Skip to content

Moved manual to worldengine-data #18

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
esampson wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Moved manual to worldengine-data #18

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
192 changes: 192 additions & 0 deletions manual/Makefile
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,192 @@
# Makefile for Sphinx documentation
#

# You can set these variables from the command line.
SPHINXOPTS =
SPHINXBUILD = sphinx-build
PAPER =
BUILDDIR = _build

# User-friendly check for sphinx-build
ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
endif

# Internal variables.
PAPEROPT_a4 = -D latex_paper_size=a4
PAPEROPT_letter = -D latex_paper_size=letter
ALLSPHINXOPTS = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
# the i18n builder cannot share the environment and doctrees with the others
I18NSPHINXOPTS = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .

.PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest coverage gettext

help:
@echo "Please use \`make <target>' where <target> is one of"
@echo " html to make standalone HTML files"
@echo " dirhtml to make HTML files named index.html in directories"
@echo " singlehtml to make a single large HTML file"
@echo " pickle to make pickle files"
@echo " json to make JSON files"
@echo " htmlhelp to make HTML files and a HTML help project"
@echo " qthelp to make HTML files and a qthelp project"
@echo " applehelp to make an Apple Help Book"
@echo " devhelp to make HTML files and a Devhelp project"
@echo " epub to make an epub"
@echo " latex to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
@echo " latexpdf to make LaTeX files and run them through pdflatex"
@echo " latexpdfja to make LaTeX files and run them through platex/dvipdfmx"
@echo " text to make text files"
@echo " man to make manual pages"
@echo " texinfo to make Texinfo files"
@echo " info to make Texinfo files and run them through makeinfo"
@echo " gettext to make PO message catalogs"
@echo " changes to make an overview of all changed/added/deprecated items"
@echo " xml to make Docutils-native XML files"
@echo " pseudoxml to make pseudoxml-XML files for display purposes"
@echo " linkcheck to check all external links for integrity"
@echo " doctest to run all doctests embedded in the documentation (if enabled)"
@echo " coverage to run coverage check of the documentation (if enabled)"

clean:
rm -rf $(BUILDDIR)/*

html:
$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
@echo
@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."

dirhtml:
$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
@echo
@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."

singlehtml:
$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
@echo
@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."

pickle:
$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
@echo
@echo "Build finished; now you can process the pickle files."

json:
$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
@echo
@echo "Build finished; now you can process the JSON files."

htmlhelp:
$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
@echo
@echo "Build finished; now you can run HTML Help Workshop with the" \
".hhp project file in $(BUILDDIR)/htmlhelp."

qthelp:
$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
@echo
@echo "Build finished; now you can run "qcollectiongenerator" with the" \
".qhcp project file in $(BUILDDIR)/qthelp, like this:"
@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/WorldEngine.qhcp"
@echo "To view the help file:"
@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/WorldEngine.qhc"

applehelp:
$(SPHINXBUILD) -b applehelp $(ALLSPHINXOPTS) $(BUILDDIR)/applehelp
@echo
@echo "Build finished. The help book is in $(BUILDDIR)/applehelp."
@echo "N.B. You won't be able to view it unless you put it in" \
"~/Library/Documentation/Help or install it in your application" \
"bundle."

devhelp:
$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
@echo
@echo "Build finished."
@echo "To view the help file:"
@echo "# mkdir -p $$HOME/.local/share/devhelp/WorldEngine"
@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/WorldEngine"
@echo "# devhelp"

epub:
$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
@echo
@echo "Build finished. The epub file is in $(BUILDDIR)/epub."

latex:
$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
@echo
@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
@echo "Run \`make' in that directory to run these through (pdf)latex" \
"(use \`make latexpdf' here to do that automatically)."

latexpdf:
$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
@echo "Running LaTeX files through pdflatex..."
$(MAKE) -C $(BUILDDIR)/latex all-pdf
@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."

latexpdfja:
$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
@echo "Running LaTeX files through platex and dvipdfmx..."
$(MAKE) -C $(BUILDDIR)/latex all-pdf-ja
@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."

text:
$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
@echo
@echo "Build finished. The text files are in $(BUILDDIR)/text."

man:
$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
@echo
@echo "Build finished. The manual pages are in $(BUILDDIR)/man."

texinfo:
$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
@echo
@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
@echo "Run \`make' in that directory to run these through makeinfo" \
"(use \`make info' here to do that automatically)."

info:
$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
@echo "Running Texinfo files through makeinfo..."
make -C $(BUILDDIR)/texinfo info
@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."

gettext:
$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
@echo
@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."

changes:
$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
@echo
@echo "The overview file is in $(BUILDDIR)/changes."

linkcheck:
$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
@echo
@echo "Link check complete; look for any errors in the above output " \
"or in $(BUILDDIR)/linkcheck/output.txt."

doctest:
$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
@echo "Testing of doctests in the sources finished, look at the " \
"results in $(BUILDDIR)/doctest/output.txt."

coverage:
$(SPHINXBUILD) -b coverage $(ALLSPHINXOPTS) $(BUILDDIR)/coverage
@echo "Testing of coverage in the sources finished, look at the " \
"results in $(BUILDDIR)/coverage/python.txt."

xml:
$(SPHINXBUILD) -b xml $(ALLSPHINXOPTS) $(BUILDDIR)/xml
@echo
@echo "Build finished. The XML files are in $(BUILDDIR)/xml."

pseudoxml:
$(SPHINXBUILD) -b pseudoxml $(ALLSPHINXOPTS) $(BUILDDIR)/pseudoxml
@echo
@echo "Build finished. The pseudo-XML files are in $(BUILDDIR)/pseudoxml."
108 changes: 108 additions & 0 deletions manual/biomes.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,108 @@
Biomes, Temperature, and Humidity
=================================

Worldengine uses a complex system to model the environment. For the ease of use for beginners Worldengine is setup to default to a planet with an ecological balance similar to Earth's.

While the system is technically complex, in that it has multiple integrated parts, it is not terribly difficult to understand. In this document we will first explain the general model used for placing biomes and then explain how the user can alter different variables to produce non-terrestrial planets.

Biomes
------

Worldengine implements a version of the `Holdridge life zones <https://en.wikipedia.org/wiki/Holdridge_life_zones>`_ model for the placement of biomes. While the standard Holdridge life zone model uses three axes Worldengine only concerns itself with the temperature and precipitation axes.

.. image:: images/Holdridge.png
:align: center
:width: 95%

As an example, an area of the planet that is **Boreal** in temperature and **Semiarid** in humidity will be classified as **Boreal Wet Forest**.

While many people regard the |Koppen|_ system as superior it requires the ability to predict seasonal weather. This would require a highly complicated weather simulation system which Worldengine does not currently have. As a result all Temperature and Humidity values are given in terms of yearly averages.


.. |Koppen| replace:: K |o| ppen climate classification
.. _Koppen: https://en.wikipedia.org/wiki/K%C3%B6ppen_climate_classification

.. |o| unicode:: 0xf6 .. Latin small o with diaeresis
:trim:

There are thirty nine different land biomes. Most cells hold a single biome and most biomes occupy a single cell. The notable exceptions are Polar Ice which occupies two cells and the biomes of the **Warm Temperate** and **Subtropical** regions, each of which occupy only half a cell.

Biomes are then grouped into larger and broader categories such as **Ice**, **Tropical Rain Forest**, and **Mixed Forests**. In the image above the various biomes of each category have been color coded and surrounded by thicker lines with a key to the different groups provided in the upper left corner.

Temperature and Humidity
------------------------

As mentioned above Temperature and Humidity are expressed in Worldengine as yearly averages. We do not yet have a complex weather simulating system that is capable of handling seasonal changes.

Worldengine works largely in unitless numbers. What this means is that a value of .5 for something such as Humidity does not mean that it has twice as much water as an area with a value of .25. All that can really be interpreted directly from this number is that it has a greater amount of water, but it is not possible to say exactly how much.

It is the command line options of **--temps** and **--humids** that convert those unitless values into the actual Temperature and Humidity ranges. The way these values work is to define what percentage of the total land terrain is to be considered a certain value or lower (where lower is considered to be either colder or drier depending upon which variable is specified).

As an example the default value for **--temps** is .126/.235/.406/.561/.634/.876. Thus, the first point of separation is at 12.6%. This in turn means that 12.6% of the land mass will be **Polar**. The next point of separation occurs at 23.5% which means that 23.5% of the land mass will be either **Polar** or **Subpolar** (and since 12.6% of the landmass is **Polar** that leaves only a remaining 10.9% to be **Subpolar**).

By altering these values one can make a planet that is either hotter or colder, wetter or drier. A **--temps** value of 0/.126/.235/.406/.561/.634 will result in a planet with no locations with a **Polar** climate and 36.6% of the planet having a **Tropical** climate (as opposed to 12.4% for the default).

Temperature/Humidity Curve and Scatter Plots
--------------------------------------------

One thing that many people may notice in the Holdridge life zones chart given above is that as regions get colder the maximum amount of water that they may receive decreases. If Worldengine were to simply generate values for Humidity independent of Temperature a significant portion of the simulated planet would receive too much average rain fall. While Worldengine is able to handle such an occurrence (it simply treats the terrain as recieving the maximum water possible) this still produces less than ideal results. To correct this problem Humidity undergoes a mathematical transformation designed to produce results more in line with those of a terrestrial planet.

At its heart the mathematical operation is not too complicated. Both Temperature values and Humidity values are normalized to a range of 0 to 1. The Temperature value is then fed into a function that returns a new value that also has a range of 0 to 1. The original Humidity value is multiplied by this number and the new Humidity value is determined.

If we assume for just a moment that the value of **-gv** is 1 then the Temperature function is relatively simple. It is a straight line that runs from **-go** to 1 as Temperature runs from 0 to 1. Thus, on the default settings (**-go** = .2) we would multiply the original Humidity value by .2 when Temperature is 0 and we would multiply it by 1 when the Temperature is 1. If we were to use a straight line (**-gv** = 1) then we would multiply by .6 when Temperature is .5, .4 when the Temperature is .25, etc. We do this because without the offset value (**-go**) we find that we are multiplying by numbers that are too small at the coldest end of the Temperature scale resulting in too much **Polar Desert** terrain.

While this offset gives us better results in the colder ranges we find that unfortunately it has a tendency to push the average rainfall up a bit too much in the middle ranges. In order to correct for this we use the following function:

.. math::
f(Temperature) = Temperature ^{GV}

where "GV" is the **-gv** variable. This is the same basic function that is used in `gamma correction <https://en.wikipedia.org/wiki/Gamma_correction>`_ and so we have appropriated the term "gamma value" and "gamma offset" to describe our variables (although to be technical our function is not actually a gamma curve).

It should be noted for technical reasons that the curve is actually calculated first, then compressed and shifted by amounts determined by the offset variable (**-go**). This means that the value for f(Temperature) will always range from the offset variable to 1.

To ensure that the **-gv** and **-go** variables are producing a good curve it may be desirable to generate a scatter plot when the planet is being created.

.. only:: html

.. image:: images/scatter_plot_example.png
:align: center

.. only:: latex

.. image:: images/scatter_plot_example.png
:align: center
:width: 50%



Each point on this plot is a single point on the landmass of the planet. The Temperature runs across the bottom, ranging from **Polar** to **Tropical** while the Humidity runs along the side, ranging from **Superarid** to **Superhumid**. Lines are drawn to show the dividing point between various Temperature and Humidity ranges. While the current routine does not label the rows and columns the following image is provided to help understand how they correspond to the chart:

.. only:: html

.. image:: images/scatter_plot-labelled.png
:align: center

.. only:: latex

.. image:: images/scatter_plot-labelled.png
:align: center
:width: 35%


Cells in grey are ones which do not technically occur in the standard Holdridge life zone model and as the example above shows there are certain areas of terrain in the example that are both **Polar** and **Semiarid**. Since there are not too many of them we will not concern ourselves as Worldengine will simply treat them as **Polar** and **Arid** (i.e. classify them as **Polar Ice**).

Biome Images
---------

The following is the color key for biome images, both showing the color and providing the hex code for the color:

.. only:: html

.. image:: images/Biomes.png
:align: center

.. only:: latex

.. image:: images/Biomes.png
:align: center
:width: 75%
Loading