Bonsai -- A GPU gravitational [BH]-tree code

Copyright [2010-2012] Jeroen Bédorf [email protected] Evghenii Gaburov [email protected]

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this code except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Bonsai demo keys

• [esc] quit
• [h] / [~] sliders
• [space] toggle simulation
• [r] toggle rendering
• [p] move through particle render modes (volumetric, points, additive point sprites)
• [b] toggle octree boxes
• [l] toggle display light scatter buffer
• [c] fit camera
• [[] decrement minimum octree display level
• []] increment minimum octree display level
• [-] decrement maximum octree display level
• [=] increment maximum octree display level
• [g] toggle glow / post processing
• [f] toggle fly mode (use wasd to steer, right mouse to go faster)
• [n] detonate supernova
• [1] toggle direct (N^2) gravitation

Bonsai Program arguments

Standard:

 -h  --help             Prints this help 
 -i  --infile #         Input snapshot filename 
 --logfile #        Log filename [gpuLog.log]
 --dev #            Device ID [0]
 --renderdev #      Rendering Device ID [0]
 -t  --dt #             time step [0.0625]
 -T  --tend #           N-body end time [1]
 -e  --eps #            softening (will be squared) [0.05]
 -o  --theta #          opening angle (theta) [0.75]
 --snapname #       snapshot base name (N-body time is appended in 000000 format) [snapshot_]
 --snapiter #       snapshot iteration (N-body time) [-1]
 --rmdist #         Particle removal distance (-1 to disable) [-1]
 --valueadd #       value to add to the snapshot [0]
 -r  --rebuild #        rebuild tree every # steps [2]
 --reducebodies #   cut down bodies dataset by # factor 
 --log              enable logging 
 --prepend-rank     prepend the MPI rank in front of the log-lines 
 --direct           enable N^2 direct gravitation [off]
 --plummer  #      use plummer model with # particles per proc
 --sphere   #      use spherical model with # particles per proc
 --diskmode        use diskmode to read same input file all MPI taks and randomly shuffle its positions

Demo specific:

• --reducebodies Cut down bodies dataset by # factor

• --reducedust Cut down dust dataset by # factor

• --direct Enable N^2 direct gravitation

• --renderdev Device ID to run the visualization on

• --fullscreen Set fullscreen mode string, format: [ width "x" height ][ ":" bitsPerPixel ][ "@" videoRate ]

• --displayfps Enable on-screen FPS display

• --Tglow Enable glowing particles @ # Myr

• --dTglow Reach full brightness in @ # Myr

Compile tips and tricks

Using CMake under Linux:

For Demo purposes: cmake -DUSE_B40C=1 -DUSE_DUST=1 -DUSE_OPENGL=1

For production simulations cmake -DUSE_B40C=1 -DUSE_DUST=0

Using MPI under linux: cmake -DCMAKE_CXX_COMPILER=mpicxx

Compilation for Fermi architecture: cmake -DCOMPILE_SM30=0

Compilation for Tesla architecture: Sorry not supported anymore, time to upgrade your hardware!

Compilation with device debugging: cmake -DCUDA_DEVICE_DEBUGGING=1

Build debug configuration: cmake -DCMAKE_BUILD_TYPE=Debug

(Or use ccmake CMakeCache.txt, to alter the properties)