FX Mesh Generator

Module: Art · Category: VFX · Tool ID: FXMeshGenerator

The meshes VFX work is built on — sword slashes, energy beams, shockwave rings, impact discs, shield domes, tornado helixes — generated parametrically with UV flow and vertex alpha baked in, previewed live, validated against budgets, and saved as Static Meshes ready for Niagara.

The value is not just the shapes. It is that the UV flow direction and the alpha mask are baked into the mesh, so the material can be trivial: scroll a texture along V and multiply by vertex alpha. No per-mesh UV surgery, no hand-painted masks.

FX Mesh Generator previewing a Sword Slash in UV Flow mode, surface arrows showing the baked flow axis, with the seven production recipes and the Shape section below.

A sword-slash recipe reshaped live, its UV layout and baked UV flow checked, and the mesh validated before export — 288 triangles, bounds and UV range.

When to use it

• Melee slash arcs and weapon trails
• Beams, lasers and energy strips
• Shockwave rings and ground impact discs
• Shield domes and bubbles
• Tornado and spiral helix trails
• Any Niagara mesh particle that needs flowing UVs and a soft alpha falloff

What it isn’t for

• Don’t use it for hero geometry. These are FX primitives, not sculpted assets.
• Don’t use it where a ribbon renderer is the right answer. Niagara ribbons follow a moving emitter; these are static meshes.

Opening the tool

1. Open the EQLabs Hub and search for fx mesh or slash (or browse to Art → VFX).
2. Click the tool card.
3. Pick a production recipe, look at the preview, then adjust.

The panel runs top to bottom in eight numbered sections. A Workspace toggle hides the advanced ones — Advanced (shape edit, modifiers, pivot) — so the default view stays manageable.

1. Mesh & Recipe

Eight mesh families:

Slash · Beam · Ring · Disc · Dome · Half Dome · Helix · Cross Helix

And seven production recipes — a type plus tuned defaults plus recommended UV, alpha and pivot settings:

Recipe	Produces
Sword Slash	A melee arc
Beam Strip	A straight energy beam
Shockwave Ring	An expanding ring
Impact Disc	A ground impact plane
Shield Dome	A protective dome
Tornado Helix	A spiralling column
Cross Energy Helix	Interwoven helix ribbons

Start from a recipe. Apply Production Defaults sets not just the shape but the UV flow, alpha mode and pivot that suit it — which is most of the knowledge in the tool. Two quality passes are available: Quality Pass (Full) and Quality Pass (Mobile).

2. Shape

Shape parameters are family-gated — each mesh type exposes only what applies, and the panel states plainly which fields the current family ignores:

Ignored by this family: …

Representative controls: Radius, Width, Arc Angle, Start Rotation, Root/Tip Scale, Length, Thickness, Height, Open Angle, Roundness, Turns, Ribbon Width, Inner Radius Ratio, Edge Jitter, Noise Seed.

Two worth calling out:

• Arc Angle. 360 is a closed ring; lower values open it into a broken ring.
• Broken Amount. Randomly drops ring columns using the seed, for shattered shockwaves.

2b. Shape Edit (3ds-Max style)

An optional modifier stack for people who think in Max terms. See Modifiers.

3. UV Flow

Where the flow direction is baked.

Control	Notes
Flow Direction	Auto, V Forward/Reverse, U Forward/Reverse, From/To Center, Circular CW/CCW
Recommended UV for this type	What the family expects
Flip current direction	Reverses it
Tiling U / V, Bias U / V, Flip U / V	UV transform, baked

Unreal samples V top-down. Reverse and Flip are BAKED into the mesh UVs — the viewport arrows follow the mesh’s real UV axes, so trust the arrows, not your mental model of which way V runs.

That sentence saves the most time of anything in this tool. Flow direction bugs are almost always someone reasoning about V instead of reading the arrows.

A shield dome recipe under the UV checker, with its alpha preview.

Preview-only flow controls

A clearly separated group that is never written to the mesh:

Control	Purpose
Flow Offset	Slides the preview texture along the flow axis. 1.0 wraps to the same frame — use 0.25/0.5 to check direction
Animate flow preview	Animates it
UV cycles per second	Animation rate

4. Vertex Alpha

The mask, baked into vertex alpha.

Alpha modes include Along U/V, Center Out, Edge Fade, Tip Fade, Flow V, Width U, Center Hole, Root Fade, Corner Fade, Radial variants — and twelve alpha presets:

Flow In · Flow Out · Soft Tip · Soft Edge · All Border · Geometry Border · Center Core · Center Hole · Corner Fade · Noisy Dissolve · Energy Stripes · Reset

Shaping controls: Softness, Power, Range Start/End, Offset, Contrast, Min/Max Alpha, Edge Width U/V, Noise Strength/Scale, Stripe Count/Softness, Invert, Symmetry U/V.

Some alpha modes need interior samples, and the tool says so: “This alpha mode needs interior samples: building with N × M segments.” Segment count rises to serve the mask — expect a heavier mesh.

RGB Packing

Optionally packs the mask into RGB for shaders that read colour: White, Alpha→RGB, Invert Alpha→RGB, Alpha→R/G/B.

RGB is pre-linearised so the saved bytes match; alpha is stored linear. This is the correctness detail that stops a packed mask reading differently from the alpha it was packed from — see the suite’s notes on vertex-colour sRGB behaviour.

5. Modifiers & Shell

An optional stack, family-gated: “Simple stack (family-gated: disabled ones are ignored)”.

Order is fixed and Max-like:

Bend → Twist → Taper → FFD → Noise

with Unreal axes throughout.

Modifier	Controls
Bend	Angle, Axis, Plane, Bias
Twist	Angle, Axis, Direction, Mode (Centered/Bottom→Top/Top→Bottom), Bias
Taper	Amount, Axis, Bias, Direction
FFD	Mode (Box/Cyl), Points (2/3/4), Axis, Strength, per-point Scale/Height
Noise	Scale, per-axis Strength, Seed, Fractal

Per-family modifier profiles

Each family gets a profile explaining which modifiers help and why the disabled ones are disabled — the tool argues its case rather than greying things out silently:

Family	Guidance
Slash	Twist disabled — “twist over-kinks a slash arc.” Taper direction matters a lot
Beam	Twist disabled — “a twisted beam reads as a kinked ribbon.” Taper, Bend, light Noise
Ring	Twist and Taper excluded — “circular topology already carries rotation.” Use Circular Bend + Noise
Disc	Prefer centre-to-edge Bend and subtle Noise. “Rotate via texture / UV flow instead”
Dome	Accepts light twist, taper, noise — keep values low or the silhouette breaks
Half Dome	Twist excluded — “twist skews the left/right silhouette”

Shell / output topology

Control	Notes
Shell Thickness	Gives the surface depth
Shell Axis, Shell Mode	Center, Outer, Inner
Flip Normals, Double-Sided Geometry	Sidedness
Normals, MikkT Tangents	Whether to generate them

6. Pivot & Axis

Control	Notes
Pivot Anchor	Keep Generated Origin, Bounds Center/Bottom/Top, Custom Offset Only
Pivot Offset, Pivot Rotation (P/Y/R)	Fine placement
Centre vertices after build	Re-centres geometry
Recommended pivot for this type	What the family expects

Pivot placement decides how the mesh behaves as a Niagara particle. A slash wants its pivot at the hilt; a shockwave ring wants it at the centre.

7. Preview & Helpers

Preview modes: Solid Tint, UV Checker, Vertex Alpha, UV Checker + Alpha, Vertex RGB, UV Flow.

Viewport helpers: UV surface flow arrows · generation flow guide · U/V basis (orange/green) · mesh wire · bounds · face orientation (green front / orange back) · pivot gizmo · generated axis gizmo · labels · helper scale · max surface arrows.

Face orientation is worth leaving on. Single-sided FX meshes facing away from camera are invisible, and green/orange tells you instantly.

A tornado helix recipe previewed with its UV flow and alpha before it is validated and saved.

Preview LOD

Off · Auto · Performance

Reduces segments for the preview only. Save always rebuilds full quality. The preview being cheap never costs you output fidelity — and the status line marks preview-LOD builds so the numbers are not mistaken for final.

8. Validate & Save

Control	Notes
Output Path	Long package path, e.g. /Game/EQLabs/FXMesh/Generated
Export Preset	See below
Overwrite existing asset	Guard
Validate	Runs budget validation without saving
Save Static Mesh	Writes the asset
Batch: all 7 recipes	Generates and saves the whole recipe pack
Place in Level	Spawns an actor referencing the last saved mesh — undoable

Export presets

Preset	Configuration
Niagara Mesh Particle	Single-sided, no tangents, RGB White, centre pivot
Static Mesh Trail	Adds normals/tangents, bounds-centre pivot
Two Sided	Double-sided

The mesh is always saved material-free. The preview material is a debug aid, not an export — assign your real FX material downstream.

Reports and status

FX Mesh Generator after Batch: all seven recipes saved, with a per-mesh validation report listing geometry, UV, vertex-alpha range and mobile triangle budget for each, plus CSV and HTML export buttons.

The status line reports measured facts after every build:

SwordSlash: 812 verts, 1420 tris, 180x40x6 cm — build 12 ms, preview mesh 4 ms

Validation produces a report with error/warning counts, and Copy report (CSV) / Save report (HTML).

Place in Level requires a saved mesh — it references the asset, and says “Save the mesh first” rather than placing a preview.

Tips and gotchas

• Start from a recipe. The defaults encode which UV flow, alpha and pivot suit each family.
• Trust the viewport arrows for flow direction, not reasoning about V. Flip and Reverse are baked.
• Flow Offset, animation and Preview LOD never reach the mesh. They are preview-only by design.
• Some alpha modes force higher segment counts to get interior samples — the tool warns, and the mesh gets heavier.
• Disabled modifiers are ignored, not clamped, and each family explains why.
• Saved meshes are material-free. An unassigned-looking result in the level is expected.
• Leave face-orientation helpers on for single-sided output.
• Batch: all 7 recipes is the fastest way to get a starter FX mesh library.
• Validate before saving in bulk. Budget failures are cheaper to find before you write seven assets.

Full walkthrough

The full workflow, start to finish.

Related tools

• Niagara Profiler — profile the systems these meshes feed
• Niagara FX Library — browse and reuse FX systems
• Flipbook Maker — the texture side of an FX asset
• Smear FX — the other motion-exaggeration mesh generator