This week
During previous week and this week's first half I was primarily working on visuals. This includes rework of Red Alert inspired slower towers, new models for upgraded towers and more.
Glowing Towers
One of the visual effects I implemented is glowing towers. This feature is very apparent in slower towers, but some of you might notice that other towers make use of this effect as well (the little lights at the bottom of the towers). The player will now also have a visual cue about the current upgrade level of the tower. If the level is 1, the tower will glow in yellow, if level 2, the tower will grow in blue, if level 3 the tower will glow in red/violet.
Normal Maps
I also started implementing normal maps into my game. As of now the most apparent tower which uses them is the slower tower. To generate the maps I used the free online tool which does a pretty good job and I think it will be sufficient for now. This is the result:
Next Week
For the next week I should be going through and implementing features in my TODO list which includes functionalities such as CTRL+Z to undo tower placement, fix the issue where towers expand infinitely, add jet fighters which drop bombs on turrets, and more.
Nice job on the glow! I really like it.
For normal maps I would strongly recommend using xNormal as a free option http://www.xnormal.net/
I personally bake in Substance.