Join Veejay Gahir for an in-depth discussion in this video Looking at layer basics, part of Alias Essential Training.
- It's very important in Alias, as we start to model, to be very organized in how we create our data and how we organize our data. Now, Alias uses a layer-based structure. If we look at the very top on a brand-new installation of Alias, we've opened up a brand-new file, and we have one layer assigned right now by default. Within Alias, you always have to have one layer, at least, active. In this case, the default layer is our active layer. We can tell that because it's yellow. If I click on this layer with my right button, you can see we can assign entities to that layer, we can pick objects.
We cannot make this layer invisible. That's been grayed out. We can create symmetry and we can set a state, as well. Right now, there are no other layers within this particular file. Let's create some. Very simply, we're going to go up to our Layers tab, and let's just say New. The default name for this layer is L1. You'll notice it's gone yellow, because that's the active layer. I can double-click on that. Let's just call this "Sphere." Return. Still the active layer because it's yellow. Let's go into Surfaces, right-click, Primitives, Sphere, and let's go ahead and create maybe just three spheres like that.
Then we're going to go to Pick and pick nothing. Again, we could start using our marking menus here, by picking object nothing, et cetera. Let's go into Layers, and let's create another new layer. Let's call this one "Torus." We're going to go to Surfaces, right-click, Primitives, Torus, and let's click ... Let's create three toruses there. Control shift marking menu, pick nothing. Let's do one more layer. In this layer, we're going to create a cylinder.
Let's go up to Layers, New, double-click, Cylinder. Let's go into our Surfaces, and under Cylinder, we'll create one, two, three. Again, marking menu, select nothing. Each one of those entities are going to be assigned to a particular layer. We want to assign the spheres to the Sphere layer, toruses to the Torus layer, and the cylinders to the Cylinder layer. Now, those layers were active when we created them, so if we right-click on the Cylinder now, which is the active layer, and make that invisible, those will disappear.
Torus, I can go right mouse button right over it, Invisible, and the toruses will disappear. The sphere also will disappear. You'll notice I've switched off all those layers. I've made them invisible. Again, Alias has to have at least one visible layer, and it defaults back to the default layer. To activate these layers, I just go to this right-hand square, just click it one time, click it one time, and that will bring those entities back into visibility. Now, those are not the active layers right now. To activate the layer, I have to click on the actual name and make the box yellow.
Like this, it doesn't really make a lot of sense. Everything right now is blue. Let's assign some colors. Let's just hold down the left mouse button on the square for the Sphere, and let's make that red. We'll hold down the square for the Torus and we'll make that green. For the Cylinder, let's make that purple. Now we can start to distinguish entities very easily in Alias, by just assigning colors. By the way, this is the color of the wireframe. It's not the color of the shaded model itself.
If I go up to Object Display, Diagnostic Shading, and let's use our Multicolor Shader. You'll notice that the color is all the same for these entities. It's just the wireframe that's changed. Let's go back to wireframe. I'm going to dock this at the top, and let's just hide that. Okay. Now what we can do is, I want to rotate the model around. I'm going to go ahead and Pick Object, using the control shift, select those spheres, and I'm going to right-click on the torus and assign them to the Torus layer.
Let's select nothing now. You'll notice now the torus and the spheres are green because that's where they're assigned, is onto that one particular layer. Now, I can do the same for the cylinders. Let's pick those cylinders, right mouse button, Assign. Then select nothing. Remember, to invoke the marking menu, control shift, left mouse button. Let's pick the cylinders and then we're going to assign them to the Torus layer, pick nothing. Now everything resides on the Torus layer. I have some layers here, the Cylinder layer and the Sphere layer, that are obsolete.
In fact, they don't have any entities on them. Sometimes during the modeling process, you have to do a little bit of housekeeping. When you have layers that have no entities on there, it can become quite confusing and the file can get quite large. So, very simply, what we're going to do is, go up to Layers, Delete, Unused Layers. Because the Sphere and the Cylinder have no data on it, those two layers were deleted. Now I can just right-click on this and make this invisible. Click on the layer to make it visible. If I make it invisible, I can't do that from here.
What I'm going to have to do here is click on this side here, and I still cannot make it invisible. When there's only the one layer active, like this, you have to select a different layer before this layer will become invisible. Again, it takes a little bit of getting used to, but this is not a real critical part of the process. You can't do anything wrong by trying to make things visible and invisible. Where things can go wrong is when you do a delete. For example, if I select this layer again, and I pick this object, and I say Delete, Yes to that, that data is gone.
It's gone for good. Let's Select Object again. I can say Delete on my keyboard. I can also press the space bar. So the space bar is another quick way of selecting yes. Now, those entities are gone for good. I can do an Edit, Undo, but there's no other way of retrieving except for an Undo, and the Undo has a certain amount of limits, too, as well. Just be aware, a Delete is an actual delete from your model. Let's do this. Let's pick these objects. We'll take all of these objects and we're going to just do Delete, space bar to accept, Layers, Delete, Unused Layers.
Okay. Let's open up our Diagnostic Shade again. We're going to go to Visual State One, or VS1. Let's just render that up. We'll close this again. What we're going to do here for this exercise is, we are going to assign each one of these letters to a specific layer. So Layers, New, let's create five new layers. We're going to rename this one Red, Pink, Blue, Green, and Gray.
Then also, what we're going to do is, we're going to change the color red, and finally gray, at the top here. Next thing to do is to use your marking menu, or you can use the palette, but just very simply Pick Object, select the object, and then just right mouse button over Red and Assign. And then right mouse button again, and make it invisible. We can also Pick Object from here. Select the object, Assign, and make it invisible. Now, you'll notice the object's still active.
The Pick Object command is still active, so we're just going to window over this, right mouse button, Assign, Invisible. Pick Object, Assign, Invisible. And finally, with the s, Assign, and Invisible. Now if I go to Layers, Delete, Unused Layers, those layers will still stay there. Even though they're not visible, they still have data on there. So they won't be deleted. Another point to note here is that I've made all of these layers invisible, so now the default becomes the active layer.
You have to have one layer active. Make these visible again, I can just select the layer. That's the active layer, and it's visible, or I can just make these invisible by clicking on the square that has the color assigned to it. To make this one active, just again simply select in there. Now, sometimes when you make a layer active, the other one will become hidden. You just have to click on the square to make it visible again. So that's the basics of working with layers.
- 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