Dexter

Hey all,

I want to try and start getting into the Houdini fluid tools. I've been trying to use the Particle Fluids to generate some points coming from some animated geometry which transforms in x and snakes left and right in z, basically like a car driving and swerving, with the fluid emission being the car exhaust emission, hanging in the air with some nice fluid sim-esq movement. Trouble is I am getting nowhere! I'm trying to use the particle fluid emitter in conjunction with the particle fluid object and particle fluid solver. I have an emission working but the movement is akin to that of a normal pop sim, with none of the nice eddies and fluid type movement.

I tried introducing a vector field as I thought maybe I need a vector field to advect my fluid object through to get the desired movement, but I can't get it to visualise let alone introduce the type of movement I'm after.

Any help would be appreciated.

Thanks.

The number

Hello all,

I am a little confused by the options in the object merge sop. Specifically the ‘Transform’ and ‘Transform object’ options. Please see the attached hip file.

This is what I understand the various options to mean:-

None:
Merges the box at its sources sop space position, regardless of any obj level xforms on the source obj.

Into this object:
Takes into account the sources sop level and object level xforms and its own object level xforms and dynamically adjusts to object merge the box at the exact position of the source.

I think I got these ones down. Please correct me if I am wrong. The option which confuses me is ‘into specified object’:-

Into specified object with ‘Transform object’ blank:
Does the same as ‘None’. Grabs the box at the sop level position of the source regardless of obj level xforms on the source.

Into specified object with ‘Transform object’ .
The same as specifying ‘Transform’ as ‘Into this object’.

Into specified object with ‘Transform object’ referencing box3:
This is the one that confuses me. If I use ‘Box_3’ as the ‘transform object’, the object merge seems to ignore any sop space xforms for ‘Box_3’ and then apply the inverse of any ‘Box_3’ obj level xforms. For example if I set ‘Box_3’ ty = 5 at obj level, the object merged box then merges as if it has a -5 xform somewhere. I'm not saying this is incorrect behavior, I'm just confused as to why specifying a ‘Transform object’ means it will apply the inverse of the specified objects obj level transform.

Can anyone shed some light on this? Also if I have stated anything incorrectly I would welcome someone to set me straight.

Many thanks,

Dexter.