File to POP network?

[Wolf-S]

Hi,

I have saved particles into a geometry *.bgeo file.

Now when I load it using File node, I want to make modifications to these particles.

Is it possible to fetch the loaded particles into a POP network? (akin to the Fetch node?)

Edited February 16, 2012 by Wolf-S

[gaurav]

Hi,

I have saved particles into a geometry *.bgeo file.

Now when I load it using File node, I want to make modifications to these particles.

Is it possible to fetch the loaded particles into a POP network? (akin to the Fetch node?)

Afaik its not possible that way. Some one please correct me if i am wrong.

You have to send the written out points again in a pop sim to source new points.

But if your modification is only limited to the input geometries of a pop-network,

you might want to take a look at the popmerge sop node.

Its handy at times if all you want is to modify your input streams going in a pop-network.

Without having to duplicate or put down extra popnet to have different results.

Cheers,

[anim]

it depends on type of changes you want to make

modifications can be made in SOPs

what I usually do is cache particles with v, life and id attributes, then I have a possibility to recreate other attributes like pscale, Cd Alpha or other based for example on life or speed with some variance in SOPs in realtime without any resimulation

if you want to change whole behavior of the particles why not going back to original POPnet and tweak that?

on the other hand you have the ability to set initial state on POP node which can be based on saved bgeo

or you can source points from any file SOP by source POP so use them for something in the simulation (like for goals)

so actually you have all possible options it just depends which one suits your needs best

[Macha]

Hey Ed, here are a few tricks to consider. Depending on the nature of your particlesim you may be able to split your effect into sequential or parallel popnets. For example, if you were hampered by a need for excessive oversampling (high speeds for example) you could first set a "seed-pop" at high oversamples and append an effects pop afterwards. Or if you were to split particles you could create a first pop with infinite life particles, blast them away afterwards and use them in another pop.

This does add management complexities into your network, so it's often not worth the effort, but sometimes it is and it may even be the only way on occasions.

Edited February 16, 2012 by Macha

[Wolf-S]

Thanks for helpful replies.

I needed to access particles for the previous frame because I had a custom inline cpp SOP that acted on points/particles.

Abandoning inline cpp in favor of pure cpp compiled with hcustom did the trick. I created a POP, transferred some code to the cook function and it worked without any File save-load nodes. I hadn't realized POP is always being updated (cooked) for the necessary amount of frames.

Edited February 28, 2012 by Wolf-S