# Hopper Car Tutorial

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With the Train Engine completed, now Rich turns his attention to the Hopper Car. Much can be borrowed from what was learned in the engine, especially the wheels, but additional controls will be necessary to make the Hopper Car appear to have a suspension and have the Hopper Doors open and close easily. So Rich thinks through these issues with another Rig Sketch and then applies his ideas to the scene producing results that will fulfill the parameters necessary for the scene.

Users can jump ahead to a specific section by using the Chapter selection widget on the right side of the player or by directly clicking any of the Chapter Title links below.

Tab | Time | Chapter | Description
1 | 00:00:53 | Organize Layers | Organizing the layers to prepare for rigging.
2 | 00:18:03 | Rig Planning | Rig Sketch to plan out rigging for the hopper car.
3 | 00:26:38 | Rig Prototype | Prototype to test the ideas developed in the rig sketch section.
4 | 00:52:06 | Locators & Setup | Applying the prototype concepts to the actual Hopper Car scene.
5 | 01:04:25 | User Channels | Adding the necessary User Channels to the scene.
6 | 01:11:36 | Adding Modifiers | Adding the necessary Modifiers to the scene.
5 | 01:23:15 | Control Sway | Adding in the controllers to make the Hopper Car sway.
6 | 01:27:21 | Hopper Doors | Rigging up some controllers for the lower hopper doors.
7 | 01:38:27 | Parent Geometry | Connecting the geometry to the rigging locators.
8 | 01:41:51 | Spring Deformer | Adding in deformers and dynamic parenting them.
9 | 01:51:26 | Rig UI | Rig Sketch to plan out the Hopper Car rig controls.
10 | 01:56:14 | Add UI Controls | Adding in of the Rig UI controllers.
11 | 02:12:15 | Door Controls | Hooking up the UI controllers to the Hopper doors.
12 | 02:18:53 | Wheels Roll | Connecting the wheels and making them roll.
| 02:27:59 | Total Video Time |

Frequently Asked Questions--

Q.) He really can't draw curved arrows can he?

> A.) No, and its frustrating, you'd think it would be easier :)

Q.) Why are there times that popup menus fall off the screen?

> A.) The video was recorded from grabbing just a section of the screen. So modo knows there is more distance below where the menus are opened and will display it above or below depending on where the menu is opened from. This makes them appear to be cut off on the recordings.

Q.) He uses the words 'Heading', 'Pitch' and 'Bank'( and 'Sway' and 'Roll'), what do they mean?

> A.) These are just other terms for describing rotation in the X Y or Z axis'. Heading is rotation in the Y, Pitch is rotation in the X and Bank (or Sway or Roll) is rotation in the Z (if we are working in a Y up universe). There is nothing special about these terms so don't worry that you are missing anything.

Q.) He says "percentage" on the curve, I thought he said it was 0 to 1?

> A.) It is 0 to 1, internally, its just that sometimes it can be called (and by modo's default displayed as) a percentage. Don't worry about the term, if you see 100% it just means 1. The reason it is set to 0 and 1 and not percentages by default is that you actually pass a value of 0 to 1 out of any channel and it can be confusing if you start multiplying by 100% and wonder why you are only getting a factor of 1. For more info check out the Preferences section in the Foundation.

Q.) Did he really use the word "Funcicles"?

> A.) Yes, yes he did. Better than him saying the word Handy over and over again though, right?

Q.) He "zeroed" out the position of an item, what does that mean?

> A.) When you zero out something, say an items position, what is happening under the hood is modo will create a new position transformation item with the old position values and then clear out the values in the primary position channels. This way you see 0,0,0 but in reality there is position information applied in that other transformation item. Check out the Transform Items section in the Foundation for more info.

Q.) He goes to the channel list to drag channels into the schematic, why doesn't just just drag over the item from the item list?

> A.) That is because modo will not add any channel by default when you drag in the item. This may seem weird at first but if you look at all the channels that are on each item, if all those were to load at once the node would be a mile long in the schematic. By making you drag the channels you want in, modo forces you to have a more reasonable node size and channel count when you are working. For more info check out the Schematic section in the Foundation.

Q.) What is the "Work Plane"?

> A.) The Work Plane is modo's way of allowing you to model and place things in an arbitrary coordinate space. This is just a fancy way of saying you can tell modo what you would like the world X Y and Z to be relative too. We are not going to cover the Work Plane in any real death in the training, we more use it as a tool for alignment. For more info on the Work Plane check out the docs, for more info on how we use it for alignment, check out the Align Set Drop Tools section in the Foundation.

Q.) Wait, he just changed a modifiers type and didn't need to add it directly from the list, how did he do that?

> A.) A lot of the modifiers that you can add in modo are actually just a preset of the same modifier. For instance the Add, Subtract, Multiply and Divide Math Modifiers are really just the same modifier with a different setting. What he did here was change from a maximum to a minimum by changing that setting. For more info on check out the Modifiers section in the Foundation.

Q.) Did he just make a "War Games" quote?

> A.) Yes, Yes he did. And really, Marty's mom looked pretty good in that movie. Now get that one :)

Q.) He keeps calling himself lazy, after all the work I'm seeing here that can't be true is it?

> A.) Oh it depends on who you ask. I'm sure if you asked his wife she would agree with him wholeheartedly :)

Q.) He keeps saying "Wire" things together, what does that mean?

> A.) That term is just slag for connecting one channel to another, mainly because the connections in the schematic view look like curves or "Wires".

Resources--

Links to the modo in-line help system
Docs: Centers
Docs: Direction Constraint
Docs: Channels
Docs: Statistics and Info Panel
Docs: Schematic
Docs: Work Plane
Docs: Math Modifiers
Docs: WeightMap Deformer

Links to other pages in this training
Training: Pivots and Centers
Training: Constraints
Training: Channels
Training: Transform Items
Training: Curves
Training: Schematic
Training: Align Set Drop Tools
Training: Modifiers
Training: Deformers
Training: Assembly andRig UI
Training: Parenting and Hierarchies
Training: Groups
Training: Modifiers

File--

Links to the modo scenes used in the video
(click to open in modo)
File: HopperCar_00_Organize_01.lxo
File: HopperCar_00_Organize_02.lxo
File: HopperCar_02_RigProtype_01.lxo
File: HopperCar_02_RigProtype_02.lxo
File: HopperCar_03_Rig_01.lxo
File: HopperCar_03_Rig_02.lxo
File: HopperCar_05_Complete_01.lxo
File: HopperCar_05_Complete_02.lxo

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