Well yeah, I noticed it said that in the book too, so I did that, but it still doesn't seem to be doing anything.
So as you can see here, this is the original image.
Then I tried two things; The first being just erasing the top grass pieces for the collision mask (as you can see here):
That didn't work, so then I even tried cropping the top portion off, and it still didn't work:
So I'm still unsure...
As for the book, it's really good so far. I'm only on page 77 so hopefully it starts to get into a good bit more detail as I still have unanswered questions in my head.
For example, I've only made a small sample game on a 1000 x 800 frame so far obviously, but for games like Metal Slug or Contra that have lonnnggg levels that go on and on, are they using a gigantic layout like 12,000 x 800 to stretch for a very long time and setting up their level that way? or are they linking layouts together somehow...
So hopefully questions like that will get answered, but I'm highly enjoying the book so far.
One other thing I don't understand that I don't think the book will cover is using sprite sheets with Construct. To my understanding so far, sprite sheets don't work with Construct, so if I found a sprite sheet online that I wanted to use of a character for example. I would have to manually chop up all of the sprites needed for the various animations in Photoshop, and then load all the frames in, inside the animation window?