So, this isn't so much of a "tech support" question, as it is just trying to discuss different methods of accomplishing common results. In this instance, the issue is particles in the UI.

I'm mostly interested in the Unity case

Basically I've come up with the following solutions:

1) Bake the effect into a multi-frame texture and animate them
Pros: Can use existing tools (like After Effects) and can use as much detail in a single effect as you like
Cons: Requires more texture memory. Limited diversity (a lot of the benefits of particles thrown out the window). Large, alpha blended texture not great for performance.
2) Storyboard the effect (Particles are UIElements).
Pros: Resolution independent (potentially). Can view results in Blend.
Cons: Setting up storyboards is a very tedious process, even for simple effects. Low diversity (can apply multiple out-of-phase storyboards, though it would be even harder to set up). Not scalable (requires many UIElement).
Q: WPF would not, but could we potentially tweak blend modes? Additive blending being quite important
3) Custom control for particle emission
Pros: Single implementation per emitter shape and force mode. Less tedious than manual storyboard creation
Cons: Does not exist, so major engineering drain. Don't really have custom control options in Noesis/Unity. Still has resource issue from so many UIElements
4) Create effects layer bitmap objects, render particle effects to texture, set image brush to use render texture
Pros: basically the same capabilities as UI particles in the Unity GUI libraries
Cons: More difficult to setup. Either limited distance/range, or requires a large, sparsely populated, alpha-blended image brush (performance issue). Can not be viewed in Blend (can use proxy image though).
5) Draw effects over UI
Pros: pretty straight forward. Good performance
Cons: only can draw on top of UI. Not easy to attach an effect to a UIElement (requires programmer time to create layer to translate from UIElement render transform to Unity world transform).

My goal is to try and come up with a golden path such that other can know what the best way to go would be. If you have suggestions, or even suggestions for paths to attempt, please post it below.

I think that each proposed solution can be the best in different scenarios. Do you have a screenshot or video showing the effect you want to achieve? It will help to know what you have in mind.

As I stated at the beginning, it isn't really a support is, but rather an open discussion. Mostly I'd like to collate different solutions to common problems without canonical solutions. Particles is one, as they are in fairly common use in game UIs but there is no direct support in NoesisGUI (or any XAML flavor I know of. Silverlight had a thirdparty library built on WritableBitmap, though). The more we pool knowledge, the better our productivity will be in the long run... or so I hope.

Have a a link for that thirdparty library? I would like to investigate it.

At first, I see a big trouble here related to particles. There is no additive blending in WPF. As It has been requested several times we are going to implement it as an extension.

To me 1) seems to be easiest option. If performance is not very bad (should not if the particles are small) I would choose that.

It would be ideal having samples for each option.

Sorry for bringing back such an old thread, but i'm wondering how people do particle effects in Noesis Gui? From the suggested ways of doing particle systems i am mostly interested in showing the real particles from unity so it's not static and you have all the flexibility to create awesome effects. Is this possible in the current version of noesis? Adding effects between ui elements for example. Adding the effects on top of the ui might not be suitable in some cases.

You can render to texture in Unity and use that texture inside NoesisGUI. We are also working on Effects, once that feature is implemented you will be able to use custom shaders inside Noesis.