CauseF manual (version 4.5)

Contents

Overview
Grid - Key points, Settings window, Grid window
Spheres - Key points, Settings window, Spheres window
Planets
Contact and bug report
Copyright and credits, history

 

Planets

Key points
Settings window
Planets window
Planets defaults window

Note: Anti-aliasing may not work unless it has been enabled in the monitor settings.

Key points

You can
- set the initial number of planets;
- set the number of fragments after a collision between planets;
- divide the planets into groups, each with their number of planets and their colour;
- set the initial positions of the planets, randomly or in groups (and position the groups in 3D space);
- set the force fields of the sun and that of the planets;
- adjust the speed of the planets, either initially or constantly;
- allow the sun to move under the influence of the combined force fields;
- launch planets or remove planets during the operation;
- change planets into stars and back again;
- fast-save scenarios to capture the exact position of each planet and the sun, to be restored later;
- slow down the frame rate for the display;
- view the scene from a distance, from the sun, or from one of the planets (looking forwards or towards the sun);
- change the viewing angle, zoom distance;
- view the paths of the planets to see their orbital patterns;
- play sounds (collision with another planet, collision with another planet and fragmentation, plunging into the sun).

Observe the orbits of the planets as they are influenced by the force field of the sun as well as by their own force fields, all of which are a function of mass and distance at any given moment.

And further:

The orbits of planets are a classic example of nonlinear systems due to the interdependent nature of such systems. Planets act under the gravitational field of their star, but they also possess their own gravitational fields. These forces cause the planets to accelerate towards their star, they decelerate when moving away from it, and all the while their own gravitational fields exert an influence as they get closer or further away from each other.

In space the scales are huge, in terms of the celestial bodies themselves as well as the time lines. Thousands, millions of years are shrunk to minutes in CauseF. The principles underlying the forces however are the same.

As planets are launched one by one, or started as groups placed somewhere in space, they settle into orbits under the influence of the varying force vectors.

The gravitational pull from the sun drives a planet towards its perigee (the point closest to the sun), accelerating as it does so. Once past the perigee it shoots outwards until it reaches its apogee (the point furthest away from the sun), decelerating as it does so.

There are two potential problems: (1) the trajectory of the planet causes it to plunge into the sun, and (2), its velocity is so high it surpasses the point at which it could be pulled back to the centre, in which case it continues to move on until it leaves the influence of the sun entirely. Both cases ultimately depend on the planet's velocity; too slow on approach and it gets pulled in, or too fast and it continues outwards.

The velocity in turn derives from the planet's and sun's mass (ie, their combined gravitational pull), and any other force field the planet may encounter as it gets closer to other planets.

The development of orbits can also be observed when two planets hit each other. In the case of no fragmentation (set by the user), the larger absorbs the smaller and its changed mass influences its orbit from now on. Or, with fragmentation set, upon collision both planets change into fragments (how many is set by the user) and the resultant clusters will enter some orbit, or some parts may be driven away because their impact velocity overcomes the sun's gravity. All of which is influenced by any other planets in the proximity.

The more often a planet has collided with another and has not been absorbed, the larger it gets and its increased mass and hence velocity may drive it closer to the sun. Provided it doesn't hit the sun the result is a large planet in a high-speed and tight orbit which may be quite stable (according to the program's time scale), but sooner or later it will collide with the sun. If a planet hits the sun the planet disappears and the sun absorbs its mass; its own gravitational field has become stronger.

A similar scenario can occur if a planet is turned into a star. The planet will adopt the sun's current mass (and hence gravity) and the result is a virtual binary star system (more than one planet can be turned into a star of course).

One way to demonstrate how difficult it is to anticipate the planets' movements is to attempt to launch a planet with the aim of hitting another (the launcher can be rotated left/right/up/down). Perhaps sharp shooters may have an advantage here, but using a high-velocity round to hit a more or less stationary target is quite different; the nonlinear factors would have highly compressed probabilities. In our case the probability ranges are quite large.

Instead of viewing the planets as spheres they can be rendered as unerased points and therefore reveal their paths. The orbits' stability or otherwise can be seen clearly, and their outlines can turn into wing-like forms because there are actually two orbits entered one after the other.

The more elliptical the orbits are, the greater the chance the above-mentioned scenarios will take place. Almost circle-like orbits are nowhere near as dramatic. Hence residents of planet Earth can relax (it may well be the reason why Earth is still around after billions of years).

Settings window

In order of appearance, left to right, top to bottom, by section:

(1) Start with movements
The movement of planets can be fast-saved (Ctrl+S) with the positions and all the other parameters stored in a file. If such a file is loaded, checking the box will start the planets with all the positions etc in place (using the F1 hotkey). If unchecked, the planets revert to their starting position (similar to clicking the (13) - Planets - Apply button and opening the Planets window).

(2) Play sound
If checked, 3 types of sound are played: when a planet plunges into the sun, when a planet hits another, when planets turn into fragments. The sounds are modified according to mass and distance.

(3) Planets - Initial number of planets
Sets the number of planets available when opening the Planets window. It acts as a reference only; during operation more planets can be added by using the P hotkey to launch, and planets can also be removed.

(4) Planets - Fragments after collision
0 - no fragmentation. A number > 0 sets how many fragments the planets turn into once they have collided with each other.

(5) Planets - Custom setup
If unchecked the Planets window opens with the first planet ready to be launched. If checked, one or more groups (maximum 5) can be set and they will be positioned according to (10) Planets - Special positioning. The groups with their planets will appear as the Planet window opens.

(6) Planets - Number of groups
Sets the number of groups (maximum 5). Note that the initial number of planets will be divided among the groups by default at first (no remainder used at this stage), and the actual number of planets per group can be defined later on.

(7) Planets - Group
The ID of a group (ie, group #1, group #2, ...).

(8) Planets - Planets
The number of planets for this group. Altogether the numbers must not be larger than (3) Planets - Initial number of planets.

(9) Planets - Colour
Defines the colour of this group.

(10) Planets - Special positioning
The planets in the groups can be positioned at startup.

(11) Planets - Random
All the planets in the groups are randomly distributed throughout the space, regardless of their group membership. Note: if not all of them are visible, zoom out (see Hotkeys).

(12) Planets - Cluster
Planets are clustered in terms of their group membership. Each cluster can be moved around (see Hotkeys) with the relevant (7) Planets - Group ID selected.

(13) Planets - Apply
When clicked all the settings in the Planets and Dynamics panels are sent to the Planets window (with (1) Start with movements checked the button is disabled). During operation only the settings in the Dynamics panel can be modified.

(14) Dynamics - Activate sun
When checked the sun moves under the influence of the combined gravitational force field of the planets. If then unchecked, the sun will stop moving.

(15) Dynamics - Reset sun
Resets the sun to its original position at startup. Clicking this button does not influence the (14) Dynamics - Activate sun checkbox.

(16) Dynamics - View from afar
Default. The scene is viewed at an angle and zoom distance set with the relevant hotkeys (see Hotkeys).

(17) Dynamics - View from the sun
The view is from the sun. It can be rotated left/right/up/down with the relevant hotkeys, but zooming is disabled.

(18) Dynamics - View from a planet
A planet is selected by the program to act as a base; if groups are used a planet is taken from (20) Dynamics - Group. Should that planet disappear (collision, into the sun, flung into space), launching another planet will provide a new base. The view can be rotated left/right/up/down with the relevant hotkeys, but zooming is disabled.

(19) Dynamics - Look forward
With (18) Dynamics - View from a planet selected the view is in the direction of movement.

(20) Dynamics - Group
The group ID from which the planet to act as a viewing base is drawn. Works only if (18) Dynamics - View from a planet has been selected.

(21) Dynamics - Look towards sun
The view is from a planet towards the sun. Works only if (18) Dynamics - View from a planet has been selected.

(22) Dynamics - Pause
Pauses the movements of the planets. Click again to resume orbiting.

(23) Dynamics - Show paths
When clicked the planets are rendered as points and reveal their orbits as these undergo changes. The paths' width can be changed in Main window → Settings and operations → Planets defaults → Select width of planets path during the operation. Depending on the monitor's resolution during anti-aliasing the width may have to be increased to make the paths visible.

(24) Dynamics - Central force field strength
The gravitational force field of the sun. Can be changed during operation. Increasing its value will exert a greater pull on the planets (subject to their distance) and hence tend to increase their orbital velocity.

(25) Dynamics - Planets force fields strength
The gravitational force field of planets. If (5) Planets - Custom setup has been selected as well as (10) Planets - Special positioning, the value applies to the group identified under (7) Planets - Group. A fainter version of its colour will surround the slider.

(26) Dynamics - Speed factor for planets
The factor participates in the calculations of the velocities of planets as they orbit. It is a once-only addition as the slider is moved. Therefore, while the factor as such matters, it will be overtaken by ongoing developments.

(27) Dynamics - Apply always
The Speed factor is always applied, whether the slider is moved or not.

(28) Dynamics - Slow down frames
Often the planets move so fast, a developing conjunction is hard to spot. Slowing down the frame rate makes it easier. Note: it does not influence the calculations occurring at each frame.

(29) Dynamics - Reset sun + planets parameters
Clicking the button will reset the sun and all the planets to their initial parameters, including the sun's original mass and position.

(30) Dynamics - Reduce planets to initial number
Perhaps the number of planets has increased because of the action by the user, or due to fragmentation (once clusters collide with each other the increase can be quite substantial). Clicking that button will bring the numbers back to their initial value, as well as re-establish a reasonable frame rate.

The following hotkeys only apply if the Planets window is in focus.

(31) Hotkeys - Esc
Stops, then closes the Planets window. Any parameter values derived from the operation will be lost.

(32) Hotkeys - S
Stops the operation and resets the scene to the starting position (the planets are removed from the scene). If (5) Planets - Custom setup has been checked, the planets also go back to their starting position but will be visible in the scene because that's how they appeared at startup.

(33) Hotkeys - Ctrl+S
Fast-save the current scene to file. Includes all the parameters and positions of planets and star/s. The basic file name can be defined in Main window → Settings and operations → Planets defaults → Fast-save files stored as. With every press of the Ctrl+S hotkey the number appended to the file name will be incremented automatically. For example, if the basic filename is C:\AAA\CFTest, then any fast-saves will create files named CFTest_0000, CFTest_0001, CFTest_0002, etc. in C:\AAA.

(34) Hotkeys - P
Ejects a planet from the launcher. Can be done any time during operation. However, the operation must have been started via the F1 hotkey in case of a custom setup, otherwise the planet will just sit at the launcher. Note: the launcher itself is a separate object at the bottom centre of the window and is not included in the camera perspectives. For example, if zoomed out the location of entry into the scene from the launcher will be that much further away, even though the launcher is still at the bottom centre. The same applies to changing the viewing angle: the launched planet may be outside the scene as the camera sees it and will only become visible once it has entered the camera's frustum.

(35) Hotkeys - D (or 1+D, 2+D, ...9+D)
1+D, 2+D etc will delete 1 or 2 etc planets from the scene (maximum is 9), whereas D by itself will delete approx. 4 planets. The latter can be useful if several fragmentations resulted in too many planets and their numbers need to be reduced quickly.

(36) Hotkeys - F1
Starts the operation if (10) Planets - Special positioning has been selected, or if the setup comes from a file and (1) Start with movements has been ticked. Note: no additional planet can be launched unless F1 has been pressed.

(37) Hotkeys - C
Creates a sun from a planet. The planet now has the same mass and size as the sun at that moment. Its trajectory parameters are not altered at that point but will be influenced from now on given the new mass. The first planet of the set on the screen is transformed, and if groups have been defined the first planet of the group selected in (7) Planets - Group will be transformed. When C is pressed again the second will be transformed, and so on. If there are no more planets in that group the hotkey will have no effect (in that case, choose another group).

(38) Hotkeys - B
Turns a planet from a sun back to the previous planetary state. If groups have been defined, one planet/sun after another of a certain group will be changed back again with every B press until there are no more planet/suns left.

(39) Hotkeys - L+Arrow keys L/R/U/D
Rotates the launcher at the bottom centre of the Planets window, to the left, right, up or down.

(40) Hotkeys - G+Arrow keys L/R/U/D
With groups defined the group selected under (7) Planets - Group can be moved left or right, up or down. Must be done before F1 (start) is pressed.

(41) Hotkeys - G+Page keys U/D
With groups defined the group selected under (7) Planets - Group can be moved away from or towards the viewer. Must be done before F1 (start) is pressed.

(42) Hotkeys - V+Arrow keys L/R/U/D
Rotate the viewing angle of the camera left, right, up or down. For example, when rotated 30° to the left, an object will appear as if it had moved to the right if in front of the centre and to the left if behind the centre. The centre itself is not affected.

(43) Hotkeys - V+S
Resets the viewing angle to 0° in all directions.

(44) Hotkeys - Z+Arrow keys U/D
Zooms in or out of the scene. Does not work if (17) Dynamics - View from the sun or (18) Dynamics - View from a planet has been selected.

(45) Hotkeys - Z+S
Resets the zoom distance to the default value of 400.

Planets window

The image shows a 640 x 480 window with a red and a green group, both having 6 planets, to the left and right of the sun, at startup. The viewing angle was rotated 19° to the left, and the scene was moved closer to the viewer from 400 to 238. The launcher can be seen at the bottom centre, pointing slightly to the right and upwards. The F1 hotkey had not been pressed and so nothing moves.

In order of appearance, left to right:

(1) In use
The first number indicates how many planets are in the scene, the second the initial number of planets as defined in Settings. The first number changes when planets are added or removed.

(2) View L/R
Shows the left or right viewing angle in degrees. The default is 0° in both directions.

(3) View U/D
Shows the up or down viewing angle in degrees. The default is 0° in both directions.

(4) Zoom I/O
Shows the viewing distance; ie, the distance from the camera to the centre (the position of the sun at startup). The default is 400.

(5) FPS
Frames per second.

Planets defaults window

In order of appearance, left to right, top to bottom:

(1) Fast-save files stored as
Choose the folder and the basic file name for fast-saves. Stores all the parameters and positions of planets and star/s. With every press of the Ctrl+S hotkey the number appended to the file name will be incremented automatically. For example, if the basic filename is C:\AAA\CFTest, then any fast-saves will create files named CFTest_0000, CFTest_0001, CFTest_0002, etc. in C:\AAA.

(2) Reset file counter to 0
Consecutive numbering of fast-save files start with 0 again. When the file number has reached 9999 the reset occurs automatically.

(3) Select window size
Available sizes range from 320 x 240 to 1600 x 1200 (4:3 format), and from 320 x 180 to 1408 x 792 (16:9 format). Note: the Planets and Spheres windows can also be resized using the mouse during operation.

(4) Include Spheres window
Check the box if the Spheres window should be set to the same size as the Planets window.

(5) Set initial number of planets
The number that should appear in (3) Planets - Initial number of planets at the start of the program. It is only a reference value, planets can be added or removed regardless.

(6) Select default colour
If the planets' colour has not been defined specifically, then that's their colour from now on.

(7) Reset to original colour
Resets the default colour to .

(8) Select width of planets path
Sets the paths' width (can be done during operation), if the (23) Dynamics - Show paths button in the Settings window has been clicked. Depending on the monitor's resolution during anti-aliasing the width may have to be increased to make the paths visible. The initial value is 2.0.

(9) OK
All settings will be stored to file and apply from now on. Closing the window using the X on top right will not store the settings.

© Martin Wurzinger - see Terms of Use