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Set Shader Uniform

Writes one number inside an object's shader graph, so a trigger, a timer or a counter can drive how the material looks — a panel that heats up when you stand near it, a glow that pulses when something is picked up, dissolve that runs on a countdown.

Output: effect (wire into an Object Selector)

Parameters

Parameter Default Meaning
uniform (empty) the name of the value to write, as shown in the Shader editor
value 0 the number to write (usually wired, not typed)

Finding the uniform name

A shader graph's numbers, colours and vectors each compile to a named value. To find the name:

  1. open the Shader editor on the object,
  2. click the node whose parameter you want to drive (a Float node, say),
  3. read the uniforms list in the ⓘ info pane on the right — it shows names like u_rgh_value,
  4. paste that into this node's uniform field.

Only numbers can be driven this way. Colours and vectors are not yet supported, so to animate a colour, drive a number and turn it into a colour inside the graph — a Gradient or a Mix between two colours does this well, and is usually nicer to author anyway.

How it behaves

Writing a uniform does not recompile the shader, so this is cheap enough to run every frame.

Each peer writes the value locally, and no message is sent. It does not need one: the value arrives through the flow graph, which is already deterministic and replicated, so every peer computes the same number and writes the same result. This is the same approach Set Color takes.

If the object has no shader graph, or the name does not match anything in it, the node does nothing — it will not error or break the material.

Practical example

A crystal that glows brighter as you approach:

  1. Give the crystal a shader graph: Float (0) → Surface emissive, and a Colour → Surface albedo.
  2. Select the Float node and copy its uniform name from the ⓘ pane.
  3. In the crystal's flow: Proximity (radius 4) → Map Range (0–1 in, 3–0 out) → Set Shader Uniform (paste the name) → Object Selector picking the crystal.
  4. Walk towards it. The glow rises as you close in, on every peer's screen at once.

Swap Proximity for a Timer or a Counter and the same wiring gives you a timed dissolve or a charge-up that steps each time something happens.