Direct vs Parametric

00:00

In this video, we're going to talk about the differences between direct modeling and history-based parametric modeling in the solid modeling environment inside of Shapr3D. So you can see here we have this cylinder that we created in a previous video. Not terribly complicated. We have a few items on the left hand side in our items panel and a few in our history. And we're going to hide the history panel for right now and just talk about direct modeling. So in Shapr3D, direct modeling is...

00:30

our ability to select individual surfaces and be able to modify them directly without having to use any particular feature. Shapr3D is really good at exposing individual features that we can use just by selecting on certain surfaces and doing different operations based on what we're selecting. The other thing that Shapr3D does really well is that it gives us...

00:56

dimensions that are based on the model as is. So as opposed to just giving us some regular offset, it actually is giving us the entire height of that cylinder for us. So it does retain some information in the model itself. The other thing that we can do in direct modeling is we can edit our previous sketches and those sketches stay connected to our model. So if I wanted to, for example, change the diameter,

01:23

of the cylinder, you'll see that the cylinder also updates relating to that sketch. So that's something that is built into the direct modeling environment in Shapr3D. So right now I'm just going to take some adjustments on these. I'm going to make this seven millimeters. I can stay really precise in the direct modeling environment by being able to select these elements. I'm going to make this dimension here 18 millimeters, which is great.

01:50

And you can see that my cylinder here is updating as well.

01:56

I'd also like to update the extrusion that we have here. So I'm going to select this bottom surface right here. And I'm just going to make this 18 millimeters. So very quickly in the direct modeling environment, we can adjust those parameters and build elements very quickly. In Shapr3D, we also have a history-based parametric model. So if I come over here, I can already see a history that's being automatically populated.

02:25

You don't have to use this panel if you're not interested in being able to control these elements. But you can see that every time that we made some kind of movement, we had a new feature added to our history tree. So if I click on any one of these history trees elements, I will see what happened on that particular step. And I can also open that and adjust various parts of that individual card that pops up in the history tree. In this case, because we had just directly modeled.

02:54

adjustments to this cylinder, we're getting offsets that are being added to our history tree. If I'm using parametric modeling, I would prefer not to have these offsets inside of my history tree because it tends to clutter that up. So what I can do is I can just delete these elements.

03:14

I can just go back to a previous feature and adjust that overall height. So I'm going to open up this card and I'm going to adjust this section here and just say, I want to make this minus 18. So that is an effective way of using the history based parametric modeling and to keep our history clean overall without having to have a lot of like little tiny movements in there. So those are two different methods of working. I.

03:43

kind of go back and forth. So as I'm building something, I might, you know, do a bunch of offsets. I might see that there's certain features that I can add or subtract. I can go back into the History panel and see if I can include some of those movements that I made into other steps so I can clean up this overall history. So as an example, I'm going to directly model a new extrusion. So I'm just going to shift click these.

04:10

areas here in my surface and I'm going to just extrude a new section. I want to just make this two millimeters and this outer cylinder here is being driven by the sketch so if I wanted to adjust it I could just go back into my sketch here and adjust the overall dimensions here. But this is good enough for now I just wanted to do a quick extrude here of a couple millimeters and what you can see is that we have a new extrusion that's listed here. So I can go back

04:40

the direct modeling and the history-based modeling to make my workflow a lot faster. One of the things that the history-based parametric modeling helps me do is it allows me to update elements inside of the history out of order. So for example, if I wanted to adjust this extrusion, I could change this extrusion value here and the entire model will update afterwards. The other thing I can do is I can change the order of the individual

05:09

components. So if I wanted to, for example, reference some other thing, or I wanted to be able to change which order individual elements are rendered, I can just change their order in the in the history panel. The other thing I can do is I can also suppress individual features. So as opposed to trying to delete something or move it out of the way, what I can do is come in here and I can click on the suppress button and the suppress button just

05:36

removes this individual item here. So you can see that we have an error now because of that extrusion. And the reason is that this was referencing the very top of that cylinder. So we'll have issues like that that will pop up that we'll need to take care of in order to successfully suppress or delete an individual feature. So I'm going to just unsuppress this now.

05:59

The other thing I can do is what's called add a breakpoint. So if I go into my history tree here, I can select the three dots. I can click insert breakpoint. And what that does is essentially suppress the history of the model after the breakpoint. So I can use that to insert new features into the design overall. So for example, if I wanted to bring this sketch back, I can add a feature here that's before.

06:27

the previous elements that I've made already. So let's say I wanted to make, you know, some kind of tapered section here. I could add this in here, I could add my dimensions as I like. And then when I delete the breakpoint, you'll see that everything rebuilds after that point. So this extrusion here is built before these other elements here, which were behind the breakpoint.

06:56

At this point, we've covered a lot of the differences between direct modeling and history-based parametric modeling. In the next video, we're going to take a look at how we can add more sketches to create more complex features and use constraints to better define how those sketches interact in the model.