The most important part about this work for me was retaining the original atmosphere and look of the sketch. Blender’s “Grease Pencil” tool helped me a lot to transfer that feel onto the 3D model. Since the original artwork was a totally freehand doodle and not considered for 3D, some changes were unavoidable, so I worked on those changes together with the artist.
I find this tool very useful by drawing over the models surface. Strokes don’t look perfect and little inaccuracy brings more of a freehand feel to it (and you can convert it to bezier curve and refine details).
The next trick was cartoonish outline effect. To get this I used an oldschool method – duplicate mesh, flip all normals and push it out little bit, the “Fishbird” was also done with this technique. This is not the most efficient technique for polycount, but it makes it easier to render on Sketchfab.
Texturing is the important part. It’s imperative to make the unwrapping process as intuitive as you can. I never use “relaxed” unwraps, because of distortion. When you’re painting in external software (photoshop for example), actual texture is stretching and then is very difficult to get perfect matching. I put little white and black boxes in texture, so I could scale down and fit all solid color elements in it, rather than use another materials for them.
Next and hardest part of this project was the animation, because of two reasons. First, this was my first animation in Blender and second one – publishing on Sketchfab. Fishes were animated with traditional technique. Using “follow path” constraint for perfect looping and tail waving with bones.
Tear drop animation is done completely with transform keys (position, rotation, scale). There are 5 elements: falling tear, first round wave, ejected water with small water drop and final round wave. I think this is best method for water drop simulation, because Sketchfab supports only transform and bone animations.
The waves, spreading from the boat also were animated with transform keys. They are gradually growing and hiding behind the water surface.
After quick researching and testing, I found that Sketchfab supports uploading *.BLEND file directly. Animations and parent-linking hierarchies remains the same. If you’re working in Blender, I recommend to upload projects in blend format, instead of FBX. Also I read about Sketchfab plugin, but I’ve not tested yet. Materials in Sketchfab was very simple for this project, shadeless preset with only one map. No lighting, no environment.