Oh c'mon this is a request section. I need to work on project, why some good modeler can't waste 2 mins on this simple edit? I already wasted 2 days trying to do that myself.
Give a man a fish and he will eat for a day. Teach him how to fish and he will eat for a lifetime.
Here is how to set the visibility of a geoset:
1. Open the model in Model Editor.
2. Go to Windows -> Sequence Manager and open the first animation on the list.
3. Open Notepad (or take a piece of paper) and write down (or copy n paste) the starting frame. For example the attack animation has an interval from 18000 to 19000, so you write down 18000.
4. Do the same thing for all animations.
5. In the Model Editor, hold Ctrl and click on the lumber geoset. It should turn black for a second.
6. Now go to Windows -> Geoset Manager and you'll see which geoset is the one you selected with ctrl+click. Remember it's name (or position) in the Geoset Manager.
7. Go to Windows -> Geoset Animation Manager. Create a new geoset animation (Right click -> Create New).
8. Tick the little box to make the geoset have animated alpha.
9. Then click below that box where it says Alpha.
10. Now enter the starting frames of all animations in order (from smallest to largest). It should look something like this, but with different values:
300: 1
1600: 1
2900: 1
5867: 0
7000: 1
8300: 1
12567: 1
72867: 1
75500: 0
135800: 0
142700: 0
0 means the geoset is invisible during that animation
1 means the geoset is visible during that animation
However, if you used Matrix Eater before this, maybe it has already created a geoset animation that refers to the lumber geoset, so you only have to find the geoset animation and edit the visibility, instead of creating a new one. Go to Windows -> Animation Controller to see what geoset is visible in each animation.