HurricaneTutorial 05
Cloth Tearing Simulation with Wind in Blender
Rip a cloth apart with wind: paint a tear mask with Hurricane Tools, cut it with Split, sew it with a breakable Weld and grow a Directional Wind.
In this tutorial we hang a cloth from one side and let a growing wind rip it apart along seams we design ourselves, while the pinned edge holds on.
You will build a procedural tear mask by stacking Tools (Voronoi Edges, Noise and a Gradient), cut the cloth with Split, sew it back with a Weld constraint that breaks when stretched, drive everything with an animated Directional Wind and finish by turning the particles into a cloth mesh.
Step by step
-
Add a plane, stand it up and stretch it to 4 × 2 m (scale X to
2). In Edit Mode, add a loop cut and Subdivide it with Number of Cuts set to 35, so the cloth has enough vertices to fold.Click New Simulation in the Hurricane panel to set up the scene (with Create HurricaneFloor enabled), then open Add Emitter and choose Cloth under Material Presets: the plane turns into particles.
To hang the cloth, go back to Edit Mode, select three vertices on the left edge (both corners and the middle one) and, in Particles → Pin, click Static. These pins hold the cloth in place. Press Play: the cloth drops and hangs from its pins. It bends, but it can't tear yet.
-
Cloth never tears on its own, so first you paint the seams with Tools (Particles → Emitter → Tools). Click + in the list and build this stack:
- Voronoi Edges: its eye icon previews the attribute, and the white lines are your future cracks. Raise Voronoi Scale (about 2.1) and Noise Strength (about 0.44) for smaller, wobblier cells, then lower Scale X under Transform (to -0.050) to stretch them into long horizontal lines.
- Noise: it will break up the regular Voronoi lines so the tear looks organic.
- Mix Attributes: Attribute Input 1
voronoi_edges, Attribute Input 2noise, Blend Type Multiply. - Gradient: place it with Translation X and Scale X (1.190) so it goes black on the left and white on the right. Once multiplied, black means no cracks, so the pinned edge stays whole.
- A second Mix Attributes: Attribute Input 1
mix_attributes, Attribute Input 2gradient, Multiply. Its preview shows the final mask, with no cracks near the pins.
Nudge the gradient's Translation X (final value 1.558) to set how wide that crack-free strip is. Finally, rename the Attribute Output of the last mix to
maskout: it's the attribute the Split tool will cut along.What Tools are
Tools are procedural modifiers that stack on the emitter. Each one writes an attribute, like a noise, a Voronoi pattern or a gradient. You can send it to the Particles or to the Constraints, and use it to mask emitters. Here, it decides where the cloth tears.
-
Add a Split tool and type
maskoutin its Attribute field: it cuts the cloth along those seams. A red warning appears under the tools list. If you play anyway, the cut pieces burst apart, because there is no Weld constraint yet.While you're in Tools, refine the mask:
- In the Noise tool, squeeze its color ramp (bring the stops close together, around 0.5–0.6) so only the strongest noise lets cracks through.
- In the Gradient tool, move the black stop of its color ramp (to Pos 0.176) to sharpen the band.
Every test still bursts apart: the mask is fine, what's missing is the Weld.
Split needs a Weld
The panel warns: "Split cuts need a Weld constraint or Particles Self Collision off: the cut pieces burst apart at birth". Without the Weld, the cloth explodes as soon as the simulation starts.
-
A Weld constraint sews the cut particles back together so the cloth holds as one piece, and with a Breaking Type each seam snaps when it stretches too far. In Constraints, click Add Constraint to create a second constraint and set its Constraint Type to Weld.
Now the wind: in HEL, click + in Particle HEL Scripts and add Directional Wind. Rotate the Wind Guide to aim the wind.
Back in the Weld constraint, set Breaking Type to Relative Distance: each seam snaps once it stretches past the Max Elongation Ratio.
The cloth now holds together, but gravity drags it down. In Simulation → Simulation Settings, set Gravity Z to 0: without gravity, only the wind moves the cloth.
The wind is global
Limit to Guide is off, so the wind affects the whole scene. Moving the Wind Guide is just for a clearer view; its rotation is what sets the direction.
-
In Directional Wind, raise Turbulence (to 3.210) for stronger gusts: the cloth flaps harder, but the seams still hold. So animate Wind Strength: keyframe 5 at frame 0 and 14 at frame 132, so the wind keeps growing. Then, in the Weld constraint, lower Max Elongation Ratio to just above one (1.020) so the seams snap sooner.
Play again: as the wind builds up, the stretched seams begin to give way. The cloth tears only where the mask allowed, while the pinned side holds on. Set the timeline End to 204.
Finally, in Surface → Surface Generation, choose Cloth Meshing to generate a mesh from the particles. In Mesh Settings, Merge By Distance On/Off joins the seams that didn't tear and Smooth Edges softens the broken edges. A slightly larger merge Distance (from 0.001 m to 0.005 m) closes the gaps along the seams.
You now have a cloth that rips only where you designed it: Tools paint the mask, Split cuts the seams, a breakable Weld sews them and Directional Wind tears them open.