Description

Sampling a Cascade Mesh Particle's scale always returns XYZ as 1.0

This is a regression from UE4/Release-4.24. 

This does NOT affect Niagara Mesh particles. 

I've attached a Cascade (left example) vs Niagara (right example) comparison of this issue between 4.24 and 4.25

 

Steps to Reproduce
  1. Create and open a project
  2. Create and open a new material
    1. In the graph, add an ObjectScale node
    2. Off of ObjectScale's Scale XYZ output, add a VertexInterpolator node
    3. Connect the VertexInterpolator's output to Base Color
    4. Apply changes
  3. Create and open a new Cascade Particle System
    1. Add a Mesh Data module to the emitter
      1. Optionally, select the Mesh Data module and change the mesh (the default mesh is very tiny)
    2. Select the Mesh Data module and enable Override Material
    3. Select the Required Module, set the Material to your material
    4. Select the Initial Size module, expand Start Size > Distribution > Set Max XYZ to 1, 1, 1 and set Min XYZ to 0, 0, 0
  4. View the system in the Cascade editor or in the level

Result: Mesh particles are always white

Expected Result: Mesh particles should vary in color based on the scale of the particle

Have Comments or More Details?

There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-93127 in the post.

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Won't Fix
ComponentUE - Niagara
Affects Versions4.25
CreatedMay 13, 2020
ResolvedAug 31, 2021
UpdatedSep 19, 2021