Some progress on the boat hull rusting away sequence. I hand-painted mask keyframes that denote where rust forms and where deterioration starts to happen. Black on the mask is solid, black to 50% gray is rust forming, and 50% gray to white is where deterioration occurs. There are 8 keyframes in total. The result is getting there, but I still would like to do a bit of tweaking. Some of the keyframes towards the end jump a bit too much from one step to the next. 

This week I focused on developing this shader-based rusting/deterioration transition (23+ hours.) I had attempted a few different methods for making this happen. I originally was working with two separate masks to make this transition happen - one large detail control map (the overall, top to bottom rusting of the boat, holes, etc.) and one small detail control map (the ribbing of the boat.) This method I was first going with allowed for a lot of versatility in the timing of the transition and the blending, since it was all blended together in the shader, but finding a way to blend them together well in the material turned out to be probably too much overhead without necessity to get the visual result I needed. Painting all of these details in one mask and separating them by value seemed to allow for a more natural, organic blending across the whole boat.