3D Snowflakes [From Microscope Pictures]

When it comes to christmas and winter time, I can think nothing but snow as a source of inspiration for my creations: I find it so elegant, charming and relaxing; it just puts me in right mood when finally it starts to drop.

Moreover, I'm incredibly fascinated by the beautiful and unique structure of snowflakes, so I decided to recreate one with 3D Printing as submission for this competition.

While looking around for inspirations, I came across the astonishing pictures of Kenneth G. Libbrecht, professor of Physics and Chairman of the Physics Department at Caltech University: he captured snow crystals that fell to earth in Northern Ontario, Alaska, Vermont, the Michigan Upper Peninsula, and the Sierra Nevada mountains of California using a specially designed photomicroscope.

I was amazed and I thought I could transform those incredible pictures into 3D files, and bring the snowflakes back to life (Scaled up) thanks to 3D Printing technology.

I then contacted professor Libbrecht, he was very entusiast about the idea and decided to share high resolution images with me for this project. Thank you professor!

My submission is a Christmas tree decoration made of 3 snow flakes balls, one inside the other, derived from 3 different snow flakes photomicroscope pictures.

I'll describe now how I got to this result, and how you can do the same with your 3D software (I'm indeed describing the process, and not the specific steps inside the softwares, as these may vary).

This object is designed to be 3D printed through Selective Laser Sintering technology (SLS) or Fused Deposition Modeling with dissolvable support material (Better SLS since it results in a way better surface quality), since any other type of support will be very hard to remove from the object's interior.

You can also find and print my model (In polyamide material, through SLS printing) at this link:

http://www.sculpteo.com/en/print/snowflakes_balls/...

SnowFlakes_Balls.stl
Download

Step 1: Choose Your Reference Images

The first step to obtain a model like mine, is to find the right source images to use.

I went through the wide collection of snow flake microscope pictures that professor Libbrecht shared with me, and I choosed 3 of them. Doing so, I took into consideration, beside the aesthetics, the solidity of the resulting printed object (SLS technology requires a minimum wall thickness of 1 mm).

These pictures show real snow crystals and they were captured by Kenneth G. Libbrecht using a specially designed snowflake photomicroscope.

Step 2: Convert Your Images to Greyscale

In order to later be able to extract a 3D shape from the images you've choosen (Through a technique called 'Displacement Mapping'), it's better to turn them to greyscale first.

The 3D software that you are going to use in the next step, in fact, will read the white areas of the images as 'reliefs'. At this stage you should aim to obtain the smoother transition possible between dark and lighted areas in your picture, in order to produce better results within the 3D file.

This operation can be done with any image editing software like Photoshop, Gimp or Paint.

Step 3: Displacement Mapping

The technique that I've used to transform the pictures of real snow flakes into digital 3D models is called "Displacement Mapping", and can be performed by several 3D modeling softwares, like Mudbox, Zbrush, Maya, 3DS Max and more.

The greyscale images previously created are applied to a 3D shape (In my a case, a plane): the sofware will bump up the white areas of the images, creating a 3D relief.

The range between the highest and lowest point of the bump, can normally be specified by the user;

I kept it around 1 mm in order to make the details well visible on the 3D print.

Step 4: Thickening

Having exported you geometry just generated through displacement mapping, you will now have to remove unwanted parts, deleting some polygons from your model.

Then you will need to add a thickness to your model in order to make it printable. The way i created this thickness is mirroring my surfaces and connecting them , to create a solid object.

In this way, details of my snow flakes are simmetric and visible on both sides of the object.

Take in consideration once again that the model need to have a certain minimum thickness in order to be printable, normally around 1 mm. Also, saving or material amount, helps in reducing printing costs.

The 3D flakes at this stage are already 3D printable (although separately) as Christmas ornaments, and you can find them here:

http://www.sculpteo.com/en/print/snowflake_flat_1/...

http://www.sculpteo.com/en/print/snowflake_flat_2/...

http://www.sculpteo.com/en/print/snowflake_flat_3/...

Step 5: Create Spheric Shapes

Now that we have the 3D models of the snowflakes, we want them to be spherical in order to create the ornament.

The way I did this is through a "bending" operation, in which the flat shape gets "moulded" on a semisphere.

Then the resulted shape gets mirrored to obtain the other half and complete the sphere.

Don't forget to then merge these two parts through a "Boolean" operation (Fusing the two shapes into one).

See and print this model at these links:

http://www.sculpteo.com/en/print/snowflake_ball_1/...

http://www.sculpteo.com/en/print/snowflake_ball_2/...

http://www.sculpteo.com/en/print/snowflake_ball_3/...

Step 6: Merge and Export

Once we have these 3 spheres, derived from microscope pictures of real snowflakes, we can position them one inside the other and merge them to obtain just one object (Made of 3 shells).

This type of "Russian doll" type of configuration is specifically manufacturable only through 3D printing, but keep in mind that a certain space (Normally called 'clearance') needs to be preserved between the surfaces in order to don't make them fusing together during the production process. Clearance required in SLS technology is normally around 0.5 mm.

Finally I added a small ring on the top in order to make the object easily hangable.

Export the file as an .stl and it's ready to be 3D printed !