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4. Layers |
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 It's hard to keep one part of an object separated from another. Once you create a part, it's polygons will obscure the one behind it. Thus, you need ways to keep pieces of your object separate as you work on them. If you take a car, for example. You create wheels, the body, the engine, the seats, etc. If you were to draw the body, it would be very difficult to draw the seats because the body would surround the seats... Yet, on a car the body is the deciding factor as far as fitting everything else inside, so it only makes sense to create the body first. This is the purpose for 'Layers'. Just as with Photoshop or other programs which allow layers, they let you view just a piece of the object at a time. MODELER, WHERE ARE LAYERS? Layers reside at the upper-right corner of your screen.   MODELER, LAYER 1 IS THE DEFAULT When you first start the Modeler program, the default Layer is Layer 1. Only if you purposefully change the layer to a different layer will the layer change. To change to another layer, point your mouse to the second box from the left that is divided by a diagonal line. You must click the top-left of the diagonal line that divides the top-left half of the layer button from the bottom-right half. The 2nd Layer indicator will turn entirely yellow and the ball will disappear from all four views.   MODELER, THE SMALL TRIANGLE'S MEANING Notice that there's a small triangle in the upper-left corner of the Layer 1 indicator. This shows you that that layer has content in it.  MODELER, BOTTOM-RIGHT HALF BELOW DIAGONAL OF LAYER CONTROL Now, in order to place the box you're about to put down you will have to see the object in Layer 1, but you wish to BE in Layer 2. Therefore, hold the SHIFT key down (meaning you want BOTH layers to be seen together) clicking on the bottom-right half below the diagonal line of Layer 1. Only the bottom-right half of the Layer 1 indicator will highlight.  MODELER, BACK LAYER The ball will appear, but the polygons will be black, not white. When the bottom-right part of a Layer Indicator is selected, and the polygons in 'Wireframe' view type are illustrated with black lines, this is termed a 'Back Layer'. When an entire Layer Indicator is selected, and the polygons in 'Wireframe' view type are illustrated with white lines, this is termed a 'Front Layer'. You can SHIFT-click the bottom-right half of another layer to add that layer to the 'Back Layer', or SHIFT-click the top-left half of any layer to add it to the 'Front Layer. You can only see the relative relationship between polygons in the Front and Back Layers when you are in 'Wireframe' view type. No tools can affect the black points or polygons of the 'Back Layer', you use these black indications to help you place white (Front Layer) points or polygons.  Now, select the 'Create' tab and pick the 'Box' Tool. Drag to expand the size of the box in the upper-left 'Top' viewport to make it look like it is sitting on top of the ball. In the 'Back' viewport, drag the height for the box, positioning by dragging the center cyan cross until it sits on top of the ball.  So, to recap... polygons that are in the 'Front Layer' of any viewport which are set to the 'Wireframe' view type display as white. All 'Back Layer' polygons and points that are in viewports set to 'Wireframe' view type are represented as black. MODELER, CONTENTS OF TWO LAYERS MOVE AT ONCE Hold the ALT key down, click in the 'Perspective' viewport. Move the mouse to visually rotate the objects and you will see that both Front and Back Layers will visually rotate together. (Remember that the ALT key trick only VISUALLY rotates the world. It doesn't rotate the objects RELATIVE TO that world). Unselected layers aren't visible, of course. Choose the 'Select Polygons' button  (or press CTRL-g), making sure that the cursor is the 'Polygons Without Any Chosen Tool' cursor.   MODELER, DEFINING SURFACE NAMES Press the 'q' key to bring up the 'Change Surface' panel. Type 'Box' into the 'Name:' gadget, pick a color for your box, and click OK. It's good to give a 'Surface Name' to a layer's polygons. That way, if you forget and accidently paste two layers together, it'll be easier to isolate those polygons again, set their color attributes, or add texture maps to those surfaces. IMPORTANT - Any time that you give a name to polygons by pressing 'q' to envoke the 'Change Surface' requester, that's called a 'Surface Name'. MODELER, "THEY TORE MY ARM OFF AND THREW IT OVER THERE" or "...THAT'S YOU ALL OVER". Now, we're going to split the sphere in half, putting the bottom half into Layer 3 and leaving the top half in Layer 1. Click the top-left diagonal of 'Layer 1', making it part of the 'Front Layer'. All previously defined front and back layers will no longer be visible. The box will disappear, leaving only the ball behind. IMPORTANT - When you click, without holding the SHIFT key down, whatever layers that were front or back layers will become de-selected from both their Front and Back Layer definitions. I'll be working in the lower-left 'Back View' pane. To give more area to work in, I'll expand the size of that viewport. To change the relative sizes of viewports, position the mouse at the center of the four view panes. The cursor will turn into four directional arrows.  Make sure that all tools are unchosen, that you have the 'Select Polygons' button pressed (Press CTRL-g to make sure). Ensure that the diagonal cursor which indicates 'Polygons Mode With No Chosen Tool' is the current cursor.  MODELER, MOVING THINGS FROM ONE LAYER TO ANOTHER Press the 'x' key to cut the bottom half of the sphere to the clipboard. Notice that it is just the x key and not CTRL-X as you'd expect. This is because the program originally came from the Amiga platform, not the IBM platform. The bottom half of the sphere has disappeared. Click the top-left part of the 'Layer 3' button to select that layer as the current front layer. Press the 'v' key to paste the bottom half of the sphere into Layer 3. It should appear. MODELER, NOT USING CTRL KEY WITH COPY, CUT AND PASTE It's hard to get used to NOT pressing the CTRL key when you do a Cut, Copy or Paste command. However, at least the three keyboard shortcuts are the same letters in all three cases. 'x' for Cut, 'c' for Copy, 'v' for Paste. If you DO forget, and press CTRL along with the letter, you will get: CTRL-v - Sets an X, Y or Z valuePress the bottom-right of the Layer 1 button to show it as the Back Layer and you will see the whole sphere again, only the bottom will be white and the top will be black.  MODELER, MULTIPLE LAYERS PER DOCUMENT If you use up the ten layers, you can select more layers for a document. To the left of the ten Layers gadgets are an 'Advance a Set of Layers' button (right-arrow) and 'Back up a Set of Layers' (left-arrow) buttons.  LightWave will remember, however, which layers were selected, and unless you change which layer is selected, it will reappear once you go back to that set of layers. MODELER, MULTIPLE DOCUMENT LAYERS Whenever you load another .LWO Object that had been previously saved, it will appear in the drop-down menu to the left of the 'Advance and Back-Up a Set of Layers' buttons (that I just mentioned). The current object name will appear in that drop-down menu area.  To choose another document, click the down-arrow to the right of the name  and a drop-down menu will appear.Remember that in that document, also, if you use up more than the ten layers, you can choose an unlimited number of sets of ten layers by clicking the right arrow to go up a set of layers and the left arrow to go back a set of layers.  If you wish to load an object file, and have the old object file go away, you must manually close that object. To close the currently selected object you choose 'File->Close Object'.  If you have moved the set of layers above the number one set, bring it back to Set 1 by clicking the left arrow. One warning... If you ever accidently have the CAPS LOCK key pressed, and you are pressing the 'n' key thinking you will bring up the numeric requester. SHIFT-n does a 'New Object'. It will look like you suddenly deleted the object you were working on. It isn't gone, it's just been replaced by a blank object called 'Unnamed'. If you go to the drop-down menu and choose your old object name, it'll reappear. If this happens, merely select the 'Unnamed' object from the drop-down menu and do a 'Close Object' to remove it. MODELER, MERGING TWO LAYERS Next, is how to merge two layers back together so they're the same as they were before you cut them apart. Make sure you are still on Set 1 of the proper document (probably called 'Untitled' if you haven't yet saved it). Click the 'Layer 3' button  and you'll again see the bottom half of the sphere. Make sure no other layers are selected as either background or foreground layers.Make sure that the Polygons button is pressed and that no tool is chosen. IMPORTANT - You can have multiple foreground layers by shift-clicking the TOPS of layer buttons. They will both highlight and you will be able to do actions on all selected layers at once. When no polygons are selected, using a tool will work upon every polygon in that layer. That's important. So, that means that you can 'Cut' all polygons in Layer 3 to the clipboard by just pressing the 'x' key without actually highlighting any polygons as long as I can ensure that no polygons are selected (Sel: 0). Press 'x' and the bottom half of the sphere will disappear. Click the top-left part of the 'Layer 1' button and press the 'v' key to paste the bottom half into 'Layer 1' again. Even though it looks the same as it once did, that doesn't mean it's exactly the same. Remember when you highlit the bottom polygons and did a Cut to the clipboard? Well, when you did that, it made two sets of points that resided in the exact same space in your 3D spacetime. Now that you've pasted the bottom half back in place, there are two sets of points around the perimeter of the sphere that are now doubled points. You can prove that the two halves are not connected together with a handy feature. Make sure all Polygons are unselected (Sel: 0), highlighting one polygon of the upper-half of the sphere. At any time you can tell LightWave to select every polygon that is in any way connected to a selected, or multiply selected polygons by going to some polygon in the upper hemisphere of the sphere, pressing the left mouse button and holding it, then drag the mouse across one of the polygon sides. Two polygons will highlight in the upper hemisphere.   Now, you have to highlight just one of the Points along the hemisphere's 'equator'. There are a couple ways to do that. I will use the Wireframe ViewType as an example of how to do it. Go to the bottom-left 'Back View' and make sure it is in 'WireFrame View'. Highlight any point along the centerline of the sphere.  MODELER, SHARING SPACE That is proof of what I was telling you before. When you copied the upper half of the sphere, it duplicated the row of points or you wouldn't have been able to see that last set of polygons just before the horizonline back when it was split in half. The same was true of the top half, that it had also duplicated that line of points in that layer when it chopped the bottom half away from it. Thus, when I pasted it together, there are now two points that are exactly on top of each other in all three X, Y and Z directions. There are also the two sets of two points on alternate sides of the sphere. So, in all, there are four points highlit. Click with your mouse and hold the left mouse button down on one of the two sets of highlit points in the bottom-right 'Right View'. Rub back and forth like you're erasing the point until the selection goes away and only one set of two points is highlit.  MODELER, WELDING TWO POINTS INTO ONE Now, you're going to weld two points together. Welding can be very handy when you're constructing polygon meshes. Always remember that all points should be joined together. This is very important when you are working with Subsurfaces as strange things occur if two points happen not to be welded together and you try to do a TAB on them. Verify that it says Sel: 2, and press CTRL-W which will weld the two points together.  Realize that every other set of two points around the perimeter is also not welded together and we'd have to highlight each pair one-by-one and weld them without missing any if we wanted to weld the two halves manually. MODELER, USING 'MERGE POINTS' To have it weld all those exact same points together, all at once, you can learn a trick. Again make sure that all polygons are unselected, that the Polygon button is on, and that the proper cursor with diagonals is there. Go to the Construct tab, and select the 'Merge Points' button or press the 'm' key.  MODELER, ONE POINT POLYGONS Here it may be noted that there's a checkmark which says 'Keep 1 Point Polygons'. Yes, you can have both 1 point (good for stars and such) and 2 point polygons, but oftentimes they end up there as mistakes. Sometimes a polygon got duplicated, then points were welded together, but not all the polygon's four points. In that case, you end up with straggler points. If you know that you have no legal 1 point polygons, delete them. Keep it at the default, 'Automatic' setting and click OK.  MODELER, MULTIPLE LAYERS LOAD AND SAVE AS ONE OBJECT And, that's how you do Layers. When you go over to Layout program, you'll notice that each separate layer will be loaded into the Layout as a separate object. There, you will have to keep all these associated parts together by creating a Null Object, and parenting all the pieces to that null object. Then, to move the objects as one part, you move the Null Object. More info later when we talk about the Layout program. And, so ends the lesson on Layers. Next, comes the ability to Mirror points. |
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