Converting Body Objects into clean and editable topology?

[Kirsten Zirngibl]

Hi,

 

I wish to convert many imported .iges files into quality meshes with the ability to select edge loops. These .iges files come into Max as "body objects." I am not given any settings when I import, they just come in. The software they came from ("Gravity Sketch VR") didn't give me any exporting options either.

 

So, while in Max, while I can "convert to editable poly" or apply a "turn to poly" modifier, the resulting mesh is very poor for editing with my usual workflow. I cannot select edge loops, and the mesh is in triangles. I also find that none of the "turn to poly" modifier settings make a difference. Quadrify also didn't do anything to the triangles.

 

I thought that perhaps "Polynurbs 1.0" could do the trick, but body objects aren't NURBS so it doesn't work... This looks promising for turning them into NURBS, but is almost $200 and I'm not 100% sure it would do what I want.

 

It seems like this should be natively possible somehow... I'm in Max 2015.

 

This person is recommending Rhino for a body-object-to-nurbs step, which I will consider a last resort, since I don't have Rhino and was not prepared to buy/learn it right now. But I will also do what I have to to make good use of these .iges files, too.

 

Any advice/strategies? Thanks.

 

Edit: Here's an image example of the weird topology I get after converting to edit poly directly in Max...

Edited January 3, 2018 by kirstenzirngibl

[matevzavbelj]

Looks like a triangulated mesh. Try Quadify modifier to turn it into quads, should do the trick (weld vertices before doing that as well). Or you could zRemesh it in Zbrush if all else fails.

Edited January 2, 2018 by matevzavbelj

[Kirsten Zirngibl]

I realize it's a triangulated mesh (a somewhat messed-up one), and had already tried "quadrify" on it, but that only divided things into smaller triangles. Ideally the solution lies into body object->better topology within Max or a plugin within it. The goal is the ability to select edge loops.

Edited January 3, 2018 by kirstenzirngibl

[Josef Wienerroither]

Looks pretty messed up - inconsistent normals etc... if you only got this as edit poly, you are pretty much out of luck for anything better

in that case, i would turn it to edit mesh and try a unify normals. But in any case, Quadrify or similar tools will not get you anywhere on this kind of tesselation.

You don't have by any chance the original file ( some CAD data format ) ?

I seem to remember that the nPowerTools importer has a quad output flag in the mesh tesselation options

[James Vella]

I realize it's a triangulated mesh (a somewhat messed-up one), and had already tried "quadrify" on it, but that only divided things into smaller triangles. Ideally the solution lies into body object->better topology within Max or a plugin within it. The goal is the ability to select edge loops.

 

Do things in this order:

1. Weld verticies

2. Unify normals

3. Quadry mesh (do this in the ribbon layout - not as a modifier it makes a huge difference - Modelling > Geometry (All) > Quadrify All)

 

 

 

Edited January 3, 2018 by redvella

[Kirsten Zirngibl]

Looks pretty messed up - inconsistent normals etc... if you only got this as edit poly, you are pretty much out of luck for anything better

in that case, i would turn it to edit mesh and try a unify normals. But in any case, Quadrify or similar tools will not get you anywhere on this kind of tesselation.

You don't have by any chance the original file ( some CAD data format ) ?

I seem to remember that the nPowerTools importer has a quad output flag in the mesh tesselation options

 

Unfortunately I don't have such a CAD file. The .iges file was exported from Gravity Sketch VR.

 

Do things in this order:

1. Weld verticies

2. Unify normals

3. Quadry mesh (do this in the ribbon layout - not as a modifier it makes a huge difference - Modelling > Geometry (All) > Quadrify All)

 

Many thanks, that did the trick! I actually didn't know I could quadrify from the ribbon like that. Learn something new every day. there is an art to welding it so that I don't get "broken" edge loops from the occasional triangle, but it is much better than it was.

[James Vella]

Excellent great to hear

[Josef Wienerroither]

While this produces a quadified mesh, i can't really see it being more "editable" in the human sense. Can you post a screenshot of the quadified mesh ? Problem with that is that most Quad's will not be flattened but consist of several distorted inner triangulation ( vertices of a quad will not sit on a plane) . This will most likely produce problems with the normals while editing and when rendering later on

 

Is the mesh posted above the original mesh you have to work with or is it just an example ?

I really would be interested to get the original mesh in hands and try ( and succeed or fail ) on it myself

Edited January 4, 2018 by spacefrog

[Kirsten Zirngibl]

While this produces a quadified mesh, i can't really see it being more "editable" in the human sense. Can you post a screenshot of the quadified mesh ? Problem with that is that most Quad's will not be flattened but consist of several distorted inner triangulation ( vertices of a quad will not sit on a plane) . This will most likely produce problems with the normals while editing and when rendering later on

 

Is the mesh posted above the original mesh you have to work with or is it just an example ?

I really would be interested to get the original mesh in hands and try ( and succeed or fail ) on it myself

 

The posted mesh was just an example. The reason it's more editable to me is that I can select edge loops.

 

I understand what you mean by vertices that don't lie on a plane.

 

The intention of doing all this is to create many quick conceptual buildings in VR using Gravity Sketch (a whole cityscape's worth), then add detail such as struts and floors in Max by selecting edge loops that contour the form-- and creating splines from them using "create shape", then lofting those, or filling them in as new geometry. This would have to be done many times which is why double-click-edge-loop select is important to me.

 

I did try rendering that example mesh after quadrifying it, and it looks perfect - no jaggies. However, the topology itself is not perfect in that it didn't all turn to quads. There are still some triangles which impede the ability to select edge loops around the entire form. It's still better than none at all though.

 

Attached is an example mesh (more like what I'm going to be working with, but still pretty crude). The .max file has both the .fbx and .iges imported, and I included the raw exports from the VR app as well. As you can see, not all the .iges shapes came in. I also noticed the file had a lot of "curve" objects that didn't appear to BE anything in the viewport. I put those in a separate layer.

 

https://www.dropbox.com/sh/2c40lui5slzoqdo/AACxPM7YeGpQIhvZSa10Civza?dl=0

 

Many thanks for offering to take a look!

[Josef Wienerroither]

Okay: had a look at the files

 

IMHO best is to import the IGES file as bodyobjects ( flattend hierarchy ), set the body objects tesselation to coarse/very low value, once you a happy with the tesselation ( turn on edge display and switch to display as mesh, other wise you want see the mesh tesselation ), add a Quadify Modifier at 100%. After that add an Edit Poly modifier to be able to use the Quadrify All functionality from the Polytools ( ribbon ) and or edit manually by hand, On top of that you can place an Mesh smooth to go back to a nicely tesselated mesh. Most critical of course is the inital tesselation from the body object, there are a lot of parameters ( Body Objects Viewport Display Settings )to tweak accordingly which are always specific to the individual model, so this cannot be really generalized

 

Anyways i created a macroscript to help with such conversion tasks:

 

Download BodyQuads macroscript

 

* Simply install and place the action ( Category Spacefrog->BodyQuad ) on a toolbar

* select your (imported) body objects and click the button to create the according modifier stack ( low tesselated )

* CTRL + Button click produces a higher tesselation modifier stack

* ALT + Button removes the created modifiers and returns the body object to the initial settings ( possibly DESTRUCTIVE ! )

 

The round, lathed objects in your example files are good candidates for the standard/lowres version. The organic surfaces are more fit to the CTRL+click ( higher resolution ) version of the modifier stack. But as i said for finer tuning you want to adjust the body objects tesselation manually, you can easily delete the generated Edit Poly modifer and apply a new one after those tweaks, and run the Quadrify All cycle on this

Below is a screenshot of the unmodified output ( meshsmooth was disabled ) of the script on your sample file. The large organic surfaces were produced using "CTRL click" ( higher tesselation )

 

Edited January 6, 2018 by spacefrog

[jackbird]

Off-topic - are you the one using Gravity Sketch? If so, how do you like it? The subscription price is a bit steep for a tool without a clear immediate use case, but it looks like a tool that would be great o have in the office for conceptual sketching.

[Kirsten Zirngibl]

Okay: had a look at the files

 

IMHO best is to import the IGES file as bodyobjects ( flattend hierarchy ), set the body objects tesselation to coarse/very low value, once you a happy with the tesselation ( turn on edge display and switch to display as mesh, other wise you want see the mesh tesselation ), add a Quadify Modifier at 100%. After that add an Edit Poly modifier to be able to use the Quadrify All functionality from the Polytools ( ribbon ) and or edit manually by hand, On top of that you can place an Mesh smooth to go back to a nicely tesselated mesh. Most critical of course is the inital tesselation from the body object, there are a lot of parameters ( Body Objects Viewport Display Settings )to tweak accordingly which are always specific to the individual model, so this cannot be really generalized

 

Many thanks for taking a look! The script indeed works great for the lathed objects.

 

For the irregular surfaces, things got pretty funky. I've been playing with the body object's initial parameters with some success, although it seems impossible to get it "perfect." But being able to select partial edge loops still saves me considerable time when I need to wrap geometry around the surface.

 

I still can't figure out what's happening with the flat shape information, though. It shows up in the FBX but not the IGES.

 

Another missing piece of information from the iges import is "stroke" information (basically, lofted splines). In a different test, it appears something is coming in, but nothing is showing in the viewport. (below)

 

(Test file fbx/iges here: https://www.dropbox.com/sh/vscqhlokh5g72bx/AAA0n0nswHqitZ1RtWx-l-HEa?dl=0)

 

Off-topic - are you the one using Gravity Sketch? If so, how do you like it? The subscription price is a bit steep for a tool without a clear immediate use case, but it looks like a tool that would be great o have in the office for conceptual sketching.

 

Indeed I am! I haven't been using it for long, but already I see it as a gamechanger for how I work. One caveat: I'm not using it for the traditional architecture industry, but instead for design work in video games (sci fi architecture and vehicles), amusement park design, and the creation of environmental assets for a trippy VR project. It's amazing for design work because it seamlessly combines the 2D composition/shot design with the 3D form design, facilitating a kind of dialog between the two that feels natural. I have been trying various ways to design straight in 3D, and the tool always tended to mold my vision to its paths of least resistance. Rough work in gravity sketch is the "purest" approach I've encountered so far.

 

Another utility it serves is the creation of splines and surfaces that curve in >1 dimension, quickly and intuitively. (Dealing with those in Max was always a pain in the @$$.) This is why I'm so keen on importing those into 3DS Max as well as possible. Also adding geometry exactly where I want it (whether than having to create then move it afterward) is very useful.

 

It also blows the likes of Tilt Brush out of the water because of its edit-ability, the ability to adjust each stroke/surface after creation.

 

I do agree the price is steep, and would not commit to a year subscription, especially since I haven't ironed out all the Max import issues yet... But at the same time, I do really want to support early efforts to create art tools for actual professionals rather than toys. This method of creation has so much promise, and they are probably fighting an uphill battle right now.

Edited January 9, 2018 by kirstenzirngibl