Regardless Niagara or Cascade, dynamic parameters for particles are passed to pixel shaders from vertex shaders via InterpolantsVSToPS.

It can cause a precision error on some materials, for example like the following image.
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If we set the material's dynamic parameter to 1.0, you can see the particles looks noisy incoIrrectly.
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Because its interpolator output values slightly different from 1.0 to each pixels. As a results, frac(dynamicparameter) of some pixels returns 0.9999 because the dynamicparamter of the pixel is less than 1.0.
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I tried adding "nointerpolation" to DynamicParameters' interpolators as a test on 4.23 and it seemed to fix this issue.
(Shelved CL:7683250)

Steps to Reproduce
  1. Download the attached project and open it.
  2. You can see two noisy particles in the scene you opened.

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ComponentRendering - Niagara
Affects Versions4.214.224.23
Target Fix4.25
Fix Commit10086872
Main Commit11123615
CreatedAug 1, 2019
ResolvedNov 8, 2019
UpdatedJan 28, 2020