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14.3 The Layout Program, Bones - Part 3
 
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LAYOUT, WHAT DOES RENDERING MEAN?

Rendering means, 'Draw the 3D Image From the Camera's Point of View'.

The Layout program bounces light rays off objects, computing what the light will then look like as it hits the camera lens.

It computes reflections, refractions, surface textures, etc. as it follows each light ray.

The intricate process of following the path of individual light rays is called 'Ray Tracing'. It's very similar to what happens in the real world when your eye looks at an objects that are being illuminated by light rays from the sun.

Luckily, you need to know little about what the program is actually doing.


LAYOUT, RENDERING OPTIONS

You DO have to worry about the rendering options that may need to be set, though.

At the top-left of the Layout window, from the drop-down menu, Select...



Set the following settings.



You don't currently need 'Ray Trace Reflection' as there are no reflections in this object, but you may need it in the future and it might confuse you to turn it off.


LAYOUT, RENDERING A SCENE

When you press the 'F9' key, you should get a window which looks like this:



It may work a few seconds, then it should give you a second bigger window containing the finished rendered image.

This is what 'Render Display: Image Viewer' does. If you chose '(none)' for the Render Display, this window won't show. You turn this window off when you create long animations to render faster.



The light is what creates the shadows in the image. If you moved the light more to the left, there would be more shadow on the right side of the body.

Close both rendering windows and select 'Top' view from the drop-down menu at the top left of the window. Click on the purple 'Distant Light' to select it. It should turn light-yellow.

Make sure that the button is selected in the 'Tools' section of the 'Items' tab or press the 't' key.

You might find that the front-end of the light is within the surface of the object.



The red arrow lets you move the light down and up in the viewport and the red arrow lets you move the light left and right.

Click the blue arrow with your left mouse button, hold it down, and drag the mouse upwards relative to your monitor. The light should follow your mouse movement.

Click on the red arrow and drag it to the left.



Next, pick the button from the 'Tools' section of the 'Items' tab or press the 'y' key.

The 'gizmo' changes from the arrow gizmos to the rotation gizmos. Gizmos are the red/blue/green 'adjust' tools which appear when you enter a certain mode.




When you select a 'Distant Light' in the 'Layout' program, while 'Rotate' is chosen, three-colored 'gizmos' appear.

When the 'Rotate' mode has been engaged, you can see the rotate gizmo. The three colored circles allow you to change either the Heading, Pitch or Bank of the light. If you click the left mouse button on the red circle, then move the mouse left and right, the light will rotate its heading left and right.




LAYOUT, GLOBAL VS LOCAL COORDINATE SYSTEMS

The LightWave manual shows what the definition is as far as what is termed the 'Global' coordinate system. If you were to look at the three X, Y, and Z axes, in the glogal coordinate system, Heading, Pitch and Bank mean the following:



However, when dealing with the rotation of bones, or an object, this global definition won't help you much.

Stick with me through this part. When dealing with 3D sculpture, mental gymnastics are common. You'll definitely need to learn how to use your imagination to rotate things in your mind.

You'll need to have the ability to change your relative point of reference, if necessary.

Just follow this a step at a time, and if you get lost with what I'm saying, re-read that section.

Let me illustrate. I'll use LightWave's global defininition of what rotations mean.

If an airplane's nose were pointing towards you with it's wings stuck out to the sides the nose would be aligned with the Z axis. You can't see the Z axis here because it would go in and out of the TV screen. If the body were aligned with the Z azis, the wings would be aligned with the left/right X Axis.




If the airplane were to bank, then it would have to rotate around the Z axis.




If it were to change its pitch it would rotate around the X axis (viewed from a 45 degree angle relative to the X axis).




And, finally, if it were to change its heading it would have to rotate around the 'Y' axis.




This would conform to what LightWave's global diagram shows.



What I just said equates with this diagram.

In the same way, if a person's nose were pointing forward (aligned with the in/out Z axis) and their ears were lined up with the left/right X axis, then again the definitions they gave would be true. When they changed their head's heading by shaking their head 'NO', it would rotate around the 'Y' axis.



However, that gives the illusion that the three terms are always fixed at some global position in space, which they aren't.

For example, if I again talk of an airplane, if an airplane took off from Boston and it headed due south towards Florida, the pilot could arbitrarily pick the fact that North/South was along the Z axis in his 3D world. (In that case, in our 3D world, the plane would be flying straight towards us)



But, if the pilot then decided he wanted to, instead, fly to San Francisco, he could change his heading by rotating around the Y axis (in the real world, the plane would also have to bank by lifting the left wing and dropping the right wing, but in this ideal world lets say the plane can just change its heading without banking) and now he would be heading in the same direction as the X axis heads (the airplane would then be heading towards our left).



This is a major change in heading. It's a 90 degree change of heading.

But, if that pilot then decided to land his plane, there's no reason he would have to first align himself North/South before he could land. At any moment he would merely dip the nose of his airplane to land, and so in this case that would make the Z axis the pivot axis for his pitch angle instead of the X axis as it would have been originally, before he changed his heading.



From this you can see that heading, pitch, and bank are all relative to the relative direction of the object. Which way you choose to call 'forward' and 'backward' for an object is what determines the three definitions. When you deal with Heading, Pitch and Bank in such a relative manner, it is called using a 'Local' coordinate system.

Now, that wasn't so bad, was it?


LAYOUT, COORDINATE SYSTEMS

From the manual:

In the Layout Program, the Coordinate System setting (Items > Motions: Coord System) affects the Move, Rotate, and Move Pivot Pt tools.

World allows easy movement based on the world axes, even for items deep within a hierarchy that contains rotated parents.

Parent is for movement based on the axes of an item's parent(s). If an item has no parent then this setting is equivalent to World.

Local is for movement based on an item's own axes. In the Layout program, Local Coordinate System can be temporarily activated by holding the CTRL key down.

NOTE:

One thing to remember about Local and World rotation is that they are only for interactive manipulation.

Internally, the Parent system is always used since it's the only one that can encode absolute rotation values.

This will affect how an item's orientation is interpolated between two keyframes. As such, rotating the pivot point might still be useful in some situations.
Rotating an Item:

When you adjust rotation, in contrast to adjusting position, the action is relative to the global axes around the item's pivot point (discussed later).

By default, the pivot point is at the item's local Origin.


LAYOUT, ROTATING A LIGHT

So, looking down on the top of the light, Heading would be the red circle.

Click anywhere on the red line with your left mouse button and keep the button down... now drag the mouse to the left or the right. The light rotates in a circle and the lighting changes upon the surface of the arm to now be backlit instead of being lit from the 'front' (light pointing towards the front of our 3D world in this case, light falling on the 'back of the object' which is really the front bacause we have the object turned backwards - simple isn't it?). Rotate the light until it points at the arm.



Now, a mistake that many beginners do is they now hit the 'Render' button to see the changes. Only makes sense... And, it might have even worked if the were selected.

However, if Auto Key is NOT selected (which is the way I like to work, if it is currently selected, unselect it). If Auto Key was not selected and you hit render now, you would get the exact same render as you had before, with the light at the front of the arm AND THE LIGHT WILL HAVE MOVED BACK TO THE POSITION IT WAS IN BEFORE YOU MOVED IT.

To get it to save the changes you made, if 'Auto Key' is turned off, you must click the button (or press ENTER key) to get it to remember the changes you made to that light.

You can think of 'Create Key' as meaning, 'Remember the Changes'. So, any time that you moved any object, light, or camera, you must tell it to remember the changes you did by clicking on 'Create Key' or pressing the 'RETURN' or 'ENTER' key on your keyboard.

A 'Create Motion Key' panel will appear.



'Create Key At' is asking for a frame number. If you are just creating an image, you stay on Frame zero. If you are doing an animation, you will be creating other frames. This is the 'Frame Gadget' which allows you to select a frame other than frame number zero. To the left of the 'Frame Gadget', that is the current frame you are on.



Since you haven't moved the Frame adjustment gadget, and since you are just rendering one image, it should be set at zero which is the first frame.

Most of the time you just will be clicking 'OK' when you do a 'Create Key'. Click the 'OK' button.

Now you are ready to press the F9 key to do a new rendering. Now, the arm is backlit. If the lighting isn't quite right, select 'Move' by pressing 't', move it, select 'Rotate' by pressing 'y', rotate it. Click on 'Create Key', click on 'OK', then press the 'F9' key.



This sequence of picking 'Move', moving something. Picking 'Rotate', rotating it, then doing a 'Create Key' is a set of movements you will do thousands of times in an animation because every bone movement, every rotation of the head, every movement of any sort takes these three actions.


CREATING ANOTHER LIGHT

When you create a light, you will have to change the default of 1 OpenGL lights (if your graphics card supports OpenGL rendering, that is). An OpenGL Light means that the program lets you preview what that many lights look like all at once. If you have it set to 1, any light that you create won't be added to your preview, so will be way too bright when you do a render. This can be very confusing for the beginner. Why LightWave chose 1 to be the default, I don't know.

To increase the number of OpenGL lights, Select 'Display Options...' from the 'Layout->Options' menu or press the 'd' key. Change 'Max OpenGL Lights' to 4. Luckily, after the first time you change it, LightWave will then automatically remember that you want four lights. If you ever use more than four lights, though, try and remember that you'll need to raise this value.



Generally, objects are lit with three lights. One 'Distant Light' (the default light) that's set between 90 - 100%, one 'Area Light' to the right that is about a 40 - 50% light level, and a back 'Spot Light' that's set to 30%.

At the moment, there's a Distant Light' as a backlight and no front light so lets create a front area light. Area Lights are not as harsh as spot or distant lights, so are good for illuminating skin.

Zoom out a bit in the 'Top' view by pressing the ',' key (just as in Modeler). From the 'Add' drop-down menu pick 'Lights->Add Area Light' and call it 'FrontLight'.



Click 'OK'.

Layout always places any newly created thing in the center of the world at the 0,0,0 position. If your object is also at the 0,0,0 position, then sometimes it is hard to see. Press 't' or from the 'Items' tab, 'Tools' section pick 'Move'.



Pull the blue arrow downwards and the red arrow to the right.



Then press the 'y' key to rotate the light and rotate the heading so that the light points at the arm.



To have Layout remember the position changes make sure you press the button to create a 'Motion Key' for the new light and press 'OK'. Press the 'F9' key to render the arm again.



Depending upon the type of mood you wish to create, you could create another 'Distant Light' and place it to the front-left of the arm. Generally the backlight is a spotlight rather than a 'Distant Light'.


To keep from repeating myself I won't explain how to animate here. For more on using the Layout program for animating please see Chapter 41.

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