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Thein Win

Galaxy

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Hi, this is my first post.

So let me quickly introduce myself. I am from Burma. Currently studying VFX in the UK at the University of Hertfordshire. 

Rite now I am working on my final year film project. In the film I have lots of different particle effects. One of them I am struggling to get at the moment is a galaxy. I have tried many different ways but none of them seem to be looking very nice.

 

Image I have attached below is from the breakdown of documentary Cosmos. I really like how it is looking with the spiral and particles around. So can anyone please help or guide me to achieve something like that. I have tried with trail sop and applying polywire and converted into volume and scatter points. But is still not getting the spiral look.

 

I have only been using Houdini for three months. So still learning. 

 

Thank you.

 

post-15440-0-43567300-1454118658_thumb.p

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you can use the  "goldenspiral" and emit points from them, i made it with Arrays but there should be some posts about it on the sidefx forums and here,

 

a tutorial from adam is on cmivfx

 

maybe helpful  

 

http://www.toadstorm.com/blog/?p=255

http://forums.odforce.net/topic/11780-creating-a-nebula-simulation-from-a-photograph/

spiral.hipnc

Edited by deniz
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When someone says that they are making a Galaxy in 3D, only one thing comes to my mind. Good luck with your project. 

Sorry can't help you more with this. :)

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Thx for the reply. I have gone through the tutorials and links you all have given to me. They are quite helpful. I will soon be start working on it and hopefully will also upload up on this page to get some feedbacks.

 

If any of you have anything related to galaxy or nebula, and particles or krakatoa like effects done in houdini please share me videos, files or links. It will be so nice. 

 

This is the link to my film project work thread - 

 

http://www.3dhit.co.uk/index.php?showtopic=27778

 

please go through it if u have time

 

Type of effects I want to achieve - https://vimeo.com/106800693

                                                       https://www.youtube.com/watch?v=JHRiaKEYeis

 

Thank you so much

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Hacky attempt based on that BUF video. Also tried throwing together a quick attempt to copy galaxy and star sprites onto the shape (and abuse the OGL viewport stuff to make them additive), sorta works, sorta doesn't.

 

Anyway, might give you some ideas.

 

galaxy_v01.hipnc

 

post-7292-0-83620300-1454373526_thumb.pn

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Hi I haven't touched the galaxy for a while and now I am back. I want to continue improve. Need Help!

Below I have attached four pictures. The first one is what I have done so far. 

The rest three is what I am aiming to achieve. What I have done is more like a base. So rite now I want to add some more elements to it. 

As you can see in those pictures there are layers of particles, which I have kinda done, and smoke or gas and those pinkish nerves like gas. Can anyone please help me on how to get those nerve like pink gas as you can see on the pictures. I am not so good with pyro stuff. 

 

The rest three pictures are from Cosmos documentary

 

I really want the quality just like those from the pictures.

I have also provided my hip file. Could you please look inside and see how else can I improve my galaxy.

 

Thank you so much! :)

 

 

 

 

 

 

post-15440-0-79205900-1457909690_thumb.j

post-15440-0-68550000-1457909799_thumb.p

post-15440-0-99813100-1457909832_thumb.p

post-15440-0-32084000-1457909934_thumb.p

Pink_Galaxy.hipnc

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Hi Thein,

 

I hope you have had some more luck with this galaxy that your trying to create. Unless you need to see large dynamic motion in your shots you could generate this volume procedurally through some VOPS potentially. Here is a hip file which has something started in it along these lines, it's currently all math driven but I'm sure you could find some ways to control it nicely. For the final render I would lean towards doing the same operations but inside a volume procedural so that your not limited in resolution.

Hope this helps.

Cheers 

Jake.

 

 

galaxyVolumeSwirl.hipnc

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If you need galaxy formation in time and you have a lot of computing power you can use NBody sim solver with real phisical parameters to generate galaxy. In attached scene there is only 65K points. For more realistic results you probably need several millions of them. NBody sim is done inside loop of POP VOP (Houdini guys it would be nice if someone code it to run on GPU and include it in new release of Houdini as NBody solver).  In the attached scene, period of several billions of years is scaled to several hundred frames. A few parameters control whole sim, time step, cluster scale, velocity scale, drag, etc. Nice thing with this method is you don't have to worry about collisions of two or more galaxies :) (There is not enough computing power on the world to calc that :) ..... ) Seriously... take another sphere inside same SOP and generate point cloud on it like it was done with first, move it on the scene several units away of the first one by transform SOP, merge those two point clouds and connect it in pop network.  

After merge it is actually single point cloud but some points have offset in space. Run sim and enjoy in spectacular two galaxies collision. They will merge eventually in time (and space).

 

https://mega.nz/#!3JwhhZoZ!X6WJn9dPvxUAC2BqwbD1KevluzzRa5Nt1Nm3DAguIz8

 

 

When you get desired look, convert that point cloud in volume and you are done.

Cheers

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Wow, thank you everyone. You guys are amazing. After looking into some of the techniques you all have suggested I think I am going to go procedurally, like Jacob suggested. I think it works really well since is faster to generate and my galaxy wont be in motion.

 

Once again thank you all for taking time to help me out. :)

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im in a project where i have to do a galaxy  too,  i did some tests,  lemme se what i have so far on that matter

Edited by dyei nightmare

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Thx Iskander. Really nice job.

I've got 1.4 FPS on my laptop with your original scene (without trail node calculation) and decide to do optimization of kernel code with some tricks and reached to 3.4 FPS (2.5 times faster). What I did is:

- moved calculation of softening_squared outside of kernel so it is precomputed once and passed to kernel

- removed double index and multiplication of second index for proper position in float3 array by

using vload3 and vstore3 to fetch and store vector data from GPU memory to register and vice versa

- used optimized vector routines in calculus instead calculating values per each vector component

- provided extra arrays to store newpos and newvel vector values and

- used them in writeBack kernel to store values back to attributes instead of using extra pointwrangle node

 

 

Here is modified version

nbody_opencl_modified.hipnc

 

Cheers and thank again

 

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On 2017/11/21 at 6:29 PM, Brazen said:

Just came across a website of a vfx artist, name's Teun van Der Zalm. He creates beautiful nebulae inside Houdini, check it out, it's very inspirational :

https://vimeo.com/teunvanderzalm

 

664479367_1280x720.jpg

it's realy beautiful but ~how to do it~?

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On 16/3/2016 at 7:13 PM, djiki said:

If you need galaxy formation in time and you have a lot of computing power you can use NBody sim solver with real phisical parameters to generate galaxy. In attached scene there is only 65K points. For more realistic results you probably need several millions of them. NBody sim is done inside loop of POP VOP (Houdini guys it would be nice if someone code it to run on GPU and include it in new release of Houdini as NBody solver).  In the attached scene, period of several billions of years is scaled to several hundred frames. A few parameters control whole sim, time step, cluster scale, velocity scale, drag, etc. Nice thing with this method is you don't have to worry about collisions of two or more galaxies :) (There is not enough computing power on the world to calc that :) ..... ) Seriously... take another sphere inside same SOP and generate point cloud on it like it was done with first, move it on the scene several units away of the first one by transform SOP, merge those two point clouds and connect it in pop network.  

After merge it is actually single point cloud but some points have offset in space. Run sim and enjoy in spectacular two galaxies collision. They will merge eventually in time (and space).

 

https://mega.nz/#!3JwhhZoZ!X6WJn9dPvxUAC2BqwbD1KevluzzRa5Nt1Nm3DAguIz8

 

 

When you get desired look, convert that point cloud in volume and you are done.

Cheers

@djiki Hello, I've been trying to simulate something like this and export as vdb. This simulation is perfect for what I need, but is non-commercial. Is there any posibility I can get or buy you the commercial file? It would be very helpfull.

Thanks!

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