Nif Particle Emitters for FX

[Ashnal]

So I've got no idea when it comes to Nifs, but recently I've been wanting to change some particle effects. The DetectLifeFX.

 

I've been looking through the attached Nif file at the particles, and I'm wondering where the overall alpha of the particles are set, the size of the particles, and their spawn rate. I would have thought these things would be obvious .... but I can't find them. Using the latest Nifskope for FO4.

[Ashnal]

So .... I actually found these after a few hours of tinkering in Nifskope.

 

For future reference .... I'll list my findings here. They're all specifically for particle emitters attached to effect shaders, such as DetectLifeFX.

 

First, particle spawn rate:

Starting at the NiParticleSystem Node, there are child nodes of NiPSysActiveCtlr. For all the particles I looked at, there are 3 of those, one for each of the X Y and X axes. Under that is NiPSysEmitterCtlr, and under that is NiPSysUpdateCtlr.

Underneath NiPSysUpdateCtlr there is a child node NiFloatInterpolator, this is what we are interested in. The value contained here controls how fast particles are spawn, with the higher, the faster particles spawn.

 

Second, particle size:

Find the child node of NiParticleSystem, NiPSysMeshEmitter. Within NiPSysMeshEmitter "Initial Radius" will control the initial size particles spawn at. This can be further modified by the "Radius Variation" field. It can be scaled for the duration of the particle's lifetime by another child node of NiParticleSystem, NiPSysScaleModifier. The array of floats in NiPSysScaleModifier represent a timeline of scale changes over the particle's lifetime.

 

Third, alpha and color:

Alpha, as well as color, at least for the particles I was working with, was set in another chld node of NiParticleSystem, BSEffectShaderProperty. Within there is a value called "Emmisive Color" which controls the color of the particle and alpha. The particular nifs I was working with were already set to use a greyscale texture that would be recolored to the color specified here, and I didn't really look at any other circumstances.