Planetary Model Design

William Jones01/22/2015

Part A

Simplified High level design for a 3D engine

3D Engine with a GUIStart End

3D Engine specs

• Suggested engine Crystal Space http://www.crystalspace3d.org/

• Any 3D engine that creates a GUI should work• Must have spherical models• Must have animation paths• Must store static data that will be retrieved at

run time, and displayed in panel

10 3D Models

• Create 10 spherical models representative of the eight planets, (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) the Sun, and Earth’s moon

• Approximate color should match, but no texture required• Info at http://planetfacts.org/the-solar-system/• Scaled down is acceptable, all to the same scale• Will be view from a vantage on top of the z-axis where a

2.9 billion mile circular orbital path can be view just inside the view frame, ie. Neptune’s orbit is just within view at all times

Animation and Orbital paths

• The Sun model center will at the XYZ origin, (0,0,0)• Each of the 8 planets will have a circular line on the

XY plane a radius equal the max. distance from the Sun (scaled the same as the planets), and orbital path– The circular line will be white or transparent, adjustable

at run time– Orbital paths will linked to the related model

• An animation path for each planet will match the orbital path

The Earth’s Moon

• The Earth’s moon dose not require a circle showing its path

• The moon’s animation path will have to rotate around the Earth while the Earth moves on it’s animation path

Animation Speed

• One orbit of the Earth should take 10 seconds• All other planets animation speed should be

scaled to be proportion, thus Neptue’s 164.83 Earth year orbit should take 1648.3 seconds

• All animation speeds must be multiplied by a single animation factor variable

• The variable at this time will be equal to 1, but in the future could be use to adjust the global speed of the planets

The Camera view

• The camera will be above the XY plane along the Z axis, so that all of Neptune's 2.8 billion mile orbit is within the frame of view

• No lighting effect at the current time, although a light in the Sun may be desirable later

• The camera will be fixed and not move at this time, nor will zooming be allowed, however in the future these features will be desired

• The background will be solid black

Planet Data

• Each of the 10 models will have static data associated with it

• At the current time this data can be hard coded with any number of facts from http://planetfacts.org/the-solar-system/

• In the future, the data will be loaded in from a database at application startup

The GUI

• The GUI will have three buttons, two toggles and one “Exit” button

• One toggle button will be play and pause the animation

• The other toggle will display and hide the orbital paths

• The “Exit” button ends the applicationOrbits

Exit

GUI

• The orbital paths and the 10 Models will be selectable (clickable)

• Upon selection, half the GUI will be filled with a panel displaying the data related to that model

• Any selection (click) will remove panel, when the panel is displayed

Orbits

Exit

Neptune is the forth largest planet.

Neptune in Roman mythology is the god of the Sea

What to do next

• Get a game design or 3D engine expert to review this design and offer feedback

• Get a 3D engine code to explain back to me what I have in this design

• Look for feedback from the client, that the GUI is shaping up like they want, and the most important features are included

Part B

Simplified High level design for a 3D engine

Abstraction

• 3D model are abstraction, and I defined then only to be respective of the planet

• The GUI defined in general term and with elements likely to be in any GUI

• Circles to represent orbital paths are an abstractions manifested in the design

• The camera view is used to show where the view point of the users is

Detail added

• Any details where two or more items where connected added – orbital path match animation paths and are selectable

• Static data would be connected to the models and displayable

• Ruff images of how the display should look• Images of the buttons desired

“Good Enough”

• When I ran out of things to describe• I would go over the slides and try to see if I

had enough detail, where I would know what to do, if I were coding this

• Dead line coming up. It is 5:40am on the 22ed, my original idea died, and this is the much simplified replacement

Requirements or Design

• This is more requirements to me• It is you must have this and that• There is some design in that proper

requirement do not say use this type of button or anything that forces the coders down a certain path

Rejected design

Research showed the physics of depicting orbits as they truly are, is

not feasible at the current time

Concept

• Many stellar bodies of interest orbit or are satellites of other parent bodies, who intern have parents, etc.

• Those the do not have parents move in a liner path, thus all motion could be defined relative to each other and apply not just to our solar system, but many

Object Interactions

Start

Stellar Objects Stellar Objects

Database

GUI

User Input

Graphic Output

End

Initiation

3D Engine

Stellar Objects are use polar coordinates based off a parent Stellar Object. The ultimate parent is the universe center.

Research on polar coordinates and Stellar Date/Time required.

Parent stellar objects have a normal orbital plane. Parents have satellite children, who become part of their FarMass.

All stellar objects have vector of motion. If the object has a parent other then the universe center, then an orbit is created. The orbit may not match the normal orbital plane of the parent. Additional gravitational forces can alter the objects orbit.

Rotational Axis are independent of other factors.

StellarObject

ParentStellarObject: StellarObjectSatellites: LinkedList <StellarObject>MotionVector: Polar3DVectorParentMass: LongNearMass: LongFarMass: LongOrbitAngle: Polar3DOrbitAngelAxis: PolarLineNomalOrbit: PolarPlaneStartLocation: PolarLocationStartDate: StellarDateTimeFacts: FactMapGavitationalPulls: LinkedList <StellarObject>Location(StellarDateTime);GetSatlites();LocationFromUniverseCenter(StellarDateTime);GetFacts();GetParent();GetAxis();

Stellar Object Class

Research on polar coordinates and Stellar Date/Time required to define Polar3D Vector, Polar3DOrbitAngel, PolarLine, PolarLocation, and StellarDateTime.

Model3D is a 3 dimensional model that the GUI will show multiple views of. A 3D Model class should exist in the library.

The database can be expanded to include other types of standard data, as the client requests.

StellarObject

+SellarID: IntName: StringModel: Model3DOrbits: SellarIDSatellites: Table <ParentStellarID, SatelliteStellarID>MotionVector: Polar3DVectorNearMass: LongFarMass: LongOrbitAngle: Polar3DOrbitAngelAxis: PolarLineNomalOrbit: PolarPlaneStartLocation: PolarLocationStartDate: StellarDateTimeGavitationalPulls: Table <StellarID, GavPullsStellarObjectID>Population: StringAtmosphere: StringTemperature: LongOther: Memo (additional info as client asks)

Stellar Object Database

3D Engine

• Identify a 3D engine that works with the desired programing language.

• The 3D engine must bind to an adjustable view in the GUI

• Objects in the 3D view must be selectable• 3D objects must be linked to stellar object

instances• Stellar object instances will define object

movement, and can return facts about the object

GUI Initiation

1. Default parent = Sol (our solar system) of the Milky Way galaxy

2. Query database for parent object and create StellarObject populated with database information

3. Create 3D object of parent and place it in the center of the 3D view

4. Repeat step 2 for each satellite of the parent5. Place satellite relative to parent in the 3D view

based on the current date

GUI User Input

• Date/time to be viewed: calendar and time spinner

• Speed to step forward in time: integer spinner• Parent to center on: selectable list• Clickable objects in 3D view• 3D rotation controls: X, Y, and Z (integer

spinner and graphic hand control)• Play/pause: toggle button

Realization of using 3D

• At this point, I realized, I wanted a 3D engine to create the view inside the GUI

• While I was looking for a 3D engine likely to allow being inside a standard application, I also started looking at what the 3D physics engine could do

• This lead to looking deeper at physics evolved for a real simulation and the fact an accurate simulation can not be done

• Then it dawn on me 3D engines do their our GUI flipping the project inside out

Information Links

• http://star-www.st-and.ac.uk/~fv/webnotes/chapter6.htm

• https://en.wikipedia.org/wiki/Cosmic_Calendar• https://en.wikipedia.org/wiki/Julian_day• http://

answers.unity3d.com/questions/27792/orbit-sim-without-physics-engine.html

• http://www.crystalspace3d.org/main/Features• http://

www.arachnoid.com/orbital_dynamics/index.html• http://planetfacts.org/the-solar-system/