New to Houdini but making strides.

Where's the typical place to keep “internal” / private parameters and constants in a network? For now I've just been creating a Null and editing the parameter interface on that to create stuff I want to be able to tweak without exposing it to the artist.

Is that OK, or is there a more usual place? (I s'pose I'm asking because it seems strange to have this little Null floating there, not connected to anything - but at least I can keep all my tweaky stuff in one place)

Hehehe - yep, I've come from a video / programming background so starting at 1 grates horribly. Knowing it comes from traditional animation makes sense though. Instinctively, if I want (say) particles to emit on the first frame, I want to type $SF==0 into the box, not $SF==1. Knowing that there *is* a reason behind it helps me adjust though

I wonder whether H copes with negative frame numbers… might have to test… but starting things at frame 1 means any pre-roll created by, say, jittering particle birth time backwards still keeps things in the positive domain…

OK, I'm now overthinking this and wasting all your bandwidth.

Thanks!

I can't get my head round it. There's nothing to stop you changing it to 0, but I just don't get why SideFX (and a couple of other 3D package developers) think 1 is a better frame number to start on.

Timecodes start at zero; the moment I start dropping stuff into an NLE or a comp somewhere else, everything starts at zero again.

I'm not complaining (more of a kinda childish winge) - I just want to understand *why*. Is there some historical reason?

Any thoughts?

I made a quick animation to test my Houdini–>AE script, and noticed something weird in the particle bokeh. It's very clear around 6 seconds into this, when the particles start to get near the camera:

https://vimeo.com/227242596 [vimeo.com]

The particles have a weird—almost rose-petal-like—bokeh look. I've created a super-simple scene to illustrate the weirdness: just a particle emitter and a camera. When rendered with depth of field and motion blur, the bokeh seems to converge towards a peculiar pattern. Can anyone tell me what's going on? (might need to zoom in on it a bit)



I realise I'm asking a lot of Mantra - the particles are very small (0.02), hence the high Pixel Samples. But it's almost like something isn't being jittered that ought to be.

Any thoughts?

(my wife says I've always had a strange bouquet but I think she means something different)

Hehehe - sorry to wake the thread up again, but this may be the first page people find if they're looking for this sorta thing.

I've written an unbelievably hacky script to get camera/object animations out of Houdini and into AE. It's cludgy, and everything's hardcoded, but it works, and it's simple enough to understand and tweak to your needs:

script: https://gist.github.com/howiemnet/9252ec2fd15c51e4f708c3a535f194fc [gist.github.com]

usage: create a new toolbar button, copy this script into it. Adjust the constants at the start to taste (like, choose the cam/object you want to grab the animation from etc). Run the script. It'll create a text file in your home folder: open it, copy it to the clipboard. Now you can paste it onto a camera (or other 3D layer) in After Effects. Woo… keyframes. Up to you to set up the AE camera (focal length/aperture) the same way as it is in Houdini, mind, but that's just a couple of numbers to copy over.

quick example: landscape/particles in Houdini, distant sky/stars and emitter lensflare in AE:
https://vimeo.com/227242596 [vimeo.com]

jerry7
The most important thing to work together with AE for mothion graphic is import/export object anmiation especially Camera Animation.

I'm an utter Houdini noob, only installed it yesterday. My background was 3DSMax, then Blender. Starting to get my head round things. Just about. (hey look, I made a cube)

But I know one of the first things I'm going to have to try and do if/once I get up to speed (like in 6 months or so - Ha!) is create some sort of camera exporter for After Effects, if I can't find one.

I understand the reaction in this thread - AE does seem to belong in a different tier of visual s/ware to Houdini - but it's the tool some of us are comfortable comping in. And I've got a swathe of AE plugins I'd like to be able to use along with my output from Houdini. Plus it's incredibly fast at some things… Particular's particle systems ain't any where near as industrial strength as Houdini's, but they render lightning fast (yay GPU), and are perfect for certain situations. Especially on short deadlines.

So yep - outputting camera and object animations is pretty important to me, but I'm not as interested in the idea of an AE Houdini Engine; I'm not sure whether the cost/benefit ratio would make it worthwhile.