Apprentice 10.0.249.5 (Mac & Windows)

I've been having trouble with the Pyro walkthrough ignoring my cached files. If I close and re-open any project, it insists on re-cooking everything.

I've tried this under both Mac and Windows and get the same result. AFAIK I'm doing everything right: Rendering the correct frame range, saving with the ${OP}_$F expression (and tried manual naming too, i.e. lores_$F), and I definitely have Load From Disk checked.

I've spent 2 days trying to fathom this out, re-checking both the docs and even the tutorial video on Pyro FX, and can't see where I'm going wrong.

Am I missing something?

Cheers,
Ad

Not sure offhand but a suggestion - make sure you're only displaying the lores and you're at object level when displaying. If you happen to have a DOP selected, for example, the DOPnet cooks.

Also, keep in mind that if you're talking about cached *hi-res files*, you should expect some cook time loading them up, even though it's already been ‘cooked’, it's actually got some significant populating to do. It's still a lot less than the original cook, though.

Cheers,

J.C.

Try going into the uprespyro Node and click on the Display Render (Blue) in the pyrofields node.

Thanks guys,

Your suggestion regarding recooking seems to be spot on J.C., and I've gotten around it to some extent by reducing the complexity of the sim (particularly the lowres resolution). Certainly can't complain anyway as the results are quite stunning with a little graft.

JColdrick
Not sure offhand but a suggestion - make sure you're only displaying the lores and you're at object level when displaying. If you happen to have a DOP selected, for example, the DOPnet cooks.

Also, keep in mind that if you're talking about cached *hi-res files*, you should expect some cook time loading them up, even though it's already been ‘cooked’, it's actually got some significant populating to do. It's still a lot less than the original cook, though.

Cheers,

J.C.

the re-cooking aspect is soooo frustrating. for example, in the pyro movie
http://www.sidefx.com/index.php?option=com_content&task=view&id=1284&Itemid=305 [sidefx.com]

after he caches the simulation on the uprez and lowrez, he mentions that we should set the sphere to not simulate also. (mark 9min42sec)

what did he do there to ‘tell this not to simulate’?

for mac users, i've discovered that we cannot name our sim caches as he did in the pyro video.
xxx.bgeo.gz
no gz for us!
also, we cannot just click the nav button, find a folder and include variables in the name. houdini 10 mac will force a .dxf format and will not allow variables. you must TYPE IN THE NAME in houdini including the folder structure and variables.

so, if you make a folder for your project that is nested like this for example:
(homefolder)~/documents/houdini_projects/pyrotests/caches/
then this typed into the ‘geometry file’ field will work for caches

$HIP/caches/${OS}_UPrez_$F.bgeo

and place them into the caches folder. this is VERY UN-MAC-LIKE, but it works. notice, NO .gz here.

this issue is known: bug, ID# 33661

summary for all you houdini gurus:

please help the rookies with caches and re-cooking.

for a houdini rookie, the cooking process is bad enough with out the extremely TOUCHY and complex series of dependancies that will result in re-cooking.

simulations are such a big part of the draw to houdini but are also one of the main frustrations to new users. it it VERY difficult to tweak a result when the app wants to re-cook. it is very difficult to know what setting is causing the re-cook. it is very difficult to know what kinds of changes are allowed that will not cause a re-cook. aaarrrrrggghhh.

does anyone know of a tutorial that specifically addresses caches for sims?

the re-cooking aspect is soooo frustrating. for example, in the pyro movie
http://www.sidefx.com/index.php?option=com_content&task=view&id=1284&Itemid=305 [sidefx.com]

after he caches the simulation on the uprez and lowrez, he mentions that we should set the sphere to not simulate also. (mark 9min42sec)

what did he do there to ‘tell this not to simulate’?

What he meant is to set the display flag on the sphere1 SOP instead of the dopimport1 SOP inside the sphere_object1 Object. This way, you're not getting the sphere geometry from the fluid sim. Alternatively, you can turn off the display of the sphere_object1 Object.

for mac users, i've discovered that we cannot name our sim caches as he did in the pyro video.
xxx.bgeo.gz
no gz for us!
also, we cannot just click the nav button, find a folder and include variables in the name. houdini 10 mac will force a .dxf format and will not allow variables. you must TYPE IN THE NAME in houdini including the folder structure and variables.

so, if you make a folder for your project that is nested like this for example:
(homefolder)~/documents/houdini_projects/pyrotests/caches/
then this typed into the ‘geometry file’ field will work for caches

$HIP/caches/${OS}_UPrez_$F.bgeo

and place them into the caches folder. this is VERY UN-MAC-LIKE, but it works. notice, NO .gz here.

this issue is known: bug, ID# 33661

I have a mac at home and the native mac file browser doesn't really work well for Houdini. There is an environment variable to only use Houdini's file browser (which I think should be the default, IMHO) but you have to set it up through the houdini.env file.

I don't remember if the houdini.env file is created in the $HOME/houdinix.x directory automatically but you can copy & paste the following into a file named “houdini.env” and make sure it's in the $HOME/houdinix.x directory:
#
# Houdini Environment Settings
#
# The contents of this file are read into the environment
# at startup. They will override any existing entries in
# the environment.
#
# The syntax is one entry per line as follows:
# VAR = VALUE
#
# Values may be quoted
# VAR = “VALUE”
#
# Values may be empty
# VAR =
#

# Example:
#
# HOUDINI_NO_SPLASH = 1

HOUDINI_USE_NATIVE_FILE_CHOOSER = 0


Here's what the environment variable is used for:
HOUDINI_USE_NATIVE_FILE_CHOOSER
This variable controls whether Houdini will use the file chooser dilaogs
provided by the operating system. By default Houdini will try to use them,
but only on platforms on which Houdini supports native file choosers. If
this variable is set to 0, Houdini will use own file browser dialogs. There
are three levels that this variable can specify:
0 - only Houdini's own file choosers are used
1 - Houdini and MPlay will use native file choosers for their File > Open…
items in their main menus. For any other file browsing, Houdini will use
own file choosers. This is the default behaviour.
2 - if possible, Houdini will use native file choosers for browsing any
file.

summary for all you houdini gurus:

please help the rookies with caches and re-cooking.

for a houdini rookie, the cooking process is bad enough with out the extremely TOUCHY and complex series of dependancies that will result in re-cooking.

simulations are such a big part of the draw to houdini but are also one of the main frustrations to new users. it it VERY difficult to tweak a result when the app wants to re-cook. it is very difficult to know what setting is causing the re-cook. it is very difficult to know what kinds of changes are allowed that will not cause a re-cook. aaarrrrrggghhh.

does anyone know of a tutorial that specifically addresses caches for sims?

To prevent re-cooking when adjusting parameters, either go to Frame 1 (or the start frame of the simulation) or turn off “Enable Automatic Resimulation” under the Simulation tab of the DOP Network Object.

If you turn off “Enable Automatic Resimulation”, the Brain icon in the bottom right corner will become pink when you make a change which means the simulation is out of date & you have to re-cook the simulation. You can either go to Frame 1 or stay on the current frame, RMB on the icon & select the DOP Network that needs a re-cook.

Alternatively, you can set the cooking mode from “Auto Update” to “Never”. This way, you can adjust the parameters you want, go back to Frame 1, set the cooking mode to “Auto Update” then hit play.

Every parameter change in a simulation will cause a cook because the current result depends on what happened previously. For example, if you change a force value, the simulation will have to compute the change from the start.

It is frustrating but it's getting used to a work flow.

Cheers!
steven

okay, i just watched, and followed the above ref pyro movie again. i clicked only on what he did and still houdini tried to re-cook even after the uprez and lowrez were cached. oh, and the sphere was un-simulated.

Every parameter change in a simulation will cause a cook because the current result depends on what happened previously. For example, if you change a force value, the simulation will have to compute the change from the start.

lowrez pyro render (shows just fine)
dop switch set now to uprez
obj level
highrez pyro node render (shows nothing)
set sphere to not sim
followed movie and set visuals as he did
still high rez shows nothing. ARRRGH
set dop switch back to low rez
RE-COOK BEGINS AGAIN!
sigh. didn't i just cache those above and set to read from disk?!
!@#$!@#%!@#$!

(i just have to keep reminding my self of that the superiority of houdini warrants this frustration!)

i had a look at the cache files created, 1 for each frame, and they are all 4k files with no visible data in them.

sigh.

i give up 4 today.

with professional level 3d work for 11 years under my belt and 3d hobbiest experience going back to 92'… i would think this would be a little easier of a transition. (self indulgent pity paragraph)

i'll start dragging the houdini cement block up the learning curve again tomorrow.

thank you for your responses. really. appreciated.

The completely unnecessary dopimport SOPs that the shelf tools litter around the place are most often the culprit of recooking. The current cache-to-disk workflow is definitely not a straight-forward setup… it takes being quite familiar with Houdini to recognize which is causing re-cooking, and then playing hopscotch with display/render flags before you can solidly read in a cached simulation. :?

here is what i noticed last night.

in UPREZ the link to the LOWREZ is only for a single frame!


i tried to change the frame number to a sequ variable, but i keeps reverting back. the macintosh version will not put out the cache as a singe file as other versions of houdini will. so, the uprez is not getting the lowrez info.

jason_iversen
The completely unnecessary dopimport SOPs that the shelf tools litter around the place are most often the culprit of recooking. The current cache-to-disk workflow is definitely not a straight-forward setup… it takes being quite familiar with Houdini to recognize which is causing re-cooking, and then playing hopscotch with display/render flags before you can solidly read in a cached simulation. :?

if you have a moment to role play a bit, and also if you have access to a mac, please walk through the intro to pyro movie as if you were a rookie.

maybe a screenshot of some changes you would suggest or … anything really…

i would simply like to know how to predict the behavior of the most expensive aspect of that demo, the simulations. i cannot even begin to play with the turbulance, fuel, or cooling rate settings without control over these darn extended wait times. :evil:

one can hardly progress in houdini, if it is littered with un-intuitive 20min-wait land-mines. one blind click and POOF! 20 minutes are gone that you'll never get back. hahaha