No description
dba02e35d4
FG_ENABLE_MULTIPASS_CLOUDS must be defined to enable
the algorithm. I made this because the stencil buffer
must be initialized at the beginning of the program and
OpenGL can fallback to software rendering if it can't
find a visual with stencil buffer. I didn't touch the
configure script, so CXXFLAGS=-DFG_ENABLE_MULTIPASS_CLOUDS
must be set before running ./configure.
If FG_ENABLE_MULTIPASS_CLOUDS is defined, the main render
loop begins by reading the /sim/rendering/multi-pass-clouds
property. It is a boolean property so there are only two
quality levels. false means no multi pass and no use of
the stencil buffer, true means an additionnal pass for
both upper and lower cloud layers.
The algorithms are as follow :
/sim/rendering/multi-pass-clouds=false
1. draw sky dome
2. draw terrain only
3. draw clouds above the viewer
4. draw models except the aircraft
5. draw clouds below the viewer
6. draw the aircraft.
The cloud rendering doesn't update the depth buffer.
This means that models overwrite clouds above the viewer.
This is only noticeable for tall buildings and when
flying very low. Also, drawing low clouds after models
means that they are not blended with models' translucent
surfaces. Large transparent area require alpha test
enabled and AI aircraft canopy are making holes. The
pilot's aircraft being rendered at the end, there is no
problem with canopy or prop disc.
/sim/rendering/multi-pass-clouds=true
1. draw the sky dome
2. draw the terrain only
3. draw all clouds
4. draw models except the aircraft
5. redraw the clouds where the models where drawn ( stencil
test on )
6. draw the aircraft
The assumptions made by this algoritm are that the terrain
is not transparent ( should be true in all cases and
that there are no clouds between the aircraft and the viewer.
Assuming these facts, there should be no blending bugs.
The screenshot rendering is not updated yet.
|
||
|---|---|---|
| docs-mini | ||
| man | ||
| package | ||
| scripts | ||
| src | ||
| tests | ||
| utils | ||
| .cvsignore | ||
| acinclude.m4 | ||
| am2dsp.cfg | ||
| AUTHORS | ||
| autogen.sh | ||
| ChangeLog | ||
| configure.ac | ||
| FlightGear.dsp | ||
| FlightGear.dsw | ||
| Makefile.am | ||
| NEWS | ||
| README | ||
| Thanks | ||
Welcome to the FlightGear Flight Simulator project. =================================================== The primary web page for this project is: http://www.flightgear.org For basic installation instructions see the "INSTALL" file. Before you can run FlightGear you will also need to download and install the "base" package which is a collection of textures, sounds, sample scenery, and other data files need by the sim. For additional install help for specific platforms please browse the "docs-mini/" subdirectory. More complete documentation is available from our web page as a separate distribution. Please take a look at the "Thanks" file for a list of people who have contributed to this project. If you have contributed something but don't find your name in this file. Please send a polite reminder to curt@flightgear.org For a summary of changes/additions by version see the "NEWS" file. This project is GPL'd. For complete details on our licensing please see the "COPYING" file. For information on available mailing lists, mailing list archives, and other available source code and documenation, please visit our web site. FlightGear is a product of the collaboration of large international group of volunteers. FlightGear is a work in progress. FlightGear comes with no warrantee. We hope you enjoy FlightGear and/or find it of some value!