Sources, forces and colliders
Blaze Emitter
Section titled “Blaze Emitter”A Blaze Emitter adds fuel, smoke, heat and flame to the solver. The shape can be a sphere, box or cylinder, a mesh surface or volume, a curve, points, or a VDB volume.
- A sphere, box or cylinder placed by an object takes that object’s size: an Empty’s display size times its scale, or any other object’s bounding box.
- It has settings for Fuel, Smoke, Temperature, Flame and Velocity.
- A moving source leaves a trail (Motion Inherit).
Mesh sources
Section titled “Mesh sources”| Shape | How it is voxelized |
|---|---|
| Mesh Surface | The mesh’s triangles are voxelized on the GPU into a shell, whose thickness is set in voxels. |
| Mesh Volume | A closed mesh is filled. |
| Points | Mesh vertices, a point cloud or Geometry Nodes points, each with its own velocity. |
| Volume Object | A Volume object’s VDB file: density, temperature and fuel grids. |
An evaluated mesh includes modifiers, Geometry Nodes and instances.
Use Attributes
Section titled “Use Attributes”With Use Attributes on, attributes or grids on the source drive the emission:
| Attribute | Effect |
|---|---|
density and fuel |
Scale the emitter’s rates. |
temperature |
Scales the emitter’s temperature. Set to Kelvin, it is the absolute temperature. |
velocity |
Sets the emission velocity. |
The Burning Object template uses a temperature factor that is 1 only along the base of the prop, so the fire has to climb.
Forces
Section titled “Forces”| Force | What it does |
|---|---|
| Gravity | Gravity. Buoyancy scales with it. |
| Wind | Global, or local with a radius. |
| Vortex / Tornado | Swirl and suction about an axis, speed bounded. |
| Turbulence / Curl Noise | Curl-noise acceleration. |
| Shockwave / Explosion | A sphere, hemisphere or shaped charge. It adds heat and fuel. |
| Air Drag | Damps the velocity. |
| Thermal Buoyancy | An extra lift on hot gas. |
| Attractor | Pulls or pushes gas toward a point. |
| Curve Path | Flow and pull along a curve. |
Blaze also reads a Field Wrangle for your own per-voxel code. See Wrangles.
Colliders
Section titled “Colliders”| Collider | What it does |
|---|---|
| Object Collider | Sphere, box or mesh. Moving objects push the gas. |
| Ground Plane | A flat floor. |
| Kill Volume | Removes gas inside it. |
| Blaze Outflow | Removes chosen channels (smoke, fuel and so on) inside or outside a box, sphere or object. Lets gas leave through a region instead of bouncing back. |
Mesh colliders are voxelized exactly from their evaluated triangles, with no sample limit. A closed mesh is solid inside, and a moving or deforming one pushes the gas with its own surface velocity.
Pockets of gas that are sealed in by obstacles are filled in as solid rather than solved, since nothing can flow in or out of them.
Limits
Section titled “Limits”The scene tables (emitters, points, explosions, curve forces and colliders) are sized from the scene. Anything over the safety limits is reported in the solver warnings rather than dropped silently.
Every setting is listed in the Emitters, Forces and Colliders references.