How to use the Three.js Weather Effects agent skill

What the skill makes the agent do

Once installed, the agent follows the skill's guidance when you ask it to add weather to a Three.js scene. The skill covers keeping rain inside the camera's view, building a storm by intensifying the rain system rather than adding a second one, lightning on its own light with thunder timed by distance, snow that blows up into blizzards and settles on the ground, wet ground with puddles and splashes, and looping ambient audio without an audible seam.

The skill mainly guides how the code is written. It does not render anything itself, so you still need a Three.js project for the agent to work in.

• Rain volume anchored in front of the camera so drops are visible
• Storm built from the rain state with faster fall and more slant
• Lightning flashes with thunder delayed according to distance
• Blizzard cycles of calm, build, blow and ease
• Snow that accumulates on the ground while it falls
• Wet ground, puddles and splash rings
• Looping weather ambience with a cross-fade at the loop point

How to install the threejs-weather skill

Download the ZIP for the skill from this page. Unzip it into your personal skills folder, ~/.claude/skills/, so the skill is available in every project. To limit it to one project, unzip it into that project's .claude/skills/ folder instead.

If you use the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.

• Personal install: unzip into ~/.claude/skills/
• Project install: unzip into the project's .claude/skills/ folder
• Claude apps: upload under Settings → Capabilities → Skills

How to trigger the skill with natural requests

You do not need a special command. Name the skill in your request, or describe the weather you want and mention Three.js. The skill's own description covers scene atmosphere, seasonal states, hero backdrops and any world where clear, rain, storm and snow should be a control the viewer can turn.

Be specific about the state and where it should appear. The demo prompt in the package asks for drops anchored inside the frustum rather than scattered over the world, which is the detail the skill is built to handle.

• Name it directly: use the threejs-weather skill to add rain and a storm to this scene
• Ask for a control: add clear, rain, storm and snow states that the viewer can switch between
• Ask for behaviour: make the snow blow into a blizzard after a while and leave the ground whiter over time

Examples of what the agent builds

The package includes a demo called Four Weathers Over One Field. It describes one landscape with four states on a single control: clear, rain, storm and snow. The storm is visibly the rain state pushed harder, with more drops, faster fall and further slant. Lightning strikes on its own schedule, and snow arrives calm, blows up into a blizzard and eases off again.

The skill's guidance also covers small technical choices that affect how the result behaves. For example, it recommends setting a draw range to thin the drops instead of reallocating buffers when weather changes, which avoids a hitch while the viewer is watching.

What it needs and safety notes

You need Three.js and a web project that can run browser code. The listing does not mention API keys or accounts, and the skill's files do not use them.

The skill does not run scripts and does not use the network, according to its listing. It is a set of written instructions for the agent, so review the code the agent produces as you would any code before you deploy it.

The skill is not suited to every project. Simple static pages where a CSS or video background would do will pay a real rendering cost for this effect. It also does not show live forecast data.

• Requires Three.js and a browser-capable web project
• No API keys or accounts mentioned
• Runs scripts: no
• Uses network: no

Tips for getting a good result

Check the effect in the places where the skill says it usually fails. The guidance warns that the particles can miss the camera entirely, and that a rain system can look correct yet never move because the attribute holds a copy of the array you kept.

Test the state changes as well as the steady states. The skill suggests entering snow from clear several times to confirm it always starts calm, and leaving snow on for a couple of minutes to see the ground whiten.

• Watch a single raindrop from spawn to ground to confirm it is inside the view
• Leave snow running for two minutes and check that the ground is visibly whiter
• Stand in a storm and confirm strikes come from different sides
• Profile with the storm running, since relighting is usually the expensive part