in this case the bulge, within which is the central black hole, is represented by a fixed mass distribution. I did not add any additional effect, all you see in the center is due to differential rotation. This video contains a very simple model of the galactic disk performance without short-range interactions to search for patterns of spiral density and many details of the actual behavior of a galaxy have been overlooked.
=> this creations are very interesting, and even more if you could see them from different views/angles/etc. Moreover, I want to build some configuration like this one (galaxy-like). It's good to read here initial conditions, it's really helpful, and maby soon i'll get somethig like this. Actually my plans are vast and includes writting a raytracer, smoke-render and so on ;) But i think that i will have to buy new card that supports OpenCL, and of course that is more efficient :)
I like this one! Now i'm working in the same field. I have only my ati 3870, so i work with brook plus (it's doesn't support OpenCL). My algorithm is pretty ordinary (all-pairs). I've get about the same perfomance on my card (you said that in this video was 1400 images, generated in 15 minutes, thus it's 1.5 fps realtime) on 32786 particles. Now i want to use OpenGL to render particles (or maby do some calculations for "camera" rotation/moving in the rendered world), because exploring this =>
Could I ask an initial properties of the disk galaxy? Your result is very stable for a long time. If you don't mind releasing a your initial condition of the disk, I'd like to see a initial properties. :)
Hi, I'll try to explain it: This is the result of the simulation of a complex model with three parts: disk, halo and bulge. The disk is composed by 30K particles and for the bulge and the halo I used the gravitional field of two fixed ellipsoids (I mean that the halo and bulge aren't composed by particles,Hockney and Brownrigg, 1974). You can read about this model the book "Computer simulation using particles", Hockney and Eastwood (1989).
Initial conditions: the bodies are placed in the disk using a gaussian distribution, the ratio width/length 5-20, the radius of the bulge is 0.1-0.5 times the disk size, the halo has 1.5-2.5 times the disk size. For the mass, I used 70% for the halo, 15% for the bulge and 25% for the disk. For the speed profile I did the estimation of the equilibriun using the energy of the gravitational field and added a little random speed (with a 0.1%-1.0% of respect to the equilibrium speed).
Making litle changes in the parameters is possible to get differents spiral patterns and get a central bar. By the other hand the number of particles is critical in the stability of the spiral structure, I have never obtained a stable spiral using less than 100K particles. You must understand that is only a model and it has many limitations (for example, the gas component is not included in the simulation)
Well, I did the program, but you can find a similar code in the CUDA examples. The main differences between the codes is that I can change easly the paticle density and speed profiles, I use another numerial integrator and don't use opengl for the partcle representation.
looks remarkably like a galaxy towards the end :)
TheReasonWhyGuy 5 months ago
Is the gravitiy center a stationary dot like a real black hole or does it have a rotating effect added manualy like a vortex?
Altough black holes pull everything in every direction they cause an vortex effect. Is that the case in this video? Or is it added manually.
TheodenN 10 months ago
@TheodenN
in this case the bulge, within which is the central black hole, is represented by a fixed mass distribution. I did not add any additional effect, all you see in the center is due to differential rotation. This video contains a very simple model of the galactic disk performance without short-range interactions to search for patterns of spiral density and many details of the actual behavior of a galaxy have been overlooked.
jahkr 10 months ago
=> this creations are very interesting, and even more if you could see them from different views/angles/etc. Moreover, I want to build some configuration like this one (galaxy-like). It's good to read here initial conditions, it's really helpful, and maby soon i'll get somethig like this. Actually my plans are vast and includes writting a raytracer, smoke-render and so on ;) But i think that i will have to buy new card that supports OpenCL, and of course that is more efficient :)
LSDDao 1 year ago
I like this one! Now i'm working in the same field. I have only my ati 3870, so i work with brook plus (it's doesn't support OpenCL). My algorithm is pretty ordinary (all-pairs). I've get about the same perfomance on my card (you said that in this video was 1400 images, generated in 15 minutes, thus it's 1.5 fps realtime) on 32786 particles. Now i want to use OpenGL to render particles (or maby do some calculations for "camera" rotation/moving in the rendered world), because exploring this =>
LSDDao 1 year ago
Hi, interesting simulation, i like how the galaxy was stable for a long time, did you use any dark matter?
rotgertesla 1 year ago
Yes, the fixed halo and bulge can be considered, for the most part, like dark matter. Thanks for your comment
jahkr 1 year ago
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adrieumoll98 1 year ago
Could I ask an initial properties of the disk galaxy? Your result is very stable for a long time. If you don't mind releasing a your initial condition of the disk, I'd like to see a initial properties. :)
akahard2dj 1 year ago
Hi, I'll try to explain it: This is the result of the simulation of a complex model with three parts: disk, halo and bulge. The disk is composed by 30K particles and for the bulge and the halo I used the gravitional field of two fixed ellipsoids (I mean that the halo and bulge aren't composed by particles,Hockney and Brownrigg, 1974). You can read about this model the book "Computer simulation using particles", Hockney and Eastwood (1989).
jahkr 1 year ago
Initial conditions: the bodies are placed in the disk using a gaussian distribution, the ratio width/length 5-20, the radius of the bulge is 0.1-0.5 times the disk size, the halo has 1.5-2.5 times the disk size. For the mass, I used 70% for the halo, 15% for the bulge and 25% for the disk. For the speed profile I did the estimation of the equilibriun using the energy of the gravitational field and added a little random speed (with a 0.1%-1.0% of respect to the equilibrium speed).
jahkr 1 year ago
Correction: For the mass, I used 70% for the halo, 15% for the bulge and 15% for the disk. sorry
jahkr 1 year ago
Making litle changes in the parameters is possible to get differents spiral patterns and get a central bar. By the other hand the number of particles is critical in the stability of the spiral structure, I have never obtained a stable spiral using less than 100K particles. You must understand that is only a model and it has many limitations (for example, the gas component is not included in the simulation)
jahkr 1 year ago
how did you do this... or is it downloadable?
Duskrunner291 2 years ago
Well, I did the program, but you can find a similar code in the CUDA examples. The main differences between the codes is that I can change easly the paticle density and speed profiles, I use another numerial integrator and don't use opengl for the partcle representation.
jahkr 2 years ago
wow thats really cool... it really acts like the milky way
natethegreatBlitzMax 2 years ago