Need help exposing Material ID's on object made in 3ds Max

[Snappy_Darko]

Hi, 
 

I need some help exposing materials on an object made in 3ds Max.  Im modeling the assets in 3ds Max and sending them into Houdini to Unwrap, before sending them on to Substance Painter (then on to Unreal).  It's a workflow that worked excellently when using Zbrush instead of Max, but i can't quite get Max to work with Houdini. 

Here is a visual example of what im getting across these softwares. The issue is that the material ID's i created in 3ds Max aren't locatable in Houdini.  Ive tried exporting the objects from Max as .obj, .abc, and .fbx, but i just cannot get it to work like i did with zbrush, where you just make sure the polygroups are polypainted on the model before exporting/goz'ing to Houdini (polygroups/polypaint being zbrush's version of 3ds Max's material colour ID).  

Could someone please take a minute help me out.

Many thanks

[Noobini]

seems to work ok for me

01) assign Mat IDs to whatever groups/elements in Max

02) use standard materials of diff colours for visualisation

03) assign multi sub obj mat to object

04) export FBX embed media, ie the material you setup.

05) in Houdini, File>Import>FBX....

You'll see Houdini has done partition into groups for you...and assigned default mat to each prim group

 

vu_MatIDs.zip

Edited March 4, 2020 by Noobini

[Noobini]

You can also do it via vertex colours in Max, not needing the use of a multi subobj material.

then in Houdini, use a partition to group, based on Cd.

...but I think it's far nicer to go with the material in Max and let Houdini automagically set up the material in Houdini for you.

[Snappy_Darko]

22 hours ago, Noobini said:

seems to work ok for me

01) assign Mat IDs to whatever groups/elements in Max

02) use standard materials of diff colours for visualisation

03) assign multi sub obj mat to object

04) export FBX embed media, ie the material you setup.

05) in Houdini, File>Import>FBX....

You'll see Houdini has done partition into groups for you...and assigned default mat to each prim group

 

vu_MatIDs.zip

 

Thanks, though when i bring in the FBX the material groups aren't retained. The first image is from Max, with all the materials applied (as multi/sub-object), but then Houdini sem to ignore sections of the model (the windows, the seat) as well as create a heaving looking yellow mesh.  Im pretty new using this program, can you tell where i might be going wrong?

 

 

last image here is what the material setup looks like

 

Edited March 5, 2020 by Snappy_Darko

[Noobini]

so you did embed media right ?

or else just upload your fbx file and I'll see how it imports here.

[Snappy_Darko]

Hi, yeah i made sure emded media was ticked when i exported it from Max

Edge_Low.fbx

[Noobini]

ahhhh...this is why I said to use standard material in Max...chances are...if you did use some other fancy material...say vray for example...there's no guarantee the export process will convert these materials correctly...hence...in Houdini a couple of them went missing. But that's not houdini's fault.

If you use Max, import your fbx back in, you'll see it says it has 4...that's right count them....4 materials

Hence...2 went missing during the export. Red an and Yellow I think.

Stick to standard material only...so they become the good ol' Phong I think.

(prolly a good idea to forget about transparency too...export might throw its hands up and say I don't know what to do with this)

Edited March 5, 2020 by Noobini

[Snappy_Darko]

Thanks, did you work that out from viewing the file i attached?

Im a bit of a noob in max myself, and see there are a variety of different materials i can choose from, which would say confrom to a 'standard' material?  

Weird thing is im pretty sure i did use a standard material though

[Noobini]

yes in Houdini I got 4 mats...hence I checked importing in Max and that did say there's 4 materials in the fbx file so that pointed to it's already dead in the water during the export process.

So since you know 4 of them worked...just blow away the current red/yellow. Shift drag out one of the other working ones, and change the colour to be red or yelllow.

in Max, under materials>Scanline there's one called standard...use that.

Edited March 5, 2020 by Noobini

[Snappy_Darko]

15 hours ago, Noobini said:

yes in Houdini I got 4 mats...hence I checked importing in Max and that did say there's 4 materials in the fbx file so that pointed to it's already dead in the water during the export process.

So since you know 4 of them worked...just blow away the current red/yellow. Shift drag out one of the other working ones, and change the colour to be red or yelllow.

in Max, under materials>Scanline there's one called standard...use that.

Thanks for your help.  Ive ended up detaching every part in Max and importing it that way, seems to preserve the different regions of the mesh.  Just using the material editor didn't work. Thank you

 

Edited March 6, 2020 by Snappy_Darko

[Noobini]

naaaaah...that sounds like a real PIA for your workflow...

- your orig geo did NOT have all polygons properly assigned to materials...ie. you had 6 mats...but your geo had only 4 groups properly assigned so 2 of the mats were useless.

- your alpha was screwed, hence in Houdini you saw the weird ass see through yellow lines

So, I made all your polys alpha = 100 in Max, assigned to use all 6 mats...just works, here's how it looks in Houdini

 

 

 

 

Edge_Low_fixed.fbx

 

alpha & mats assigned:

Edited March 6, 2020 by Noobini

[Snappy_Darko]

Thankyou so much for this, just getting back to this now an realising I wasn't making Materials ID's - i was just applying Mats (I didn't know the difference).  I actually couldn't access the .fbx you linked, either in Max or Houdini, but I followed your instruction to turn the Alpha to 100% and to do the Material ID groups.  I am getting the material channels in the FBX when I open it in Houdini, but they are not visualised/coloured like yours - most of the model is black, even though parts of the model are separated. It; not a big deal, but still really annoying that I can't get it working perfectly.  Heres' the new .fbx that I made 

My_attempt_fix.fbx

also, my 2 fbx's are importing to totally different locations and both at object level -  if i wanted to do an exploded bake together they would need to be at the same sub-object level, but there doesn't see to be a way for importing them both to the same sub-object context.

Edited March 10, 2020 by Snappy_Darko

[Noobini]

your geo seems to have all vertex color set to black.

I've fixed it here, also centered it. Make sure you login to download.

 

Geo_centered.fbx

[Snappy_Darko]

7 hours ago, Noobini said:

your geo seems to have all vertex color set to black.

I've fixed it here, also centered it. Make sure you login to download.

 

Geo_centered.fbx

Thanks, that works fine now. 
Can I ask why .obj files don't carry this Material ID info into Houdini?  FBX, afaik, establish contexts only at object level which makes merging a high and low FBX for doing an exploded bake impossible (which need to be at sub-object).

[Noobini]

dunno...maybe obj is just too ancient ? but it could work with obj using other means like vertex colours rather than mats...

[Snappy_Darko]

2 hours ago, Noobini said:

dunno...maybe obj is just too ancient ? but it could work with obj using other means like vertex colours rather than mats...

ok, right. sorry for all these noob questions, your time's really appreciated.  It's just been a slow getting used to the 3ds max workflow - it was much easier working with Zbrush - the goz tool made things extremely simple.

Just lastly, on the bakes ive done, i keep getting artifacts - visible on the normal map only (the white/grey model picture).  I've tried flipping the normals on the Y-Axis, but still getting the artifacting.  Ive baked it numerous times with difference settings, but just no luck.  Ive noticed that Houdini completely changed the geometry on the FBX - turned everything into triangles..could this be what's creating the artefacting?

Im so near to getting this sorted and being able to get on with just texturing these things in Painter (that im much more familiar with), but this last hurdle has me stumped.   

edge_high.fbx

edge_low.fbx

[Noobini]

just FYI, you know there's GoZ in Houdini right ?

it's in the sidefx Labs shelf

[Noobini]

if using alembic, assign vertex colours to different groups in Max, then Houdini picks it up nicely...and quads preserving.

Geo_centered.ABC

vu_testAlembic.hiplc

[Snappy_Darko]

Thanks again Noobini, ill try alembic for the quads preserving.

Yeah, the Goz tool i have been using for ages between Zbrush and Houdini, the workflow was seamless and created a file containing all the Material ID groups without having to mess around with FBX's and the string of contexts the FBX file type creates upon import into Houdini.  But.. i had to switch to 3ds Max for the modeling reasons - much better for larger-scale things.