Scattering Assets

engon comes with a scattering system that can be used to spawn a predefined preset or change options on how the scatter will be spawned. You can find scatter related options in the Scatter panel. Scatter panel is further split to sub-panels where the individual settings can be found.

Watch how to use the Scatter system

pps - polygoniq particle systems

polygoniq particle systems are Blender particle systems that are managed through the scatter sub-panel. Using scatter functions to create and manipulate particle systems ensures correct naming and enables all of the additional functions to work. Those particle systems have names prefixed with pps_ to differentiate them from other. Name of the particle system matches name of the instance collection and of the modifier in modifier stack.

Why is the panel empty?

Scatter sub-panel operators will not show up if the target object is not suitable for particle systems. For example you cannot create a particle system on a instanced collection object, volume, curve, etc.

Scatter sub-panel

Main section of scatter panel consists of target object, buttons to add, remove or rename active particle system and a list that displays all presets on the target object.

• Target is a container object for the particle systems. This object's visibility can be toggled by the buttons next to its name. Target object is the same as active object.
• Buttons above the list can be used to manipulate presets. + is used to create new presets, - removes active particle system. Pencil icon renames the particle system. Presets List displays all the polygoniq particle systems on the target object. Visibility of each layer can be toggled for render and viewport individually.

Tip

Some botaniq presets come with multi-layer particle systems. You can create these by yourself too. Create multiple empty particle systems and customize each layer separately. For example one layer can contain grass, second one trees, third rocks, etc.

Spawning preset

Use either pre-made particle system or a empty particle system can be spawned. Spawn particle systems using the engon Asset Browser or E key. You can filter by particle systems filter.

Particle settings options are located on the top right of the engon Asset Browser header, in the Asset Spawn Options.

• Display Type lets you to swap between Textured, Solid, Wire and Bounds shading modes for the viewport.
• Display Percentage modifies the percentage amount of particles shown in the viewport.
• Link instance collection to scene checkbox. When enabled (default), individual models scattered in the presets will be added to the scene 10 meters below the world origin (0, 0, 0). This is useful for editing the objects directly.
• Enable Instance Collection checkbox. This option is only relevant if Link Instance Collection to Scene is enabled. If disabled (default), the spawned models in the linked instance collection will be hidden and will not appear in renders.
• Include base material checkbox. If set to true, a base material is loaded with the particle system and added to the target object as active.
• Preserve density checkbox. Each preset has a set number of models that is based on the area of the target object. If this option is on, your target object will get covered evenly regardless on its size on spawn.
• Maximum Particle slider modifies the maximum amount of particles to be spawned.

All particle systems you spawn with Link instance collection to scene enabled are automatically added into engon_particle_systems collection.

Particle Settings

Sub-panel containing convenient and useful settings from particle systems at hand.

• Number is a count of particles generated on the object.

• Seed property randomizes the distribution.

• Scale resizes all objects in the system.

• Scale Randomness introduces random factor into the scale.

• Orientation axis defines how the objects should be rotated. Generally you will need two options. Ground Z where objects rotate around vertical axis. And a Normal option which rotates the particles rotate around the normals of the object.

• Randomize is an random offset from the orientation axis.
• Phase is a rotation around the chosen axis.

• Random phase introduces some random offset into the rotation around chosen axis.

• Particles per m^2 can be used to set the number of particles that will appear on 1x1m area.

• Max particles limits the number of particles for the Recalculate density button.
• Recalculate density automatically recalculates the density based on the area of the underlying mesh depending on the Particles per m^2 value. Useful after scaling emitter.

Visibility Settings

Sub-panel that can be used to tweak viewport visibility settings of polygoniq particle systems across the scene or for the active particle system.

• Display lets you choose how much particles to display in percents.
• Display as allows selecting how the instanced objects are displayed in scenes.
• Displayed particles is the count of currently displayed particles.

To manage viewport visibility across the scene you can use the Manage Viewport Visibility operator.

Tip

Visibility settings are useful to optimize viewport performance. To maximize performance set the display to the minimal feasible number and the display as to wireframe. This will not affect the render at all.

Weight Painting

botaniq comes with simplified weight painting to enable even more precise customization of the particle system location.

There are two weight painting options. You can either paint density or length. Clicking the brush button to corresponding option enables weight paint mode. To invert a weight paint masks, use the button. To duplicate a mask, use the button.

More information about weight painting (brushes, vertex groups, ...) is available in the official blender documentation

Warning

In order for weight paint to work properly you must have the target object subdivided enough as each vertex carries information about how many objects should spawn near it. (Red=Density 1, Blue=Density 0)

Texture

Similar to weight painting, textures can be used to affect the density and size of particles in the particle system. From there, you can customize the texture source, and adjust how much the texture affects particle density with Density factor and particle scale with Scale factor. To adjust the scale and position of the texture, you can tweak the properties in texture mapping.

The Texture sub-panel is visible only when the particle system uses a texture to control density or size.

Adding a texture to a particle system

You can add textures to a chosen particle system by going to the Properties Editor - Particles - Texturesand create a new texture or add an existing one. Then, in Properties Editor - Texture - Influence check the Density and Physics Velocity checkboxes. Texture Panel in Engon should appear now.

Objects (Instance collection)

Sub-panel that contains information about all of the objects in the instance collection from where objects are being scatter.

• Refresh updates the scatter if you edited the collection contents yourselves in outliner.
• Append Selection adds currently selected objects into the active scatter.
• - removes active scatter object from the collection.
• Asset count represents the chance of the object in collection being generated. For example, if you set object A’s count to 10 and object B’s count to 1, there is a 10:1 chance that object A will appear. In praxis, this means you will have 10 models of grass for every 1 model of a flower.
• Preview is displayed for the selected object if it is known to engon. You can click the magnifying glass icon to open detailed description of the asset for more information.
• Scale can be used to manipulate the scale of the individual objects.