Retopo - Should Poles be avoided completely?

DustyShinigami

Hi

Like the question asks - should they be avoided completely or are they fine in some situations? In my example, I've added one on the surface of a mech's leg, though it's not an area that should be affected negatively when deforming.

Thanks

Neox

avoiding poles is generally more of a movie pipeline kinda thing that applies do deforming meshes. in the sense of a highpoly model for game context the important question is, does it shade well? if it does (like in your case on a flat surface, it doesnt matter).

for the lowpoly it also is more a matter of convenience while working on the asset, in engine, everything is triangles anyways, so whatever works, if it looks good.

DustyShinigami

Cool. Thanks for the heads-up. I know I did get feedback for a character at one point where there was a Pole around the legs or pelvis...? But I presume in those cases they'd need to be removed because of deformations.

I did do it initially for convenience, though I have changed it just in case. But good point about the triangulation.

Neox

if its really just for a lowpoly. you might as well do it similar to this. feel like you do not need these extra loops around the holes or inside. more like its something you picked up from highpoly modelling. if this is supposed to be a basemesh for a highpoly, i feel like its all a bit too messy. anyways. any reason you do a retopo and not just work with the basemeshes?

DustyShinigami

Hmm. Okay. But yes, this will be for a new high poly. The original high poly was made using Fusion 360, and on export it's converted to tris. Sadly, most of it was too much of a pain to ZRemesh cleanly. So I decided to retop it so I can create a new high poly from it as well as the low poly.

But I'll try what you've suggested. I've always been a bit unsure how best to tackle things like alcoves and holes and then link them up to the rest without making it more denser.

DustyShinigami

Neox said:

if its really just for a lowpoly. you might as well do it similar to this. feel like you do not need these extra loops around the holes or inside. more like its something you picked up from highpoly modelling. if this is supposed to be a basemesh for a highpoly, i feel like its all a bit too messy. anyways. any reason you do a retopo and not just work with the basemeshes?

Okay, I'm a little unsure about these areas:

There may be quads in the middle, where the 3 pink centre lines are, but that's going to leave tris like this...

Neox

oh nevermind these ramblings, as i expected this to become the lowpoly not the basemesh of a new highpoly. i really suggest you learn how to model this instead of doing it in cad, then remodelling it again to make a new highpoly. usually what you would do, make the cad model, bake that down to the final lowpoly

DustyShinigami

Neox said:

oh nevermind these ramblings, as i expected this to become the lowpoly not the basemesh of a new highpoly. i really suggest you learn how to model this instead of doing it in cad, then remodelling it again to make a new highpoly. usually what you would do, make the cad model, bake that down to the final lowpoly

Well, it'll be both - the new high poly and a low. The plan is to retop it to get cleaner topology, crease the hard edges, subdivide it in ZBrush to make a new high poly, and then drop down to a lower subdivision to get the low poly. I made the CAD model, which looks great, but as I say, you can only export them and then they're triangulated, which makes everything look messy and faceted to bake with. :-\

I took up making it in Fusion 360 because I hadn't used it properly before and wanted to learn another package. Plus it's ideal for hard surface modelling. I've already learnt how to do sub-d modelling and hard surface in ZBrush, so thought I'd give another approach a try.

pxgeek

I'd be curious to see how the exported cad model looks like in zbrush or dcc app. It sounds strange that it would be unusable for baking. Maybe it's an export setting, like a resolution slider or something? (Keeping in mind that triangles aren't inherently bad...we've been baking decimated meshes for a long time now)

Having to remodel your low poly to make a new high poly kinda defeats the purpose of using cad in the first place.

I don't use Fusion 360, so I googled it and came up with this:

https://www.youtube.com/watch?v=bNHAjjUCZdw 

Maybe that'll help?

DustyShinigami

pxgeek said:

I'd be curious to see how the exported cad model looks like in zbrush or dcc app. It sounds strange that it would be unusable for baking. Maybe it's an export setting, like a resolution slider or something? (Keeping in mind that triangles aren't inherently bad...we've been baking decimated meshes for a long time now)

Having to remodel your low poly to make a new high poly kinda defeats the purpose of using cad in the first place.

I don't use Fusion 360, so I googled it and came up with this:

https://www.youtube.com/watch?v=bNHAjjUCZdw 

Maybe that'll help?

Huh. That's certainly one way of doing it. I suppose with that method, the extra geometry would smooth the mesh out...? I think it's more of an OCD thing with me. I don't even decimate a high poly to bake with. I'll do it so I can retop from it as it won't be as big of a file size, but I can't stand the idea of baking from a mesh that's incredibly faceted and is covered in dings and dents etc. They especially stand out like a sore thumb when I bring them into 3DCoat. I think a couple of years ago I tried using one to bake with and it transferred all that to the baked maps. :-\

It would be ideal to make use of the CAD model as the high poly though. But as I'd need to retop it anyway to make a low poly, it won't take much to create a new and cleaner high poly from it. I'm essentially using the method I've used with characters, where I'll sculpt a high poly, retop it, unwrap it, and transfer the details from the original high poly back to get a cleaner high poly. But I'm certainly down for finding/using an alternative method if it's posslble. I'll give that method you linked to a try and see what it looks like in ZBrush.

DustyShinigami

pxgeek said:

I'd be curious to see how the exported cad model looks like in zbrush or dcc app. It sounds strange that it would be unusable for baking. Maybe it's an export setting, like a resolution slider or something? (Keeping in mind that triangles aren't inherently bad...we've been baking decimated meshes for a long time now)

Having to remodel your low poly to make a new high poly kinda defeats the purpose of using cad in the first place.

I don't use Fusion 360, so I googled it and came up with this:

https://www.youtube.com/watch?v=bNHAjjUCZdw 

Maybe that'll help?

So far I'm not finding the options the guy uses in the video. :-\ It was posted 2 years ago, so it looks like things have changed/been renamed or something.

EDIT: Oh. Never mind. Turns out someone had the same issue and asked the guy in the comments. It's been changed and it falls under Tessellate now. There's also an option to use Quads in there, too. I would say the results are similar to how Marvelous Designer's topology works, so it still uses tris in places. Also, it looks like it creates separate materials, or what look to be Polygroups. However, I've not figured out how to export it that way. Following the method in the video, or exporting it as an OBJ still converts it all into triangles. :-\

sacboi

Even with my limited knowledge working with solids (double precision), you're assuming bottlenecks where they don't exist when generating game ready meshes:

Game-ready Lowpoly asset from Fusion 360 Workflow Guide

DustyShinigami said:

 But I'm certainly down for finding/using an alternative method if it's posslble....

but personally, I'd suggest a more 'artist friendly' approach, with a CAD based NURBS workflow - by implementing Plasticity 

(...you can thank me later and btw those complied vids were also authored by the dev, as well) 

pxgeek

I was genuinely curious about a cad workflow, and after doing some digging it seems like fusion's mesh conversion problems are pretty well known (on AD forum). And of all the cad for games tutorials I found that use fusion 360; the one common thing was that they all required Moi as an intermediate for export

I don't know if you'd care to share pic of how your converted mesh looks like in maya/max/blender? (Just a bit of morbid curiosity on my part...lol)

Plasticity looks amazing though! The mesh conversion options looks exactly like what you would want.
They have a free trial too. It might be worth it to try and import your fusion model as a STEP file into Plasticity and see if it can spit out a cleaner high poly for you.

DustyShinigami

sacboi said:

Even with my limited knowledge working with solids (double precision), you're assuming bottlenecks where they don't exist when generating game ready meshes:

Game-ready Lowpoly asset from Fusion 360 Workflow Guide

DustyShinigami said:

 But I'm certainly down for finding/using an alternative method if it's posslble....

but personally, I'd suggest a more 'artist friendly' approach, with a CAD based NURBS workflow - by implementing Plasticity 

(...you can thank me later and btw those complied vids were also authored by the dev, as well) 

Thanks for the links. I'll definitely look into those for a future project, particularly the Plasticity workflow. Not heard of that one before. Is that exclusive to Blender at the moment? Not that that's an issue or anything. Was just curious.

Also, regarding the game-ready low poly workflow, I think I've come across Mol3D before, but I'm not 100% I see you have to pay for it, but is it a one-time payment? I take it dastagir made it in Fusion and then took it into Mol3D to do some final tweaks...? Just a bit confused as they mention they worked with Fusion at the start and then suddenly they say it was done with Mol3D. I've still yet to try RizomUV, too. I've heard from a friend it's supposed to be really good for unwrapping.

DustyShinigami

pxgeek said:

I was genuinely curious about a cad workflow, and after doing some digging it seems like fusion's mesh conversion problems are pretty well known (on AD forum). And of all the cad for games tutorials I found that use fusion 360; the one common thing was that they all required Moi as an intermediate for export

I don't know if you'd care to share pic of how your converted mesh looks like in maya/max/blender? (Just a bit of morbid curiosity on my part...lol)

Plasticity looks amazing though! The mesh conversion options looks exactly like what you would want.
They have a free trial too. It might be worth it to try and import your fusion model as a STEP file into Plasticity and see if it can spit out a cleaner high poly for you.

Ohhh, so that's what Mol3D is used for after Fusion...? I see, I see. Curious how that converts things. Does it have some sort of advanced quadify tool?

Based on the initial screenshots I saw, I thought Plasticity was something in Blender due to its UI. But no, it's its own software. Cool. But yes, I'll give it a quick try and report back.

But sure, I can share some pics. I have it set up in Maya.

I did try adding smoothing to a part of it, but like I suspected, it causes pinching and weird shading.

DustyShinigami

Well, Plasticity certainly seems more simplified to use than Fusion, and it allows you to export meshes out in Quads as well, though with some triangles. I imagine it'll probably look smoother when you increase the density of it.

However, I don't know if there's an option to toggle on the Wireframe version to see how everything's looking...? Also, can you sketch designs like in Fusion?

DustyShinigami

Okay, so this is how one piece looks after being quadified in Plasticity:

Adding smoothing was perfectly fine as well. However, if I add any additional subdivisions, the whole thing becomes facetted, and adding smoothing creates shading/pinching issues. So it's most likely best to set it how you want in Plasticity first and leave it at that. I'll try another mesh...

Yeah, this is lightyears way better than manually retopping and creating a new high poly.

pxgeek

Thanks for sharing your maya screens,
It's interesting to see how fusion has chosen to allocate the geometry.

And yeah, the Plasticity export looks way better.
Why fusion cannot do something similar is just....strange.

DustyShinigami

Agreed. It is strange. I don't know - maybe it's because it's primarily for manufacturing and design purposes...? The few I've spoken to on the Autodesk forum don't come from a game development background so some of my approaches/workflows were alien to them? They're very particular about constraining sketches and having the measurements correct etc. I do like the Sketching in Fusion though. It's certainly nice to have a CAD software similar to it aimed at artists though.

DustyShinigami

I've done a bit more experimenting. I've tried getting my entire high poly model from Fusion exported out with the help of Plasticity, but the final export has completely changed in scale. :-\ I did import an OBJ version from Fusion first, which I think is the right scale, but there's no Near/Far Plane Clipping option in Plasticity to adjust from what I can see. I've no idea if there are more options available in the paid for version. Also, there's no way I can zoom out any further, which results in it being slightly cropped from view.

However, if I export a STEP file from Fusion into Plasticity, you can toggle individual parts on/off, but the scale is much smaller for some reason. I have it set to centimetres in Fusion AND Plasticity. Though I can zoom out more. I've then exported everything out of Plasticity with the appropriate level of tessellation and quadify and imported it into Maya. This shows for definite the scale is adjusted when comparing to the OBJ export from Fusion.

Soooo, yeah... Not sure what's going on there. Nor how to keep the scale I put it to, which should be around 609.60cm tall.

DustyShinigami

Sent Support for Plasticity an email asking about the exporting/importing and scaling issues and it looks to be because STEP has unit information, but OBJ doesn't. Either way, it's inconsistent between programs, which isn't good or convenient.

poopipe

I don't think anyone's really solved that except to have scale adjustment on their obj importer. 

there's not a lot you can do except keep your units consistent between applications

DustyShinigami

poopipe said:

I don't think anyone's really solved that except to have scale adjustment on their obj importer. 

there's not a lot you can do except keep your units consistent between applications

The only thing I can think of is to just export as an OBJ from Fusion, which will keep the scale once it's in Plasticity, and then export from there as quads/tris. The only downside with that, is I find I'm unable to zoom out very far from the model, and everything is merged into one object rather than parts. Thankfully, it's pretty easy to select each element once you're in Max/Maya/Blender etc.

But yeah, they do need some sort of OBJ importer.