From Maya to Blender

Support Particles and Physics Simulations
#1

Hello all.

for the last 8 years, im working on Maya.
My company simulate mainly car accidents for court, and now we’re going deep into ballistics and crime scenes.
I start thinking a few month ago about moving to work with Blender, and i even got to play with it a little, but before i’m doing the move, i have a few questions, and i’ll be glad if you can help

  1. How accurate can be the physics within blender ? can i control forces over a bullet coming out of a gun ? can the same forces effects on a particles smoke/dust/fire ?

  2. Is it possible net rendering on 2X osx and 1X ubuntu pc ?

  3. Can i skip After Effects and composite withing Blender, including titles, videos and photos ?

  4. Is it possible working 3 machines from one shared network hard drive ?

  5. how convenience working with soft bodies, particles and dynamics ?

  6. can i measure ? can i render the measure it self ? can i do it on a separate layer ?

  7. Is there any plugins for physics forces ?

Thanx for helping
Erez

#2

seems you want to move to houdini instead… lol.

Almost everything is possible in blender, but almost nothing you do by pushing one single button. :wink:

#3

thanx maX,
and if you mention it, with Maya i’m writing scripts for some of the animation, you know, to connect channels of different objects.
is it possible with Blender also ?

Thanx
Erez

#4

hi, i’ve been working in maya also for years, but for home use i’ve been mostly on blender since the interface change a couple of years ago. What’s the name of your company by the way? I knew there were companies that used 3d to deal with that sort of thing but i couldn’t name any.

The thing to note about blender is the release times of the updates to blender are little and often (sometimes not so little to be fair, especially with the recent additions).

Although i haven’t set up everything in your list i do believe it is all possible.

I haven’t used much of the maya particle system by comparison i’d love to hear more about how accurate you can get that for the situations you need.

I’d probably recommend getting a coder on board to help customise your workflow a bit for certain things. Similar to how there are separate branches for certain medical visualisations, i imagine the types of physics you may require might need that sort of level of interactivity under the bonnet.

That is the flexibility of blender though, the code is out on view, it’s open source after all!

#5

Aidyfuzz

I had a company named Art-Kit in Israel, now after leaving my partner and the company, i started a new one called eb3d.
for the last 5 years i did car accidents, accurate by investigator reports and sketches, also by time, speed, distances, lights and so on.
it is working for the court here well and it explains the judge how things happened.
Now i’m taking it step forwards with the Israeli forensic dept’, trying to build fire arms simulations according to high speed cams videos. i’m hoping Blender can be the tool for simulating it.

#6

Oi mate,

I’m in Maya & AE professionally and Blender for interest/hobby. Here’s my input…

You will not get physically correct physics in any of these packages - including Houdini. These applications are all made for visual simulation, not physical realism, even though the back end formulas are physically corrent.

Yes but it’s not worth it. AE is way ahead for motion graphics. It’s possible, but in no way a practical solution for professional work.

Not as simple as in Maya even though some parts are way simpler. The big Issue I have is that you don’t have a unified physics system in Blender where you have 2 in Maya.

#7

Im not expert in animation because Im a modeler, bytheway, interesting discussion :slight_smile:

#8

Yeah, you can do pretty much anything in blender. And, if you know python (which I don’t) I hear it’s easy to script in it. But as MMAaXx said, it’s easier in other programs. Blender, though it does have a good fluid dynamics, physics, fracture, and smoke engine, it’s better for artistic cgi/animations/games.

#9

Im supprised that the court considers rendered video to be admissible documentation. It would take little effort for the opposing counsel to discredit the accuracy, as stated earlier. In the US once your evidence is discredited it becomes worthless, a risk like that makes it a bad investment for a legal firm.

When it comes to physics you should use an actual physics simulator. The company that I used to work for used an actual physics simulator to calculate physics for design application. Then in some instances they would use the exported data to make shapekeys and animate scenarios like this one.

If there’s money riding on it, you should use the real thing.

#10

This animation looks great.
My goal is to take expert’s reports and conclusions and convert it to visual for better understanding.
My works showed at the supreme court and pass 3 judges. so here it’s part of the process.
it is obvious that the work must be side to side with car accident investigator, and he must sign on the video.
Here is an example, sorry for it is not in English, but you can understand from visuals (no sounds).

Can you help me with the name of the software for the physics calculations you’ve talked about ?

Thanx
Erez

#11

In US the courts love to make the jury decide what’s what, but this makes the jury system VERY scary imo as people in general (as in a jury) don’t really care what’s ‘documentation’ and what’s ‘visual aid’ - they could actually treat them equally, kinda like the CSI-effect… This, as stated above, makes US courts VERY scary… ;D

BUT… I think the legal system in Israel are more like the Swedish one where the court would do a better job viewing such a video for what it is, a visual aid, but not view it as evidence without scientific testimony supporting the video… (though I might be wrong :D)

Blender is far from alone in that. 3DS, Maya, Houdini, these are all VFX packages and there’s no interest from the developers in making them physically more exact than to fool the eye… CATIA though, there you can do actual simulation, if you got cash to rent some CPU-time from Amazon… ;D

The animation in your link there is as simple to do in Blender as in Maya. The motion graphic part, in my opinion there’s just no substitute for AE (or Apple Motion) in creating that kinda thing… But for a free app, you could use Libre Office Impress and then convert the flw to a video format, and cut it all together in a NLE like Lightworks, but that’s (imo) VERY limited solution… But free. ;D

#12

(sry - doublepost)

#13

The animation is simple, but the important part is the measures, timing, speed…
it is backed up by scientific testimony as you said and the main purpose is to make judge understand the “crime scene”.
no post production qualities are necessary here.
I know maya and blender can perform it as it looks right now, but i’m aiming to scientific real crime scenes, guns and so.
This i understand non of this 3d software can give me by physics animations.

Thanx
Erez

#14

As for physical accuracy… you code it yourself, a local universe, there’s no need for a universal physics simulation IMO.

Let’s say you got a bullethole in a concrete wall and an impact trajectory with an impact channel depth.
Based on the depth, gauge and type of projectile you can calculate the speed of impact based on the depth of the impact channel.
Based on the projectile you know the muzzle speed of the projectile, based on the rifling of the barrel you can even guess the weapon, and with the impact velocity you can pretty much calculate the distance from the muzzle to the point of impact.
Everyone with a mediocre school education should then be able to calculate from that back to the ballistic trajectory.

This should be very much doable with a python addon, even visualize the flight of the bullet.

OOTB is a no go, but with some efford you could very much make Blender a ballistic analyzation tool.

And I wouldn’t be surprised if there’s a python library somewhere out there already able to do exactly this. All that’s left then is to wrap an UI around it and link the calculated data to objects.

Car accidents on the other hand are quite tough to calculate accurately… not impossible though.

If you have all the data though from a scientific analysis already, just to visualize it should be no big problem at all.

So:

  1. Should be answered with the wall of text.
  2. Yes. There are many network rendering possibilities for various render engines working with Blender.
  3. Yes. Not as comfy as AE IMO, but yes.
  4. (<- again lol) I guess if someone opens the file it’s flaged locked and no one else can write to the file, but everyone in the network should be able to open the file.
  5. Convincing…? Sufficiently. Completely accurate? Not too sure.
  6. You can set Blender to work with generic units, set 1 generic unit to 1 metric unit, or 1 imperial unit. Measurement works in Blender, but could be a lot better.
  7. Not that I am aware of, but you can always grab the source and add something with C/C++ or script either in a .blend or as addon with python. Blender itself uses the “bullet physics engine” but not in the viewport, just in the game engine, where you can record the simulation to animation curves.

But who knows, I think it’s a hot GSOC project to integrate the new OpenCL accelerated bullet engine or any other GPL engine and make it work in the viewport to have one solid foundation for all the simulations within Blender.

#15

Moved from “General Forums > Blender and CG Discussions” to “Support > Particles and Simulations”