Having Trouble Sculpting with Precision

So, recently I decided to make a game on iOS using Swift, and I decided that I was going to use Blender to make the objects that I couldn’t just make from SceneKit’s default library. So, for the menus I was planning on doing something that looks good in 3D to add a little bit of flair, rather than just having it be flat and empty.

That being said, I’m super new to using Blender in general, and I haven’t really found a tutorial that had anything really helpful to say to solve my problem. At least, I don’t think I have. Feel free to suggest one if you know of one.

So, I was planning on making something look like a wood block, cut in a specific way. The game’s premise is getting a ball into the goal, so I wanted to go for a sort of machine-crafted wooden thing, with a small dip to hold a ball, and a path for it to roll down, like so:

I hope it does well to get the concept across, despite my atrocious technical drawing skills. I’ve just been having some trouble trying to find the proper word to describe what I’m looking to do, but it just escapes me.

I start out with a grid, and try to use the SculptDraw tool to make the dips. Afterward, to get the clean-cut corner I was looking for, I tried to use the Crease tool, which hasn’t been working out for me… I usually end up with either something that looks like a crater, or something that (for some reason) smooths out the corner, rather than makes it sharper. I’ve tried increasing the number of divisions on the grid, which has helped a little, but I’m still having a lot of trouble making it look right.

What do you guys think? Am I just looking past a tool that could help me? Or am I going about this the wrong way altogether?

Possibly. Might be better to carve the forms on a surface with boolean. If you do that, they work best with manifold geometry: closed pipe out of a cube, not open pipe out of a plane. Bool Tool addon helps to manage the boolean modifiers.

Since everything else is flat, only need to do a bit of clean up afterwards. Splitting concave polygons, and having clean triangulation.