we will have both options activated when generating the calculations.

Particles Settings

Once the particles are generated, we will have 4 submodules to work with them. In addition we will have options such as Filter Particles, Custom Debris or "Link Emitters new collection", let's review each option. 

In all the submodules, there is a tab that is always present, "Viewport Display", which is used to change certain display options. The way the particles are displayed, either by points, render (geometry) or nothing. The size, the selection of the geometry to be represented by the particles, etc...

Every change we make in these submodules, must always be applied using the UPDATE button.


Emission Submodule

In this submodule, we will have some options to configure the particle emission. The amount of particles or their duration.

There is also a tool called "Frame Offset" that allows to advance or delay the particle emission.

The particles have an emission duration configured by RBDLab. As long as the chunks have velocity, they will be emitting particles. This can be changed by activating the "Use end trails" option and setting the number of frames in which particles will be emitted in each chunk.

Physics Submodule

In this submodule, we can configure the speed and rotation of the particles. Their direction in the X,Y,Z axes or use the Timestep tool to give a "Slow Motion" effect to our particles.

Field Weights

Here we can configure how the scene forces affect our particles, increasing or decreasing the effect. We can also choose a collection of forces to work only with them.

Basic Debris

In the Basic Debris submodule we can add more detail to the basic debris created by RBDLab when generating particles. We can also change their materials.

Link Emitters new Collection

From this option, we can send our particles to a new collection. This way, we can hide the working collection and display only the particles. It is really useful for when we are going to render our scene. This way, we will be able to render by separate passes the geometry and the particles.

Filter Particles, Muted

From this option, we can mute the particles. You can select a section (or even a single chunk) and mute it so that it does not emit particles. It is very useful to be able to hide some particles that for artistic reasons we do not like how they have turned out.

Create Custom Debris

In this section, we can select any geometry (or several) and create our own collection to use as Debris.

We can also use the chunks generated with High Detail as Custom Debris.