Intro: Yokai Mask From Big Hero 6
To make a part that is ready to print on a 3D printer, there are many different approaches. Most depend on what the final product is to be. For this Instructable I wanted to show some basic steps. I use an old version of SolidWorks that I've had for several years but there are quite a few different 3D CAD systems that are currently available. I'm a little more used to this than some of these others, so I continue to use it.
With many parts, the dimensions can be very critical, on something like this Kabuki mask that I modeled to resemble the Character Yokai from one of Disney's latest films, the dimensions are generally a little less critical. With SolidWorks, at the end of the project, it can all be scaled in all three directions together or each of the three (X, Y, and Z) independently.
To start with, on a project like this, I find some .jpeg images of the basis for my model and try to get as many angles and views as possible. Once I have those images, I begin to create my own drawings. With this movie being as new as it is, I haven't been able to get very many views of the mask that I want to model but it is a pretty simple mask overall so I felt comfortable to proceed.
Step 1: Extrapolate Some Basic Geometry
Once I have the images that I want to base my model off of, I use a vector graphics program to outline the image and get some basic outlines of the most important features for the part. I use CorelDraw for my vector graphics. Again there are newer programs with better features but I have been sticking with what I know. I take that basic geometry in the vector drawing program and I export it as 2D line art that SolidWorks can import. I usually use a .dxf format for this step.
I import the geometry into SolidWorks and use that to start building the part. In the part building steps there are many different approaches to get to the desired end result. Some of the features that I use in SolidWorks may also not be available in other CAD programs or they may call them something different. As you get to know the software you use, you are able to translate my steps and see if they are of use to you.
In building the part I use the geometry that I created with the vector software as my original, base drawing. SolidWorks allows me to make this drawing visible or invisible whenever I need throughout the process. This can help me in keeping everything straight in my mind.
Step 2: Build the Mask Base
My first step in my build was to Extrude a base that matches the outline of the mask. Because my basic geometry was a little crude I then created an aesthetic centerline on this base and cut the lefthand side of the part off. Next I projected a mirror image of that cut across that centerline to then get a full width part again. I do this from the beginning on a part like this so that I don't have to create all of the features twice, I just have to mirror them across that same centerline through the whole process. There are times that I want it to look more organic and in those cases I skip over this. On this mask everything is the same from left to right.
From that base I did what SolidWorks calls a Revolved Extrusion and came out with a round feature that matches the outline of the mask. In looking back at my .jpeg images the completely round feature didn't look quite right so I used the Scale feature. With this I only scaled it in the front to back direction and left the up and down direction and right to left direction as they were. This looked a little more appropriate to what I see in the images.
Step 3: Create the Nose
The first feature I put on my mask was the nose to match the mask. I created the sketch for the nose on the flat back of the mask. I matched the outline to the original geometry and mirrored it across the centerline of the part. Once I had the nose outline drawn, I extruded the nose and used what is called Offset From Surface with the Translate Surface option selected. This pushes the nose up from the flat surface and makes it follow the same contours.
Once the nose is created I blend it in to the rest of the mask using a Fillet feature. This takes the straight edges of the nose and rounds them off. This is all about the looks.
Step 4: Add All the Remaining Features
Just like with the nose, all of the rest of the features are created from the flat, back surface and Extruded out above the top surface of the mask. I sometimes try to do all of the features at once. Sometimes I find myself making one step forward and two steps back with this. What I generally come back to is creating one feature at a time and making sure that all the geometry works well. The errors that come up can be very time consuming to fix. The more geometry there is in each drawing, the longer it takes to find the errors.
Remember to save often all along this, as well. It can get frustrating to make significant progress only to lose it all to some glitch.
With all the rest of the features created I try to blend them all with fillets, too. These less prominent features I plan on using more as a guide for paint detailing after I print the mask so blending them isn't as critical.
Step 5: Turning the Block Into a Mask
SolidWorks has a feature that would be great for this next step and that is the Shell feature. It allows you to choose which surfaces you want to remove and then creates a uniform thickness for the whole mask. When I tried to use this, though, there were quite a few problems based on the fact that I couldn't get everything blended and smoothed out. Some of the uniform walls ended up missing.
Because of the errors using the Shell option I went back and cut the back out of the mask one small piece at a time. I cut from the back and did an offset cut instead of an offset extrusion.
Step 6: Cut Eye Holes
With the mask features drawn and prepared and the back side hollowed out to make this into a mask, the last feature to place are the eyes. From the back, the eyes are drawn and then cut through from the back to the front.
One other thing that can be done is to select and color individual surfaces to verify that the finished part is close to the original images.
After the mask is ready, the last step is to export the file to an STL file format to be used with a 3D printer. Most CAD software will export to the STL files that can be used with 3D printers. They can be adjusted in final size depending on whether you want to use it on an adult or a child.
With that you should be all set with a Yokai Kabuki Mask.