Join Veejay Gahir for an in-depth discussion in this video Duplicating objects, part of Alias Essential Training.
- In this video we're gonna take at look at duplicating objects. This is a very important part of any CAD system, being able to salvage, duplicate, copy and paste entities very quickly to speed up your workflow. And I wanna show you some areas that you have to be a little bit careful with when you're doing this in Alias. So first of all, let's take a look at this data. This is just a piece of mesh data that I created in Maya and imported into Alias. And you can see that in Alias the mesh data is actually three sided, so it's a tri. Some CAD systems use four sided entities, which are quads, but in Alias we will be using tri's and that's what Alias prefers.
Okay, so let's select this data and the simplest way to copy this is simply Control C, Control V and then we're gonna go to Move. Standard Windows operations for Control Copy, Control Paste. So let's delete this. Now another thing we can do here is if we create a copy of this entity, Control C, I can go up to File > New, I can start a new session of Alias and if I say No this time it creates a brand new session of Alias. You'll notice down here in green, I've still got my old session open.
And now I can do Control V for paste and then I can go ahead and move this data like that. So I've actually got sessions of Alias open. And let's just move this up, like that so we can distinguish it very clearly. So this is my active session. I can go up to where it says "Stages" now, cuz it's created what we call a "stage". And I can select this active session or this one here. If I go up to Editor, you can see it allows me to jump between these two sessions. But I can still see in green my old session, or my other session that's active.
I can actually go ahead and switch that off. So what's here in yellow right now, this is my active session, so you can see I can use the window sources from either one of those sessions. I can use the background source but I can make this one invisible. If I switch to this one, this has to be visible obviously but I can make this one invisible now. So you can jump between sessions and you can copy and paste between sessions, which is a really great way to work. So in this case, I'm gonna select this entity again, Control C. I'm gonna jump into this session here and then Control V.
So you can jump between sessions and transfer entities very very quickly. So let's do this. Let's go back into the Editor, and in this case I'm gonna select my original session and then you can go to delete and you can say delete all stages or delete the selected stage. Well I wanna keep this one, so make sure I select this one here. And say delete selected stage and we'll say okay to that. So we're back to our original wire file. So let's go ahead and delete this piece of data.
And we're gonna be using the Edit > Duplicate > Object function quite a lot here so I wanna go ahead and setup my shelf. And I've moved my shelf up to the very top here. I've selected the Evaluate tab, in fact it doesn't really matter which tab you select. And into this tab I'm gonna go and drop Duplicate > Object like that. So it's easier to access. So double click this, now this is the reset or the default values. Everything is zero and on scaling we have a value of one, one, and one.
Now one thing to note here is that we've already covered reflecting across a center line, so if I change this value to -1, which is the Y and I say go to this. Alias actually asks you that you have to preselect the entity before you execute the command. Sometimes you have to preselect, sometimes you execute and then select. So it can get a little confusing but it's not a big deal. So let's go ahead pick the entity and let's go ahead and click that one time and it reflects across the center line. Now let's open this back up again and look at our options.
Now this is an instance. Now if I want an actual copy I need to select Copy. So let's go ahead and select this entity here. Delete this. Open this back up again. And we're gonna select Copy and we're gonna say go to that. Now this is a completely independent entity to this one here. So that's one way we can do that. Let's go back into Duplicate Object. Now here's something to note in Alias, if you do change the values of scaling and then you click on Reset, you'll notice it doesn't set it back to one.
You actually have to do this one manually. But if you change any of these values, let's say to 100 and then you click on reset, that will go back to zero. But now this one here has jumped back to -1 so let's go back to 1 on this one. Okay so another way we can do it is to rotate this entity 180 degrees. So we can go back to Rotation and we're rotating it around the Z axis. So let's type in 180. And we only want to make sure we have one copy and let's say go to that.
And again, there's our copy. Let's delete this entity. Let's select, open, we're still on Copy, we can actually go ahead and reset. And in this case we have to go back and manually do this. So this can be a little bit tricky just keep an eye on these values. So now we're gonna translate in the X, let's say 500. And we're gonna say go to that. And there's another copy that we've selected. And again this is independent so we can pick that up, we can move it, we can do whatever we want to do with this entity.
Let's go ahead and select the entity again, open up Duplicate, let's do a reset. Now in this case, I'm gonna translate into Z, 500 millimeters but this time I'm gonna create three copies. So let's say go to this. And if we look at our results, we actually have three copies. So the nice thing about this is Alias doesn't stack the three copies at 500 millimeters all on top of each other. Doesn't really make a lot of sense. So what it does, it staggers them. First it's 500, then 1000, and then 1500.
So just be aware that that's the result that you're gonna get if you want to create multiple copies. Let's Alt L, to zoom in on this. Let's double click, let's do a reset again. Again see reset doesn't set that so we have to go back in there and do it manually. Okay finally I wanna mention something about working with instances. So let's go ahead and select Instance now. And I'm gonna go ahead, again I need to preselect my data, open this up, we're gonna select Instance. And let's set this to zero.
And let's do just a simple reflection across the center line like that. Let's say go. Now in the world of CAD, an instance should follow what the parent geometry is doing. So if I select this parent geometry, and let's go to Non-proportional scaling, for example, and scaling the vertical like this. The instance should follow suit. Well it doesn't in this case. So let's Control Z that. Let's go ahead and create another piece of data. Let's create a simple sphere.
In fact let's create a number of spheres like this. Another very useful tip is that if you want to move the pivot point for an entity back to global zero, zero, zero before you do a reflect, for example. You can see all of these have their pivot points at the center of mass which is what you would expect for a sphere. Quick way to do it is to pick the entities, and it works on one entity or multiple entities and then just Control G to group. And you'll notice grouping by default centers the pivot back to the global origin.
So I could window over all of these, Control G and everything now is back to the origin there. And that's a really quick way to reset the pivot back to that location. Okay let's go ahead pick these entities, let's go to Duplicate Object, we're gonna reflect across the center line. And again now we've got these entities. So let's go ahead pick these entities and we're gonna go back to Non-proportional scaling and we'll scale vertically and again, the instances are not moving. So there's something strange about that particular command. Well there are certain commands in Alias that will not effect an instance.
Now to prove that these are true instances, let's go ahead, pick these entities, let's light up the control points and I'm gonna go into the front view and let's go ahead and pick CV's. And I'm gonna pick top of these CV's. Now you'll see those instances are lighting up. And if I say move now and move them up, you'll see they're behaving as they should do. Let's go ahead pick that data, pick this data here and let's delete that. So let's go back to the mesh. So what was the problem with the mesh? Again, a non-proportional scale does not work on an instance.
So let's see what we can do with the mesh. Let's just prove the point here, we're gonna select the mesh and just to check again, let's try a scale function. Scale function again doesn't effect the instance. If we go to Mesh, we're not gonna dive into meshes in this particular course but if we do a mesh subset for example, and let's just go ahead and pick this mesh. You'll notice now that the mesh on the other side lights up. So with subset we could actually create a subset of that mesh. But you'll notice the point here is that if I'm using a mesh function, the instance will behave as it should do.
But with a non-proportional scale or a scale function it won't. So just be aware of that when you're using copy or instance in this particular case.
- Manipulating views and entities
- Working with layers
- Creating curves
- Sweeping, extruding, revolving, offsetting, and blending surfaces
- Modifying geometry
- Moving, scaling, flipping, and rotating objects
- Trimming curves and surfaces
- Creating copies of objects
- Aligning, combining, and splitting objects
- Analyzing geometry
- Shading models