Parametric history is a fantastic new feature — which can be confusing! As you’ve noticed, sketches and bodies are connected, and deleting a sketch will remove its associated body, PLUS everything subsequently derived from that operation. The simplest cure is to Undo the delete and everything will return to its prior state.
The Fix command is named completely accurately – and is even more confusing. Fix appears in one or more steps in the history list when that step can no longer be completed. The History is just a list of operations you have performed where each individual operation is basically DO something TO something.
For example, often your very first operation is (DO) extrude (TO) a plane surface from a sketch. If you remove the sketch, the extrude operation no longer knows what surface you want it to extrude. When you press the Fix button, you are asked to select WHAT you want to extrude. Shapr3D will even give you an orange colored Hint as to what the original object was, but you can pick something else if you want. Or, if you really don’t need that particular body any more, you can delete the extrude step from the history list.
However, as I said, one change might result in a LOT of Fixes appearing in the history list because so many operations can build off some prior body. But fixing the original will often fix them all. I’ve found this to be very useful in woodworking, when, for example, the size of a bunch of drawers is related to the location of a particular frame member and I need to change the construction method towards the end of the design.
Note: there will often be multiple dependancies in one operation, e.g. mirror planes, rotation axes, etc. but the general principle is always the same. Whatever information Shapr needed when you first did the operation will need to be replaced / restored to Fix the problem.
As I said, confusing at first, but the more you learn, the more powerful (and indispensable) it becomes. I really like being able to Direct Model the sketches now, in addition to DMing the bodies like we’ve always been able to do. The ability to use sketch constraints on some dimensions while leaving others free to move allows me to make adjustments without breaking things.
), it can be disconcerting or even disastrous for anyone who doesn’t realize what is about to happen. Possibly, the warning could be optional and user configurable, but considering the very few instances where deleting a sketch is useful and the potential consequences of a mistake, it is probably best to always give a warning whenever someone tries to delete a sketch which has been “used”. Unused sketches (i.e. no associated body has been yet created or modified) could be deleted without delay.
A search on “history” came up with a number of interesting articles. There are many more, here are a few:
