Content:
A Blender scene with a geometry node setup to scatter instances in a 3D space. Specific features are highlighted in example collections:
- camera geometric culling
- density by object proximity
- delete by volume (or outside it)
- animation features
I have been using those rocks and debris many times for my sci-fi pictures. Tweak it at will!. That scene was built with Blender 3.6.4 it will work with Blender 3.6 LTS and further versions. It might work with previous versions but it might get hasardous results.
How to use it:
Pick one of the assets collections, or move up the various objects you want instancied into the Selected_Instances collection. They will be randomly scattered.
If you want an instance more frequently than others, duplicate it the appropriate number of times to increase its probability (So far, I can't make a proper node for this) and add it to the same collection.
You can edit the scattering surface at will, as well the delete volume. These trees are well suited for still pictures, they can be used to bring life to floating objects such as drifting and spinning.
Parameters:
Surface: the chosen object to scatter instances.
Collection: the chosen instances collection
Material: material assigned to all instances
Distance Min: the minimum distance between points (this is poisson disk sctarring here)
Density Max: raising this value will result in increasing the number of points
Density Factor: overall factor, zero is no points, one is full density
Min_Scale: Minimum size of instances
Max_Scale: Maximum size of instances
Magnitude: Global scale factor
Voronoi \ Noise: random formula. Voronoi will give more neat reasults while noise is more diffuse
Void effect: drives a non-uniform distribution pattern
random scale: sclae of voronoi and noise textures
Seed: Change all random values in the node tree
Diffusion Amplitude: how far points are scattered from the emitter
Diffusion Min: minimum diffusion value, engative value is allowed
Diffusion Max: maximum diffusion value
Camera_Culling: enable deleting instances outside the field of vision.
Camera: the chosen camera
Delete_by_Volume: enable deletion of instances inside an object.
Object: the chosen delete object.
+ Camera culling parameters:
Picture_Ratio: ex: 1920/1080 is 1.77
Frame_Scale: use it to expend the culling to avoid border pops. (default value is 1)
Focal_Lentgh: from the camera
Features:
- One large set of asteroids: small , medium and large rocks, with procedural shaders including bump.
- One set of ice: mixted sized with 2 procedural shaders including bump.
- One set of debris instances: no UVs for those objects, one simple shader.
- Fog Box: to add a volume shader to your scene.
Improvements:
- random distribution with poisson disk
- void effect
- Drift and spin animation nodes
- Fixed camera culling behind the camera
License: for any use, personal, educational or commercial.
