Brandon Wehenkel: Independent Study (Update 3)

The purpose of this study here, for a turntable, go here.

I need to make the file 3D printer friendly, which has taken all four weeks.  Still behind but slowly getting things done.  My goal for this session was to create keys for all of my geometry so I can finalize my file for printing and make my goal for removable parts valid.  The biggest problem is that it took ages to do anything because Maya crapped on me every place I tried.  At home, in the lab, and in the student lab on the 2nd floor; my personal computer was much faster than all other locations, and it was a snail’s pace. I tried Zbrush to clean up the hole but I am all too uninformed on the application, so it was not very helpful this time around.  I will need to know how to use that application when I want to do this process again,

Problem 1:
First thing to mention, as I was working on transferring data from Mudbox to Rhino back and forth, I came across a minor issue with Rhino increasing the size of all the .obj imports.  I discovered that 500k polys for the body and sitting figure are still too much.  Rhino craps out when the objects are booleaned or trimmed in any way.  So I had to go back into Mudbox to decimate again.  The torso, legs, and sitting figure are below 150K polys.  The arm is at 70k polys.

Cutting reference

Problem 2:

Working in Maya is slow!!!  Imagine doing append a poly once every 17 minutes, and you have to repeat the command 46 times. I needed to cut the models in parts to fit the 3D printer.  What I discovered was that Rhino and Mudbox do not fill holes very well.  Rhino's hole fill tool does not clean the topography when applied. It creates triangles with a lot of connecting points in the middle creating an ugly seam and pinches the geometry when required to extrude.  When importing into Mudbox after modeling in Rhino creates multiple overlapping layers with holes as well as jacks up the topography when cleaned with the patch tool, making it not worth my time.  So I was stuck in Maya to fix this problem.  After spending about 3 hours and only appending 16 faces out of 46, I had to think of something else.  Maya has a fill hole tool as well, it only does half the work, unfortunately, requiring the use of the interactive split tool.  Extrude took 2 hours at most for some locations on the arm.   Hole fill takes 3 hours to complete.

From 11:50 am Sunday, March 26 to 3:26 am Monday, March 27th I appended one polygon.  I do not know what the problem is but Maya does not like my arm mesh.  Saving, restarting the computer cleaned up some of this wait time.

 MUDBOX HOLES

Referring to what I mentioned earlier, after working in Rhino and importing back into Mudbox.  The .obj creates holes in the topography and recreates topography errors denoted by the red dots.  The black texture problems around the fingers were not being picked up as errors but were in fact errors.  Every black section is a hole where the geometry is overlapping.  I did not continue to work with this mess.  I returned to Maya and used filled holes to start the key instead.

A part of problem 2, I needed to create a key, but the program took ages even to get this far.  This took 3 hours to get this far.  Restarting the computer managed to alleviate the time issue, but it still took about 4-20 minutes per each append poly/ insert edge loop/ interactive split tool/ merge vertex command.

Modeling Techniques:

The very first thing I had to do was cut all the pieces in the way I wanted.  I used all three programs, Rhino, Mudbox, and Maya to make these cuts.  I figured out that Maya was the more accurate program to do these cuts.

Photo of all cut pieces.

Cutting took about two weeks, unfortunately. How do you ask? It seemed like a simple task, but I needed to go back and forth between Mudbox and Rhino to see the parts and how they aligned up.  I would cut then fix the geometry, revert then cut again, fix the geometry, then revert and it took about three days to do that for the torso alone. I had to align the files overlapping each other till I found the most accurate place to slice.  It was a bit annoying for me because in real life you could pick up the objects and place them where you wanted.  In the 3d view window there isn't resistance when overlapping, so parts such as the fingers would be intersecting in the hooves while the other half of the geometry would be perfectly aligned in the arm.  It took much finesse to find the right spot.  I saved the perfect alignment pieces as an.Obj and imported it into Mudbox to clean up the geometry again, so that the seams were cleaner for cutting.The most straightforward part to cut was the arm.  However, it still was annoying because the geometry from my sculpted object is not completely round.  I fixed it as best as I could, but there's still some post work I will need to do with my Dremel tool hopefully in April.


Problem 3:

Rhino does not like the number of polys I have in one file so doing any modeling was terrible.  I tried to do boolean commands, but nothing worked how I wanted.  Most of the commands froze and crashed the program.


Mudbox created holes, third photo above.


In Maya, I used the interactive split tool and split polygon tool with edge selection turned on to cut the objects. I used the splitting objects & detaching commands to make the program know its two different objects.  Unlike Rhino when you use a boolean (to do the same process), Maya still thought the objects were the same, so I needed to delete the history for it to forget the changes.


I watched a video on youtube for making keys (pegs for the models to interlock) in Zbrush and used some of that knowledge for making it in Maya.  I would be better off in ZBrush, based on the struggles I have had so far.  I needed to make keys for my models.  I started with the smallest polygonal mesh (70k), the arm, on 22 March, four days later it still wasn't finished.

 The highlighted poly took 3 hours to create, 

and the geometry still looks like garbage.

I used extrude tool to begin the peg. I used the interactive split tool, append a poly, and merge tool to create the skeleton of the peg.  The topography was not right by 11:50 am Sunday, March 26.  Moreover, as of 5:28 Monday, March 27 the shape, direction, and topography of the peg has changed minimally.  The whole process is not worth the wait in Maya.
After completing the key for the arm, I have to repeat the process for the torso. Then I can invert the geometry scale it slightly and insert it into the holes of the arm (of the legs geometry) and sitting/legs portion.  Not sure exactly what the problem is regarding why everything is so slow because nothing is more significant than 150K polys.  Does Maya not like that many polys?


 Problem 4:

As of 4/2/18 12:08am, just as I thought I could continue to the next step of my process (making inverse keys) I find this odd colored geometry intersecting the eye and ear.  This wasn't here before when I was working in mudbox.  All these .obj conversions between mudbox, maya, and Rhino really screw things up. Deleting the colored mess creates boundary errors.  I gotta figure out how to quickly close open boundaries in Maya.  Edge merge doesn't seem to work for me.


What I have left regarding printing is to create an inverted key for the other parts. 

Brandon Wehenkel: Independent Study (Update 2)

Comparison

Since I already established the purpose of this study here, I won't need to reiterate the exact same thing again for this and the next two posts.  Unfortunately, by the time I created my first blog post I was already 3 weeks behind.  The scanning process was an utter nightmare for me, and I've understood that I may have made my sculpture a bit too detailed (I still wanted more detail too) and too large for the scope of the NextEngine 3D scanning device.  This time around I spent many hours after normal business hours in the lab working in the RapidWorks application.  The first week of February was nothing but hole filling and retopologization for the standing figure only.

For a turntable go here.

Modeling Techniques:

RapidWorks, Body

A great tool I used a lot was sew boundary, it fixed a lot of the Zfighting.  Healing Wizard also helped me identify which parts of my model had issues, not everything was fixed by the wizard, most of the time it was an assistance tool.  Isolating the problems that were identified with the healing tool made it easier to clean the mesh.

Standing Figure 

Before Alignment, 16M polys

Here you can see the color variation for each layer that became a clutter of massive problems.  A whole lot of messed up geometry and misalignment issues.  I also had an issue with the texture not following through to RapidWorks as well, but that was the least of my issues.

After Alignment, 26.85M polys

By the way, aligning took 6 hours with Rewrap.  The solution to reducing time, smooth = fewer polys.  I used three different methods:  Mesh Buildup Wizard, Rewrap, Optimize Mesh.  Optimize mesh never worked, it was an absolute 100% waste of my time.  From 1pm to 10pm the computer did nothing but "load," at one point the computer was running at 92% memory capacity due to this tool.  In my case, the wizard helped tremendously while the rewrap helped fix some of the overlapping geometry.  However, I still had to go in and delete a lot of the manifold edges and overlapping geometry because they made the model mucky like chunky peanut butter.  Some areas such as the buttocks and the legs were so destroyed by the manifold faces that I needed to rebuild a lot of the modeling with the sandpaper tool by hand.

One of many massive issues that came with Rewrap (after Global Remesh retopologizing) and decimate is that a large chunk of the normals flipped.  I am using the bridge tool here.  Take note of the massively broken boundary (aka squiggly yellow line on the back of the head).  Most of the model looked like this.  The horns were destroyed entirely from underneath.  The face lost a lot of the modeling from the nostrils to the neckline under the chin.  The gap underneath the udder to the pelvis was nonexistent and contained a boundary that went from the hand all the way down to the knee.  All the effort I put into making a unique stand also went to waste, now it's mostly flat.  A large chunk of that boundary was created from one of my partial scans from ScanStuido. (Later, I had to rebuild the stand in Mudbox just because RapidWorks didn't create a nice smooth mesh).

IMPORTANT INFORMATION: If you're trying to fill holes in ScanStudio and have an issue with the model being too large for the view window and think that you'll just fill the gaps with partial scan data, don't do it. It's best to not do close up scans of the object that are only partially aligned.  Make the decision to fit the entire object within the window or pick another scanning software.  If you can't make a fully attached scan discard it, otherwise you'll end up with a lot of massive broken boundaries in Rapidworks when trying to fill holes. Or unattached scan data.  The reason I chose to make only partial scans is that I couldn't get the torso to fit in the view window, so I let the scanner do what it needed to do and moved on with the data that I had.  Because I had about 1/3 of the torso scanned, the other 2/3rds were broken.  The location where the extra scan data overlapped with the original mesh caused a lot of flipped normals and massive gaps in geometry.  The tools in Rapidworks that try to remap or retopologize the sliced date sew pieces that you might not want to be sewn together creating a lot of problems later.

PARTIALLY ATTACHED SCAN DATA IS BAD!!
Scans B, C, and D were only sections of data, which basically corrupted my geometry.

 

This is the best example of what I'm talking about. (Ignore the massive wall on the backside of the figure, that was something that came about from using the wrong setting in a tool.)  The left thigh has a massive flipped normal, that is not a hole.  There are two layers of data on this model.  The legs had a more clean set of geometry, and the geometry underneath caused a lot of that messy, jagged noise.  This was a nightmare to repair.  Also if you go back to the image that I posted above with 26M polys, you can see the floating geometry that caused a seam from from the pelvic region all the way to the tip of the ear.  Most of it was deleted.  The hands were never fixed entirely in Rapidworks.

Mudbox, Body
I imported the body .obj file into Mudbox. Before you go any futher make sure you hold "spacebar" and select the arrows to change the position and scale of the object.  The importing process into Mudbox is dumb and the models are always scaled wrong.  When I imported the models, there were a few errors such as High-valence vertex, Two-sided faces, Zero-length edges, Degenerated Face. The best thing to do to correct these:

1. Make sure you're in triangular topology (quads don't work, *go here for more info)
2. Press "V" (goes into selection mode.)
3. Select all of the faces surrounding the error.  
4. Delete. 
5. Then use Mesh --> Patch.
6. Undo and redo the process until this works.

 Holes

I had run into a stopping point for the week of February 19-25th because of a significant error that has prevented me from continuing.  Sometimes on 22nd, I noticed I had a hole in my mesh post-quad topology.  Some reason Mudbox doesn't like editing errors in this topology type, so I imported the file into Rhino to clean the holes and discovered there's a vertex alteration in the .obj conversion.  The data becomes 4x larger when importing from Rhino to Mudbox.  The file never loads in Mudbox, unfortunately.  Professor Scott said to ignore the holes till I need to work in Rhino officially.   The Feb 23- Mar 3rd I was busy cleaning up the butter mesh on the body.

* March 5th, I discovered the solution to this hole problem and it was much easier to fix than I had thought previously. Use the Freeze tool to mask the holes (to prevent tearing in the mesh) then use the Remesh tool under Mesh --> Remesh, similar to Smooth --> Decimate in Rapidworks.  It asks for a percentage and poly count.  Just type in the poly count and it retriangulates the model.  Then you can go back and select all the polys around the hole with the "F" key and select mesh --> patch.

 Goat progression

The feet progression.

Because the feet were made on the base, the scanner didn't really like it much.  So I had to rebuild the feet twice.  Once in Rapidworks and again in Mudbox.  Nothing different was involved with Mudbox, I used all the same tools as the rest of the body.
 

Sitting Figure:

Import from ScanStuido

Udder mess

Scan Studio, Sitting

This part of the figure is the sitting portion of the process.  I did not run into any significant issues with this part.  The figure fit perfectly centered in the view port, and I only needed to do 2 scans, a top, and a side scan.  I aligned them with minor errors.

Before cleaning

Bridging the hoof

RapidWorks, Sitting

I first I fixed the viewport alignment with tools --> align --> Datum and changed the right image to match my view window for the front.
Then I used Mesh Buildup Wizard to attach all my scans from scanStuido to make a workable mesh.  The main problem is that the dew claws and the forward section of the hoof were misaligned similar to the standing figure, so I spent most of my time in RapidWorks cleaning up those areas.

Cleaned version 1

I had a few crazy boundaries that required some finesse.  Like I mentioned before the areas around the hooves were the worst.  I had to destroy most of the exterior mesh to rebuild it with the fill holes tool, golf and bridge were most useful.  I don't much like plateau much because it doesn't really know which part of the mesh to destroy; sometimes it erases the entire mesh.

The groin area was not possible to fix in RapidWorks.  I had to adjust in Mudbox.  There was a lot of non-manifold edges there, and I did the same as the hooves.  Used bridge and golf to remake the modeling of the legs and the teets.  The legs are folded over one another in this location and because there isn't a "pinch" tool like Mudbox/Zbrush.  In this program, you have to trick the mesh by building and destroying the mesh over and over till you get the right elevation for the geometry.


Mudbox, Sitting
The udders, the modeling around the buttocks and ankles, the creases, and the hooves were lost in the scan.  Same as the body and the arm I used the smooth, bulge, and knife tools. 

Cleaned version 2

Arm:

Mudbox Cleaned

Because all the issues I had with the standing figure I needed to create a new arm.  The mesh for the arm was fused to the udder, and I need to create a part that could be separated from the rest of the mesh for when the goat is sitting.  The standing figure is holding their udder while the sitting figure is not.

Scan Studio, Arm

Only one full 360 revolution scan was required for this model. I used 6 photos to complete the scan due to its simplicity.  It's just an arm.

RapidWorks, Arm

Same as the last two meshes, I first uploaded the scanStudio file then used mesh buildup wizard to attach all my scan data.  The bottom had a hole, and it was patched with bridge and golf.

Mudbox, Arm
Imported to Mudbox where the smooth, bulge, flatten, and knife tools were used significantly.

Rhino, All
I imported all the models into one file and manipulated them to begin my cutting.  I put all object on the origin by using Move and typed 0,0 in the toolbar.  Then used the various perspectives to position each object to intersect its corresponding geometry that I want to cut.

At this point, I wanted to see how the geometry matched up so I can go back and forth on Mudbox & Rhino.  Before and after, I wanted to bulk up the appendages. I made a minor error when creating the extra arm, so thats the last thing I need to fix before I cut all the geometry for 3d printing.

Problems:
This project was much more ambitious than I thought.  I am seeing that the descrepancies between the scan and the next stage in Mudbox/Maya/Rhino is a significant amount of repair and remodeling time.  Because Rapidworks doesn't have much for modeling a lot of gemoetry is lost when repairing the alignment problems.  I spent several hours just working in Mudbox which I didn't expect was going to happen.

The hardest part for this project is correcting my own bad geometry.