Xgen ptex workflow errors to scatter geometry not hair aim to sculpt like hair


#1

Hi cgers

my aim is “xgen scatter using geo say legoblocks,bent into hair like shapes using groom tools”
please see below top part of pic rest is about correcting xgen stuff:
https://www.flickr.com/photos/93465359@N03/48556954822/
additionally using mudbox to paint higher detail ptex maps

trying to open an xgen saved ptex in mudox,
gives error
“mudbox error this ptex contains faces with too big resolution
mudbox cannot import it”

does that,
mean mudbox uses a
different ptex density from the maya xgen save created one. ie 5.0 or 100.0

density mask expression was to create map def:
$a=map(’${DESC}/paintmaps/mask’);#3dpaint,5.0
$a

density mask also tried higher res
$a=map(’${DESC}/paintmaps/mask);#3dpaint,100.0
$a

also if i wanted to load the actual map
say mydensity.ptx creted in mudbox, albeit with a mudbox ptex uvs not mayas
would it have the same ptex resolution as xgen one?


additionally

what would be the expression be to directly load my own mudbox ptex map
tried the following seemed to fail for density mask

$a=map(’${DESC}/paintmaps/mask’);#mydensity.ptx
$a

does this load the texture map in that mask folder straightaway?


found apart answer in old thread
https://forums.cgsociety.org/t/xgen-mask-created-in-mudbox/1631890/4

his delete old xgen ptex and import mudbox ptex and rename to xgen works.

still testing at present


why am i bothering with xgen… so i can hand sculpt and bend like interactive groom, but sculpt
scattered geo not hair
treat a scattered piece of geo as hair like cinema4d does ( mash cannot do it either)
think of bendy lego hair only


no mention of loading an actual named file in expression editor though
or why mudbox cannot load the xgen saved ptex?


#2

Try the Official Autodesk forum.


#3

Dont use the old xgen if you dont have TDs in your team. Use the new interactive one.

The old one is designed to work if you have a grooming department and store all data outside of maya. And create a library of delta files. Nothing you would do in a small studio.


#4

Regarding the ptex desity. Im not 100% sure but i think it does work like this.

A density of 5 means 5x5=25 pixel in your first face of the mesh. If your mesh does have 100 poly you create 2500 texel. If your mesh does have 1000000 poly you create 25000000 texel.


#5

my aim is “xgen scatter using geo say legoblocks,bent into hair like shapes using groom tools”
additionally using mudbox to paint higher detail ptex maps

in this tutorial he says
https://www.mikecauchiart.com/single-post/2017/08/29/Beginners-guide-to-XGen-pipeline-for-beginners

1 quote "To load a custom ptex map into xGen simply drag and drop the file path into the attribute you want it to

drive. Make sure that this path is relative and that the file is saved within the XGen folder."

how do you do this in an expression box NOT a texture file box

what do i type to load such a map in the expression editor
thinking is this even possible or is it some weird disney whoever
any file in that folder script?

in normal xgen not xgen interactive.

( my aim is hand sculpt bendy hair made of lego say)


so far found save your expressions elsewhere as no undos

found this set of tutorials hopefully better at normal xgen
https://jesusfc.net/tutorials/introduction-to-xgen/

learner errors i made, must do following

clean maya project path no spaces in names
clean geo, archive,collection,descriptions no spaces in names

archives geo world 000 freeze transforms

do not load archives till set all preview , render density and density to 0.01(absolute min)
to prevent massive geo crash MUST DO.

to assign say a density map
create map, save expression as no older version save

apply lambert1 map to surface ( better to assign every time you 3dpaint)
3d paint use solid brush black white for 0 or 1 hairs
3p paint softbrush blend
3d paint save texture or all painted info must as lost ( saved in source images, in each folder create a

sub folder
called “old” to drag in and keep older versions)

save ptex file ( saved in xgen collection descriptions paintmaps, in each folder create a sub folder
called “old” to drag in and keep older versions)
saving ptex freezes computer for maybe 5mins,ignore till ptex save button goes off this is slow!

most errors occur here sometimes it just will not update the ptexmap, redo wait another 5mins fails again
problem here you loose all access to maya, the hypershade, the xgen preview eye all freeze and lockup
while you attempt to work out why the ptex map didnt update. so loose 10 mins each time
ie 3dpaint path (seems to work first time then get confused as to where 3dpaint files lie) with different versions

{to substitute for mudbox ptex file drag in old folder, bring in mudbox ptex and give old name,
though this breaks 3dpaint link} this wasnt done on my example below was only in xgen

press eye preview update

my experience is please see: below my usual xgen expereience:
https://www.flickr.com/photos/93465359@N03/48556954822/
seems confused as to what was the 3dpaint path. plus full density black and white. plus ptex 5min
update account for all these and works

also wondered what uvs 3dpaint actually uses, all arnold tests show a square which would have same uvs in all formats so not really a fair example to switch iffs, it would always work on a square but maybe not on proper uv
or ptex uvs.


#6

From your cryptic text we have no idea what you are exactly doing.
Please provide some videos and the scene file. Otherwise we cant help you.
xGen is working fine if you know how to work with it.

I have a long thread over at cgfeedback containig a lot of tricks.
http://cgfeedback.com/cgfeedback/showthread.php?t=5303


#7

Hi oglu,
previous post gives current workflow:

still not getting old xgen to update its ptex maps after saving 3dpaint file,
as per previous post updated see pic at bottom, solved solution at bottom of pic

find xgen drops lambert 1 shader all time, then says no material assigned,
seems to get worse if you save another version of maya . i think there are background links
in xgen outside of 3dpaint and ptex directories that are getting mixed up.

MAIN ERROR CAUSE 1
is what your maya version is calling what 3dpaint file folder

for example if you have 3 versions of your maya file, and have only one 3dpaint file,
for density, but have been repainting the 3d paint file each maya version has a seperate
file that could be different but are all called the same thing, maya doesnt seem to
know which 3dpaint file it is calling on to create the ptex and as a result creates a blank
ptex

MAIN ERROR CAUSE 2
not using solid black , white paint in 3d paint tool

MAIN ERROR CAUSE 3
ptex save time 5mins min cons user it has failed when might be ok.

anyway 5min plus ptex saves making it unusable.
prefer if it at least showed the ptex saved map in the viewport

(this is before we get to the mudbox errors, as got to get xgen working properly first.
my workflow does not include mudbox yet) probably useless as cannot see existing hairs

my experience to date:below
https://www.flickr.com/photos/93465359@N03/48556954822/

seems confused as to what was the 3dpaint path. plus full density black and white. plus ptex 5min
update account for all these and works

also wondered what uvs 3dpaint actually uses, all arnold tests show a square which would have same uvs in all formats so not really a fair example to switch iffs, it would always work on a sqaure but maybe not on proper uv
or ptex uvs.


#8

Yes xgen overwriting the last version. If you need version control you have to use an other external system.

That xgen cant save a file is a windows behavior. You have to close maya and reopen it.

As i mentined above if you dont have TDs dont use the old xgen.