A model-free URP welding VFX with a travelling arc, progressive weld bead, cooling metal, sparks, smoke and an editable baked path.Present a focused arc-welding visual without a torch or character model. Welding & Cooling Seam VFX URP shows a bright arc travelling along a saved path, progressively depositing a hot bead that cools into metal, supported by ballistic sparks and soft smoke. The effect hierarchy and completed seam are saved in the Editor for convenient inspection before Play.The included All Welding Presets scene shows all three connected variants side by side. Use the supplied prefabs and presets, or edit the local Bezier-style path and bake it into a new persistent mesh asset from the custom inspector. Drive the effect with BeginWeld, StopWeld, ResetWeld, SetProgress and SetCoolingAge. BeginWeld restarts from progress zero; StopWeld preserves the deposited section while heat and existing particles decay.This package provides decorative VFX only. It does not implement welding physics, manufacturing simulation, collision, damage, mesh fusion, audio or a generic runtime spline system. A four-page PDF manual covers setup, path baking, runtime integration, performance and limitations.Pre-submission review note: the included provenance notice records an MIT-licensed behavioral research reference whose code and LeanTween are not distributed. Final human authorship, ownership, original-value and marketplace review remains required before submission.Target: Unity 6000.0.30f1, Universal Render Pipeline 17.0.3, linear color. Built-in Render Pipeline and HDRP are not supported.Includes three preset prefabs, saved seam meshes, runtime controller and path components, custom non-overwriting mesh baker, purpose-built URP shaders, materials, particles, light, focused demo scene, three-preset gallery scene and four-page PDF manual.35-second 1920 x 1080, 30 fps Unity capture. Official Publishing Tools: 34/34 checks passed with no warnings or failures. Clean-project Play: 350 frames with finite visible Direct3D 11 GPU output. Twenty-one private API/path/mesh checks passed. These checks are not certification for every device or graphics API.No VFX Graph, Shader Graph, external textures, audio or paid plug-ins are required at runtime. Windows Direct3D 11 is the reviewed graphics path; mobile, VR, consoles, WebGL and other APIs are not certified.AI was used during code refactoring and scene preparation.
