Not size zero

So, Daz 3D have finally seen the light and changed their EULA to allow 3D printing of their models, but only for non-commercial use. It is a relief to be able to use the software and models legally now, but I still can't share any of the meshes or sell the models that I create.

As you will know, if you have read any of my previous posts, I enjoy the challenge of trying to create beautiful sculptures by posing a 3D model to match either an existing photograph or an image that I have in mind. One of the aspects I have spent less time on is adjusting the shape of the woman's body. I received a comment from a reader asking whether I ever sculpted larger women and I had to admit that I hadn't tried yet, so this time I thought I would deviate from the default, skinny model body shape and try creating a woman who looks more typically average in body size.

I used the Victoria 6 body with the HD mesh add-on, which has more natural curves around the joints. I began with an idea for a pose in a fairly relaxed style and then played around with all the different character shape parameters , giving a modest 20% increase to the 'Heavy' setting and a 70% boost to the 'Weight' parameter. I'm not entirely sure what the difference is but it's quite an interactive process, so I just move the sliders slowly and stop when I see the effect I'm looking for.

Daz haven't just given permission for 3D printing of their models, they've simplified the whole process too. Upgrading to the latest version of the Genesis 2 models brings a new option to the Anatomy section.

This rather gruesome-looking add-on modifies the geometry of the eyes and mouth, turning them into closed meshes. It also replaces the front of the eye with a new, more sculptural representation of the iris and pupil.

I chose an elegant, raised hairstyle that still required my previously-described shrink-wrap technique to make a fully printable model.

The pose would clearly need support material turned on in several areas, as can be seen in the print below.

This is quite a small print, taking five and a half hours to print at 0.1 mm resolution. There are still some small blemishes left after removal of the support material, particularly on the underside of the model. There are also signs of irregularity in the Z-direction which need further investigation.

Overall, a very satisfying project.

Lush

This beautiful photo of Kayleigh Lush was one of the 100 photos taken by Ray Rapkerg and published on Twitter.

It's another interesting and challenging pose and also presents a great opportunity for me to practice sculpting hair.

The fingers of the right hand only make light fingertip contact with the ground which would present a problem during printing, so I have added a thin disc to anchor the hand firmly and take the weight of the right forearm.

Here is another angle which gives a better view of the hair.

The model printed well at the first attempt but needed plenty of support material under the face and breasts.

Here is a selection of views after removing the support material and ending with a video showing the model from all sides.

The next picture and the video were taken in full sunlight which brings out the amazing sheen in the printed plastic. It's called Christmas Green PLA from 3D Filaprint.

The obligatory full rotation view video.

Shame

I'm going to try and create a sculpture based on this picture next. I like the off-balance lines, the hidden face and the twisted shape.

The photo is by Tomas Rucker and is called 3 in his White series of nudes.

Here's the model I have created so far, viewed in Blender. The pose is clearly not identical but you can see where it takes its inspiration from.

When I came back to work on this pose I wasn't happy with it. The sinuous nature of the original pose had almost completely gone and the new hand position somehow changed the story. I decided to do some more work on the posing.

Then I thought it might be interesting to document the steps needed to make a posed model printable.

Hide the hair
Remove the eyelashes

Circle select eyes and mouth in side view

Shift-H hides everything else. Trim out the eyes and mouth and close up the holes in the mesh.

Hair models in character posing software are almost always totally unprintable items. I have found that the quickest way to make them printable is to use the ShrinkWrap modifier on a dense Isosphere placed in a position surrounding the hair model. Then using the project option in a negative direction, you can send all the points of the sphere inwards until they meet some point on the hair, leaving you with a single water-tight mesh. Some fairly intense smoothing removes all the jagged edges and leaves a very passable, and printable, copy of your chosen hair design. 

This just needs Boolean merging with the head which usually works OK, as long as the eyes and mouth have been fixed first. 

Now we need to deal with overlapping limb parts. There are several ways of doing this.
1. The quick and dirty method.
Use Autodesk's Project Miller to re-skin the visible external surface which hides any internal overlaps.
2. Use sculpt mode to flatten overlaps from the inside.
3. Use Boolean union to eliminate the overlaps. This option is interesting but doesn't work on a single mesh with overlapping parts. So why not just chop up the parts into separate meshes? Worth exploring, I think.

I started at the feet and worked upwards, using option 2 to eliminate any of the areas where the mesh of one limb poked through another. There is a typical example where the thighs cross. I used Box select to highlight all the affected vertices and then Shift-H to hide everything else.

From the inside you can see the bulge of the left thigh poking through into the inside of the right thigh, and vice versa.

I started by changing from Edit mode to Sculpt mode and then using first the Flatten brush and then the Smooth brush on the bulge to make it disappear. 

By working from both sides I could keep the contact area flat.

This works well where there is a small bulge across a large area, but is less effective where a larger, more complex part needs removing. So for the intersection of the arms and the left breast I decided to try a different tack and used option 3.

I rotated the model by 35 degrees around the vertical so that a horizontal plane would neatly bisect the upper arms. I then loaded the model into NetFabb which has a very nice plane cut function which provides a kind of X-ray preview of the slice before making the cut.

My cunning plan was to slice the model into a number of separate parts, make each one into a separate water-tight mesh and then Boolean merge them back together thus dealing with a number of complex overlaps at a stroke.

After making the cut, each half needed to be saved separately. The forearms, in the lower half, could then be selected and split off into a separate model. Here is the main torso piece.

My plan worked almost perfectly, only failing when the last piece in the sequence refused to Merge with the rest. I suspected that this was because the Boolean engine was struggling to cope with the intersecting parts and closing the loop of a torus and recognising the relative inside- and outside-ness of both ends at the same time. I fixed that by making another thin cut that took a slice out of the arms in an area with no complex intersections. Using that slice as the final merge then worked successfully. 

I added a simple bevelled cylinder to the base to make a stand. Eventually, I had reached the point where the only crossed meshes remaining were in both armpits. I spent a fairly lengthy mesh-editing session trying to clean up the mess but finally decided to take the easy way out and used Project Miller to re-skin the model for me. Don't know what I'd do without that bit of kit!

The main reason for going to all this trouble with the model was so that I could use Simplify3D as my slicer. Cura is better at handling faulty meshes but Simplify generates better support material that breaks cleanly away after printing.

I had intended to print this model on my tall delta printer, but it isn't coping well with this hot weather and the motors seem to be prone to skipping steps. So I went back to the Mendel90 and printed a small test version.

3D printed version in coffee-brown PLA before and after removing the support material.

Just like Pensive, one of my earliest works, the fingers are only slight wider than the extruded filament at this scale. It really needs to be printed twice as big as this. As soon as the cooler weather returns I'll try again on the delta printer.

Brenda Lynn

This photo of Brenda Lynn Acevedo, found on the Bella Donna blog, caught my eye for a couple reasons. Firstly, having her arms (and, in my imagination her legs) held either flat or vertically makes them easy to print without support; and then of course there is the way that her breasts gently rest on the floor giving them a profile that reminds me of a Piet Hein superegg (go and look it up and you'll see what I mean).

The fluid nature of (natural) breast tissue means that it naturally reshapes itself in response to gravity. (Of course, the same is true of all fatty tissue, but the models in these photos don't usually have much surplus fat in other places, so this issue generally only affects the breasts.) Character modelling software allows you to position the limbs, trunk and head in anatomically plausible positions, but also allows you to change the shape, size and position of the breasts. One thing that it doesn't do very well though is to model the impact of gravity on mobile breast tissue; there are add-on pieces of morphing software that give an additional level of control, but nothing I have found yet that mimics the effect of gravity on natural breasts in a reclining position.

So, after exporting the best pose I could manage from the posing software, I started sculpting in Blender until the breasts had a shape I was happier with and which I was ready to try printing. 

Feeling lazy, I used the clock rewind trick to bring Project Miller back to life again and quickly generated a single watertight mesh from the multi-object base and then did one more smoothing iteration.
I used Simplify3D for the slicing and made sure there was plenty of support material around the right arm so that the small point of elbow contact with the bed wasn't put at risk of failure.
I decided to use a nice wood-coloured PLA from 3D Filaprint and after a long 16 hour print this is what the printer produced.

Opinion: I'm generally very pleased with this one. There are couple of areas that could be improved - some distortion around the heel, and rather too little support material in the small of the back and between the shoulder blades.

Postscript: I decided to adjust the layer positions and try a reprint. This one came out even better.

Reflections

Here is the first of three new prints I have been working on recently.

'Reflections' came to my attention when Bruno Birkhofer posted a different picture on Google+ last week. All his pictures are beautiful but, once again, it was one of his black and white portraits that inspired me to try another sculpture.

Modelling the pose in my favourite character modelling program was fun, as usual, but it proved particularly tricky to place the hands in exactly the right position. Several of the joint movement ranges have to have their range limitations turned off just to get close. 

In a moment of over-zealous optimism I decided to replicate the model's facial expression and kept the eyes closed but the mouth open. This involved a significant amount of cleaning up in Blender for a detail that ultimately proved too small to show in the final print. 

Not to worry - one day I may be able to sell these models and perhaps I'll even be able to afford a nice high-resolution DLP printer like the Kudo3D and then they will look even better.

I'm now getting the hang of using Simplify3D to slice my models so that the support material is placed where it's needed. The only thing I got wrong this time was placing insufficient support underneath the ponytail. The tip broke free during printing but fortunately the print managed to correct itself leaving enough to look reasonably OK.

Here's a couple of photos of the final print using translucent coffee-coloured PLA from 3D Filaprint, at 0.1 mm layer resolution with support enabled.

Close-up reproducing the pose in Reflections

The full model, showing a nice reflection of its own

Arch

Pinterest continues to be a great source of inspiration for my 3D printed nude figurines. The latest photo I found was this one, which, according to Google image search, was originally taken by L M Hughes.

It's a fantastic pose and a great challenge for a 3D printer.
I set up the pose using my favourite software and then went through the cleaning process, which is now getting quicker as the routine becomes more established. These are the steps I now go through:

• Export the model as an OBJ file keeping the body and hair as separate objects
• Import the model into Blender - the hair and body should be separately selectable 
• Hide the hair temporarily
• Select the body and go into point edit mode
• Pick any vertex and then use Ctrl-L to select all linked vertices. Now press H to hide these points. This is a really easy way to identify any internal components
• Select all of the eyelashes,teeth, gums and tongue and delete them
• Keep the front of the eyes but delete the iris, lens and non-visible parts.
• Use Alt-H to un-hide any hidden vertices
• From the side view, select all the points in the bottom 1-2 mm of the model and scale to zero on the Z axis - this makes a flat base for the model
• Now in object mode, hide the body and un-hide the hair
• Add a high density icosphere mesh so that it surrounds the hair
• Shrink-wrap the sphere around the hair target using the negative projection setting so that all the points move towards the centre until they meet the hair surface
• Now delete the hair object and keep the sphere which has taken on the shape of the hair, but in a single closed mesh
• Un-hide the body and save the body and hair together as an STL file
• Open the STL file in Cura
• In the Expert settings, use FixHorrible-Type B - this removes any internal holes and prints much more reliably
• Turn on the default support settings
• Use Z-lift on retract to stop the nozzle from catching on edges as it travels from area to area
• I printed at 0.15 mm resolution with some fairly aggressive cooling from a new fan mounted on the hot-end

Here is the printed model with the support structure still attached.

And here it is with the support removed.

Even the top of the foot came out well thanks to some fairly aggressive cooling.

Kayleigh

One of the most beautiful poses I've seen recently on Pinterest was this one.

It had been repinned many times, so clearly other people agreed with me, but wasn't being properly credited. I used Google image search to track down the original version and discovered that the model is Kayleigh Lush.

I used my favourite character modelling software to emulate the pose (not exactly right, but good enough to capture the spirit of the picture, I hope) and then exported an OBJ file. I then used Blender to correct the orientation and scale and to flatten the base and remove the eyelashes, before exporting an STL file.

Here is the screen capture of the 3D model in Blender.

This time I used Project Miller again to select the external surfaces of the model, then used Kisslicer to generate the gcode file with full support turned on and printed in white PLA from Faberdashery at 0.15 mm resolution. 

Another pretty successful print, in my view.

With hindsight, it might have been better to have sliced with Cura and used the expert setting called 'Fix Horrible' - type B, which closes all internal holes and deals much more nicely with limb overlaps. Maybe next time.