June 2010
2 posts
WatchPart 2 of 2. Pretty much the rest of the playblasts I can find around the lab. Chronologically, the destruction playblasts come after these.
WatchPart 1 of 2 - not sure if this will still be considered but it’s from ages ago, decided I should probably upload it all.
These are a few tests from the window scene, I was attempting to make a smoke plume for the windows - I couldnt quite nail it with forces, uniform fields were only working to a certain extent…
May 2010
19 posts
WatchSomething went wrong somewhere…
WatchMore fun and games…. about 8 hours ago. Procrastination?
WatchFun and games with fluids
WatchOh… and another motion tracking test. Couldn’t get it to track this one in 3d, which was concerning - I think the motion blur in faster frames throws it off, which means either hand-tracking, high frame rates or high shutter speeds.
Will probably just fake most of the handheld-ness with wiggle expressions in post… but maybe a few for real.
WatchSomething thats been annoying me in the background -DoF in post.
Turns out it’s just a custom shader you can assign to a new renderlayer - then you can just render it out and use it as a source for your lens blur effect.
As a note - it seems to need a simple matte choker in there to shrink the DoF layer a bit - otherwise there are white outlines in the more distant areas… not too...
WatchMooooore smoke sims.
Sorry about the sims being in different sizes, I’m getting each one from a separate workstation so the perspective window is always slightly different if i’ve modified settings and forgot to hide them in the attr. editor.
I saw a quick demo of someone else’s on Vimeo using surfaces to emit from, so the last test deals with that. I think it’s the right...
WatchThis is after up-rezing the sim - and simply playblasting it.
I can’t seem to work out why, but when pumped through mental ray the sim is somewhat smoothed out - I’m not sure if it’s a lighting, texturing, or rendering parameter issue so I’m just dealing in playblasts at the moment.
The main critique I’ve had is that it seems to fast - it doesn’t dissipate...
WatchSo - Maya fluids. I’ve been working on these for a while but they take forever to playblast, so they’re all on the backburner while I do other stuff.
Ttextured smoke has been a big issue.
Earlier smoke tests using textured opacity maps turned out to be somewhat unrealistic - it seems to be good for stills but not motion, as the map is static and easily visible as a noise/turbulence...
WatchAnother attempt - I’m putting off doing scifi as this is far more interesting!
Slightly better but still jumpy.
From looking at the tracking details this time in MatchMover, it seems as though it’s mostly the bottom details that are screwing it up - the base of the windows isn’t defined well enough for it to track it nicely so the tracking points just jump everywhere. The top...
WatchAnother motion tracking test, this time with 3D tracking on 8 points on a 3D model.
Interestingly enough it’s not quite as good in some respects, as it’s basing it on such a small amount of points - the data is pretty noisy.
That being said, I could simply create some geometry and have it appear correctly in perspective (the camera was oriented at the right angle this time, instead...
WatchMotiontracking test using Alias MatchMover.
Refs for next, 3D motion track:
Window size:
2.07m x 1.21m
Block Size:
.97 x .46m
There’s also a reeeally crude HDRI lighting setup in there, simply using a frame from the video footage. I’ve used a plane to cut off light from the base of the sphere temporarily. I reeeeeeally need to get a reflective sphere for a proper env map!
Glass Tutorial →
Fluid Guide... Very, very useful →
WHERE?!
Still looking for a reflective sphere. Tried junk shops etc. No Dice.
Aaaaahhh
WatchIt’s been a while.
I feel bad.
Here’s an exploding window that I made tonight. Could do with some particles but that’s for your imagination right now =).
Will camera track and composite this tomorrow. Perhaps find a metal globe as well for an HDRI map?
Mint.
April 2010
6 posts
Tutorial Links of Awesomeness
Particle stuff
http://www.thegnomonworkshop.com/tutorials/collision_emission/collision_emission.html
Tons of useful tutorials:
http://www.infinitee-designs.com/Tutorials-Maya-1.htm
Skies!
http://www.1000skies.com/
WatchFountain of debris!
… instanced particles aren’t a problem it seems. Now to get onto scripting their emission.
A different approach
I think I’m going about this slightly wrong - somehow I don’t think the dynamic geometry *can* be translated before simulation - once dynamic, always dynamic.
I’m thinking I’m going to have to use some kind of constrains system to bind hidden shattered pieces together, then release them at a specified frame. As for how to do this…
OR
Mimic the built-in shatter...
WatchI just noticed I hadn’t uploaded this yet - oops.
Looking back on it as well, it does look like polystyrene. Apparently having Maya bonustools with measure.dll lets you automatically assign weights with the scripts I’ve got - will have to get this sorted tomorrow.
WatchOk - so here’s a video of the problem so far.
Essentially I have two versions of the same geometry - one unshattered, one shattered. The unshattered version is unhidden at first, the shattered is hidden.
At frame 30 they swap visibility with simple keyframes in the attribute editor. The shattered version is parent constrained to the unshattered version in order to inherit it’s...
So...
It’s been a while. Epic holidays, but now it’s time to work.
From the looks of things I’m going to have to get into dynamic constraints. The keyframing and modification of these can then be attributed to various stages of the demolition…
I’m currently also starting to try and get to grips with rigging geometry, and showing/hiding it based upon some simple...
March 2010
17 posts
Useful tutorials for Maya Fluids etc... →
A lot of interesting material from this one user - especially regarding workflow and details of the fluids system.
Will have to try it all out when I’m back in Wellington on Tuesday…
Bullet Physics Documentation →
Just came across the documentation for the actual physics engine behind the plugin - Bullet Physics.
According to page 25 Bullet does run @ 60FPS. This would explain the slow-mo playblasts and general wierdness. I’m going to have to either find a way to fix this, or possibly work around it (animating at 60FPS, then converting the framerate in AE afterwards, perhaps?)
WatchDefinite progress today. Things to remember:
Make sure to check center pivots in the Dynamica creation script
Set initial pivot/center points at another frame than 1 to set initial locations. This stops everything jumping to the middle when the sim is reset
Exporting @ 24 needs to be doubled for realistic speed. Need to talk to durgie about this, as it looks best @ 60FPS in realtime.
Air...
Links, research, etc.
Here’s a collection of what I have and am looking at, time to analyze and document it all properly.
Real-world building demolition examples:
Low res videos, but still kind of useful
http://www.implosionworld.com/cinema.htm
Entire article on building implosions - lots of info.
http://www.howstuffworks.com/building-implosion.htm
It seems that large-scale demolition basically comprises of...
WatchYet another bunch of playblasts, this time with a lot more objects.
Some interesting notes for future reference:
The initial state of a poly will be preserved when converted to a dynamica rigidbody. Will have to find a way to stop this
It’s still to slow!
I found this interesting link though, theres some scripts to help out with dynamica:
...
WatchA lot of issues to be fixed, but also some that are resolved. The simple cube falling apart was not previously possible using the Maya engine, so that’s a start.
Some issues I can already see:
Gravity/weight needs serious adjusting
Objects still seem to intersect at points - especially during fast velocities
From other experiments - edges can not touch, making the crack shatter script in...
Plugins...
More efficient shatter script:
http://www.creativecrash.com/maya/marketplace/scripts-plugins/c/fracture—2?os=windows
Might actually buy this, could make life a little easier.
Free Shatter Scripts: (Second looks more reliable)
http://www.creativecrash.com/maya/downloads/scripts-plugins/modeling/poly-tools/c/as_polyfracture/comments#tabs
...
Forum links, Etc...
Small discussion on creating a breaking glass effect, could come in useful.
http://forums.cgsociety.org/showthread.php?t=89530
HDRI Tutorial →
Outlines the process of getting a range of images, creating an HDRI image in PS, and then bringing it into a 3d context.
Will be useful for compositing later…
...browsing YouTube
Existing fluids tests:
Fluid Explosion examples
http://www.youtube.com/watch?v=6L7cNggV0V8
http://www.youtube.com/watch?v=YqItUEUK23E
http://www.youtube.com/watch?v=T8Bizo3QW-s
An example with a quality closer to what I might want:
http://www.youtube.com/watch?v=C0nHmaF5ZPA
-It almost seems to use some sort of 3D mask to create a rapidly generating cloud. Perhaps the cloud could be...
WatchMore dynamics experiments - using the included shatter script in conjunction with default rigid body settings and a gravity field.
Shattered objects can be keyframed to be either shattered or non-shattered - useful for explosions or structural collapses.
HOWEVER:
There are no self-collisions of the objects themselves. Maya’s physics system runs into problems if each piece is set as...
WatchMore initial experiments with Maya’s dynamics system. Simple low-poly, low-object scene. Notes:
Ball rolls awkwardly - needs exploration into friction
Lacks weight - ball moves too slowly down ramp
WatchInitial experimentation using Maya Dynamics to create a simple domino effect.
Notes:
Random generation of forces - dominoes do not fall perfectly. No tweaking needed.
Performance severely impaired after more than about ten rigid bodies (dominoes). Native physics solver may not be appropriate for larger simulations.
Playblast bugs - caused by physics engine?
WatchCollection of current explorations into Maya Fluids for smoke particle generation.
The next set need to incorporate self-shadowing under lighting, these appear too flat.
The shape/quality of the smoke is also inappropriate for a building collapse - it’s too wispy, thin, and lacking volume.
Project Brief →
PDF Link attached.
Experiments, links, etc follow.
Initial Concept
Allright, here we go…
The Initial Idea: Believeable 3D Demolition
My plan so far is to basically use dynamics system(s) in Maya to create convincing demolitions of a structure(s). I hope to take it further than simply having a storm of particles, and actually include the structural failure of the building as it falls down, with glass breaking, concrete cracking, etc.
From some initial...