"ticking" all sub-keywords by "ticking" parent keyword

I was looking for the same answer, and digging around a bit, I found out how to do it, so here goes:

You have to make a keyword tree instead of placing all sub keywords in one group at the same level. So, to use your example, instead of making a group called "footage" with a set of keywords at one level below it, you do a parent keyword "footage", than create the sub keyword "3d rendering". Then make “animation” a sub keyword of "3d rendering", and “closeup” a sub keyword of animation, and so on, so you get a series of sub keywords at an increasingly deeper level instead of just all keywords in a group at the same level.

Then in Bridge go to Edit->Preferences->Keywords, select "Automatically Apply Parent Keywords”. If you then select the keyword group "Footage", and click at the bottom level sub keyword “spin", that will apply all keywords up to the top level “footage” to the image file. If you only want to apply one of the keywords in the tree, select it by shift-clicking. If you select the whole tree by mistake, shift-click the bottom level keyword to deselect the whole tree, and then select the individual keywords that you need by shift-clicking them. Alternativelty, if you select the whole tree, you can just click again on the keywords you don’t need to deselect them.

Hope this is clear.