First time cosplayer & novice 3d designer, couldn't find much online to help put together my Eldar Dark Reaper armour & really struggled with soul gems/ armour decoration specifically. It was so hard to find something to create the shape.
So, I fooled around till I came up with this. I'm sure someone can do a better job but I thought this might help someone else since I struggled to find much.
The original size is 80x150x25mm, with 4 walls & tree supports however I have also added plates for 50% - 120% at 10% increments, with the actual size included in the plate name.
Hope it's useful for you