Issues with niagara scratch pad module : "map for" node not woking with CPUSim and "Custom HLSL" array undeclared

Development Asset Creation FX
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Hello, I have 2 issues with niagara scratch pad module.

First :
If if I set the emiter Sim Target to “CPUSim” the “map for” node in scrath pad modules doesn’t work, but if I set the emiter Sim Target to “GPUCompute Sim” it does.
MapFor
I have no error, it just doesn’t loop.
I need my particles to collide with some colliders in my scene so I need to use CPU Sim…

Second :
Since map for didn’t worked, I tryied to use the “Custom Hlsl” to loop my array.
But if I link an array (like a float or vector array) to the “Custom Hlsl” node I have an error that say that the variable isn’t declared.

HlslArray
HlslArray799×465 47.6 KB

Is it not possible to pass arrays to the “Custom Hlsl” node, or am I doing it wrong?

Does someone have a solution/explaination to either of those issues?
Thanks.

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Loops are not yet supported on cpu simulations.

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3

hi, could you please show some examples of how to use the MAP FOR node in Niagara ScratchPad? Thank you.

4

Here is an example setting array elements in a loop

image
image1929×634 128 KB

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@Michael.Galetzka , could u please show an example of adding element onto the totally empty array. Is it possible? And if it is not very hard to u, one example with HLSL … Thank u very much :blush::pray:

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@Michael.Galetzka, Is there a way to get the Map For node to work for a System or Emitter Module? It seems to only run through the loop once in those cases.

I did get it to work for Particle Spawn and Particle Update thanks to your help.

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No, the map for node does NOT work in cpu scripts. Both emitter and systems scripts always run on the cpu.

The map for node only works correctly in particle spawn/update scripts or sim stages in a gpu emitter.

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