I've started playing with Houdini and I'm enjoying it a lot. It is really a refreshing software, a total new paradigm for modelling !
I'm trying to reproduce an old scene of red blood cells inside a vein. I've setup the camera and lights (importing an alembic files without any problem). Camera and lights seems to work. I've added also a bit of noise (and I will have to understand how to make it pulse but I was thinking about using a sin($F) applied to a scale in some way or another). Now I need to put the red cells and make it interact with the sweep. So what I was thinking that probably the best thing will be to create one red blood cell (low poly) and use it with vellum (in order to make it bounce and deform). I need to put a lot of them so I don't know if this is a good idea…
Any suggestion appreciated.
There's the file. I hope to have post in the right place.

You should be able to do a lot of them in vellum. I'm not sure how many you mean by “A lot” but as long as you don't ram out your gpu you should be good.

Update !
1) I've succeeded in creating the “heart beat”
2) Created the particle system and instanced (for now spheres) it seems I can really create a lot of them without too much problems (or at least the number that I need)
A few problem remains and actually
1) I do not understand why the balls seems to go “inside” the sweep even if they act correctly
2) I can succeed in creating a vellum for one ball but not for the instanced copies (not because of memory, just one simulation exclude the other)
3) Probably I can also use the balls as is without using vellum but then I will need to create some kind of noise to make them different and no idea how to do it
4) finally use a low cell (already created) instead of the balls.
Sorry for the easy questions, I'm just starting. Any help appreciated

Vellum crashes around 9 millions tets in H17. Do not play more than this amount.