Have you more simple?

 From:  Michael Gibson
674.2 In reply to 674.1 
Hi Pilou,

Generally the fastest way for something like this is to draw it initially in that widened shape, instead of trying to edit one shape into a completely different shape.

There are other solid modeling programs like SolidWorks, etc.. which are more focused on doing that type of editing.

MoI is much more focused on drawing quickly rather than editing existing models into completely different shapes as much.

Of course it is still possible to edit a shape, you showed one good way to do it by boolean union. But it is so much faster to just draw it the way you want it from the beginning... In this case it looks like the grooves were cut by a boolean with a box and a cylinder - if you think that you will want to change the bottom shape I would recommend keeping these box and cylinder shapes around saved in a file somewhere, so you can later on redraw the base shape and then boolean out the grooves from it again. In a future version I want to add more history functionality to make it easier to allow this type of thing more automatically but for now you have to keep track of these older objects yourself.

The other editing method than boolean union is to separate the model into different surfaces and edit the surfaces, then join those surfaces back into a solid later. This object repair tutorial gives some details on this type of detailed object editing: http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17 . It takes a little bit of practice to get used to this type of editing.

Here is how I would apply that type of "low-level" surface editing to this situation.

First, just delete all the faces that are going to be changing, and extract (by copy/paste) the edges that you want to move:

Next, scale those extracted edges by scale1d. Then loft between those edges and the edges of the back face to get this:

Next, draw some lines to connect pieces in the front, then use Construct / Planar to build a surface there:

Then select all surface pieces, and use Edit/Join to glue them together. Then select the combined object, and use Construct / Planar to fill in all planar holes (there are 3 holes that get filled in here):

I'm not sure if that is actually quicker than your boolean version... I guess maybe it is faster because it handles both sides not just one side.. Anyway, I wanted to make sure to show it because this type of editing is very powerful, it will allow you to get into any object and make very detailed changes to it.

For shapes with a lot of planar faces, it helps speed things up if you try to form one closed ring and then use Construct / Planar to fill in all planar holes automatically like I did here - that can fill in a lot of stuff automatically if you just build up the side parts.

Hope this helps give some other ideas for object editing!

But again let me stress that it is better to keep the cutting objects, and just redraw the base part and repeat the boolean difference that created this object in the first place.

- Michael