Hair Particles
Hair particles can be used to add "hair" to a character, grass for the environment, or to duplicate objects across an area - like repeating buildings for a city. Keep in mind that particles are only visible in Object mode.
- With the object selected, go to the "Particles" tab of the properties panel
- Click on the + icon to add a particle system
- Change the type from "Emitter" to "Hair"
- Adjust the length and number of the particles as needed
- Don't forget the particles are only visble in Object mode
- Add the minimum amount of particles needed to get the desired visible effect - too many particles can cause the file to lag drastically
- Adjust the thickness of the hair particles under "Hair Shape" and "Diameter Root" (the shape is only visible with the Cycles engine in render shading)
- Experiment with the source settings to control how the particles are distributed
- Add a material for the particles:
- In the "Materials" tab, add a material to the plane for the ground color
- If the grass should be a different color, create a second material for the grass
- Double-click on the material names to rename descriptively
- In the "Particles" tab, under the "Render" subpanel, click in the field next to "Material" to select the correct material (if the object has only 1 material, it will be selected by default)
- Create a collection with objects named descriptively
- Make sure the origin of each object is at the bottom
- Give each object a material
- Arrange the objects in the center of the grid
- Select the objects in Object mode
- Shift+S → "Cursor to World Origin"
- Shift+S → "Selection to Cursor"
- Adjust the position/rotation of the objects as needed
- Apply the scale and rotation (Object → Apply → Scale & Rotation) or use CMD+A
- Select the object with the particles system (ie. the ground)
- In the particles properties panel, check "Advanced"
- In the "Render" subpanel of the particles panel, change "Render As" to Collection
- Under the "Collection" subpanel, select the collection
- Check "Rotation" and then select the correct orientation for your collection - usually this will be "Object X"
- Choose collection mode:
- Whole Collection - the entire collection acts as a single particle
- Pick Random - objects from the collection are randomly placed as individual particles
- Under "Render" deselect "Show emitter"
- Adjust the particle numbers and source settings as needed
Having too many particles in a scene can really slow down the performance of a file. Apply particles just where they are needed to minimize lagginess (ie. if the camera will be stationary, try just having the particles in the view of the camera, or just up close, instead of covering an entire ground plane).
- Add a particle system like above, but wait to change the number/length of particles
- In "Edit" mode, create a vertex group where the hair should be located:
- Select the necessary faces
- Setup and look the camera
- Select the vertices that should be inside the group
- or select the inverse and invert the selection
→
- In the "Object Data" tab of the properties panel, under "Vertex Groups", click on the + icon
→
- Select "Assign" so that the selected faces become part of the group
- Double-click on the group name to rename descriptively
- In the Particles tab of the properties panel, scroll down towards the bottom and expand the "Vertex Group" subpanel
- Next to "Density" click in the empty field and select the vertex group
- Adjust the particles settings as needed
Sometimes you may want forces like gravity or wind to act upon your particle system.
When using your own custom object or collection as the particles, add the materials as normal in the materials tab for each particle object. To add a material to the default grass/hair path, use the steps below.
- In the "Materials" tab, add a material to the particle system's object (ie. ground plane, animal, tree or etc.) and choose a base color
- If the grass should be a different color, create a second material for the grass
- Double-click on the material names to rename descriptively
- In the "Particles" tab, under the "Render" subpanel, click in the field next to "Material" to select the correct material (if the object has only 1 material, it will be selected by default)