Demolition

[Fernee]

I have an assigment, to make a photoreal building demolition... more like a earthquake affecting a building... anyone done that? any advice on this?

[MonroePoteet]

Well, the tools involved with demolishing a building are fairly straightforward, but the "photoreal" requirement increases the complexity of the simulation greatly.

The basic steps are:

1. In Modeler, Build a highly-detailed model of the building to be demolished
   
   • Including walls, floors, windows, doors, interior furniture, structural compoenents (I beams?), etc.
   • I'd put the doors, windows etc. into a separate layer until the walls / floors are Fractured
2. Use Multiply=>Fracture to break up the walls and floors into chunks
3. After fracture, put the windows, doors, etc. back into the fractured building
4. In Layout, specify the Fractured building as a Parts Body (FX Tools tab)
5. Bring in a ground plane, specified as a Static Body
6. Use envelopes to control how long the building stays together (I used variable Gravity)
7. Use Particles and HVs to create dust as the building collapses

For example, here is a *very* quick animation using a simple four-walled building, a Bend displacement modifier to make the building bend back and forth before collapsing, a Noisy Channel modifier on the Camera's X,Y and Z movements to simulate a STRONG earthquake, and particles / HVs to create the dust:







MOV File - Bullet_SimpleBuilding_EarthquakeFracture.mov

The modeling, animation, etc. probably took 40 minutes, but isn't "photoreal" for many reasons: the brick texture on the walls tiles badly; there are no windows / doors or internal structure to the building; the "chunks" of the building created by Fracture would need to be fined tuned, having the bottom chunks be much smaller to show the destruction of the foundation (use geometries in a background Layer); the building does a little "hop" before falling apart (due to an envelope on World Gravity to prevent the building from falling apart prematurely) which I'd just hide with other stuff (cars? a "wainscoating" type structure); the Hypervoxel dust is too homogeneous and too luminous; there are a few pieces of the building which stay airborne (not sure why but would need to be fixed!); etc. etc. etc.

I'd recommend starting with a simple test building and experimenting with Fracture, Bullet and having it fall apart to learn Fracture and Bullet. Then, increase the "photorealism" of the building and experiment with the demolition. Then, add particles and HVs.

Since you call this "an assignment" (for school I assume), I'm reluctant to post the scene / object files - I think it's important to experiment with the various tools (Modeler, Bullet, Particles, Hypervoxels) to learn the various capabilities rather than just duplicating the simplistic setup of this scene, but here are screen shots of the various portions of the simulation. Be sure to look at the filenames of each screen capture for its description.

Very basic four-wall model, simple Cubic Textured with brick image, Whole Building and Fractured layers:



Bullet setup, Parts Body properties and World Gravity envelope (ramp Bullet gravity from 0.0 to -9.8 at frame 41):



Dissolve envelope on Whole Building layer and Fractured Building layer at frame 41:



"Handheld" kind of Camera Motion, with Noisy Channel modifier:



Particle Emitter:





Hypervoxels on Emitter to show dust (Sprite mode):



Note the importance of Envelopes or Gradients on various parameters to make them change over the course of the animation. In my case, I used Envelopes on the World=>Gravity to prevent the building from falling apart prematurely, "stepping" it from 0.0 to -9.8 between frames 40 and 41. As well, I used an Envelope on the Object Properties=>Render=>Dissolve to show the whole, unfractured building as it sways using the Bend displacement modifier before frame 40, then dissolve it between 40 and 41, "undissolve" the Fractured building from 40-41 and let the demolition proceed. I used a Gradient on the Particle Age to increase the size of the Hypervoxels from 10% to 500% to have the dust "swell" as the building collapses.

Anyway, hope it helps! Good luck!

mTp

[jwiede]

Monroe, you really ought to put together some commercial training for some of these scenarios.

[CaptainMarlowe]

Monroe, you really ought to put together some commercial training for some of these scenarios.

Indeed ! I would gladly pay for it.

[MonroePoteet]

OK, thanks! I'll think about it, but it starts to sound like "work" rather than "fun"! As I'm sure you guys know, I'm just a hobbyist and some of the professionals out there probably think "Why did he do it THAT way?" For example, with 20/20 hindsight, I should've used Bullet=>Activation=>Start Sleeping and a Kinetic Body collision object to start the collapse rather than variable Gravity.

RE: "commercial training", are you guys thinking video tutorials on YouTube? Or what's a better medium / venue?

mTp

[jwiede]

OK, thanks! I'll think about it, but it starts to sound like "work" rather than "fun"! As I'm sure you guys know, I'm just a hobbyist and some of the professionals out there probably think "Why did he do it THAT way?" For example, with 20/20 hindsight, I should've used Bullet=>Activation=>Start Sleeping and a Kinetic Body collision object to start the collapse rather than variable Gravity.

Like most other creative endeavors, worrying about others being better or more capable than you usually isn't productive. Just a thought. Your tutorials here are quite helpful, and even if you see ways to do it more efficiently later, that's just an excuse for follow-ups and new techniques (IMO, anyway).

As for the "work" versus "fun" point, far more relevant, and understood 100%.

RE: "commercial training", are you guys thinking video tutorials on YouTube? Or what's a better medium / venue?

YouTube or Vimeo, just depends on the model you're seeking. I think they're both pretty decent, seems like choosing is really more about which revenue model / branding setup better fits your mindset and working style. For generating lots of smaller tutorials, where you might not feel right selling them individually, something like YouTube's "eyeball counting" approach makes more sense, but for longer, more-involved productions you might find something more like either YouTube's or Vimeo's VoD store more appropriate.

Probably worth taking to a separate thread, and asking some others with significant experience to chip in their views (Bryphi, Lewis, Chilton, Kat, RH, etc.). Kat's always looking for new content authors as well, so a discussion there might be generally worthwhile.

[Fernee]

Thanks Monroe, very helpful!!! you really got into this, I followed you steps and getting very nice results on every step. Another thing is, I wrote it wrong, my english is not as fluid for lack of practice, since I´m in Mexico, it´s not an assignment.... it´s a job, and I´m at the initial pre-production stages, fighting to make this "virtual" in Lightwave, because some people in the production crew wants to make it "phisical" with a maquette, thing that seems to me old and obsolete. It´s been a difficult road, but the producer seems to be convinced to do this according to my advice, just the main detail is missing, the cost... so, if any of the proffesionals around know how much could this budget be around, it will be very helpful. I know!! there are many variables to this, just, a round estimation would be very appreciated.
Thanks again.

[stevecullum]

Thanks Monroe, very helpful!!! you really got into this, I followed you steps and getting very nice results on every step. Another thing is, I wrote it wrong, my english is not as fluid for lack of practice, since I´m in Mexico, it´s not an assignment.... it´s a job, and I´m at the initial pre-production stages, fighting to make this "virtual" in Lightwave, because some people in the production crew wants to make it "phisical" with a maquette, thing that seems to me old and obsolete. It´s been a difficult road, but the producer seems to be convinced to do this according to my advice, just the main detail is missing, the cost... so, if any of the proffesionals around know how much could this budget be around, it will be very helpful. I know!! there are many variables to this, just, a round estimation would be very appreciated.
Thanks again.

I did a similar thing a while ago, I spent around 10 days on it I think. So for budget wise, I would quote 10 * daily rate + contingency.

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

[MonroePoteet]

Hi Fernee,

OK on "job" rather than "assignment". Sorry for my misunderstanding!

I've attached the Scene, Object and Image files to get you started (although it sounds like you reproduced it already!). As I said in my previous post, there's a lot of work to be done to make this simple scene into something which would "fool the eye" into believing it was actually photographed with a real camera.

This scene is a little different from what I posted before, although the effect is basically the same. The difference is how the collapse of the building is started. In this scene, Gravity is constant at -9.8 m/s/s, and the Parts Body has its Activation mode set to "Start Sleeping", which means Bullet won't affect it until some trigger occurs. In this case, I created a simple sphere, set its Surface to 100% transparent (or Properties=>Render=>Unseen by Camera and turn off all Shadows), set it up as a Kinematic Body in Bullet, and then keyframed the sphere to *lightly* touch the Parts Body to activate the collapse:

Parts Body Activation is "Start Sleeping"

Hidden Spherical Kinematic Body touches Parts Body to start collapse

You need to have the Kinematic Body *lightly* touch the building because if it has much virtual momentum, it will cause the Parts to "explode upward" rather than just collapsing!

I also forgot to include details on the Bend Displacement Modifier:

Bend Displacement Modifier

When you add the Bend modifier, you also add two Nulls: a "base" and a "handle". You separate these Nulls around the geometry you want to bend (in this case, the Whole Buliding layer), specify the Nulls in the Bend modifier's panel, and then move the "handle" (or the "base") to cause the geometry to bend.

Good luck!
mTp

[prometheus]

I did a similar thing a while ago, I spent around 10 days on it I think. So for budget wise, I would quote 10 * daily rate + contingency.

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

cool...did you use hv´s for that or turbulenceFD?
if the smoke had a little deeper darker shadows or color, and a bit larger noise scale, it would look really nice, and a little faster simulation in speed perhaps, especially the breaking parts..unless it is supposed to illustrate
a a tiny bit of slo mo.

[prometheus]

Well, the tools involved with demolishing a building are fairly straightforward, but the "photoreal" requirement increases the complexity of the simulation greatly.

The basic steps are:

1. In Modeler, Build a highly-detailed model of the building to be demolished
   
   • Including walls, floors, windows, doors, interior furniture, structural compoenents (I beams?), etc.
   • I'd put the doors, windows etc. into a separate layer until the walls / floors are Fractured
2. Use Multiply=>Fracture to break up the walls and floors into chunks
3. After fracture, put the windows, doors, etc. back into the fractured building
4. In Layout, specify the Fractured building as a Parts Body (FX Tools tab)
5. Bring in a ground plane, specified as a Static Body
6. Use envelopes to control how long the building stays together (I used variable Gravity)
7. Use Particles and HVs to create dust as the building collapses

For example, here is a *very* quick animation using a simple four-walled building, a Bend displacement modifier to make the building bend back and forth before collapsing, a Noisy Channel modifier on the Camera's X,Y and Z movements to simulate a STRONG earthquake, and particles / HVs to create the dust:







MOV File - Bullet_SimpleBuilding_EarthquakeFracture.mov

The modeling, animation, etc. probably took 40 minutes, but isn't "photoreal" for many reasons: the brick texture on the walls tiles badly; there are no windows / doors or internal structure to the building; the "chunks" of the building created by Fracture would need to be fined tuned, having the bottom chunks be much smaller to show the destruction of the foundation (use geometries in a background Layer); the building does a little "hop" before falling apart (due to an envelope on World Gravity to prevent the building from falling apart prematurely) which I'd just hide with other stuff (cars? a "wainscoating" type structure); the Hypervoxel dust is too homogeneous and too luminous; there are a few pieces of the building which stay airborne (not sure why but would need to be fixed!); etc. etc. etc.

I'd recommend starting with a simple test building and experimenting with Fracture, Bullet and having it fall apart to learn Fracture and Bullet. Then, increase the "photorealism" of the building and experiment with the demolition. Then, add particles and HVs.

Since you call this "an assignment" (for school I assume), I'm reluctant to post the scene / object files - I think it's important to experiment with the various tools (Modeler, Bullet, Particles, Hypervoxels) to learn the various capabilities rather than just duplicating the simplistic setup of this scene, but here are screen shots of the various portions of the simulation. Be sure to look at the filenames of each screen capture for its description.

Very basic four-wall model, simple Cubic Textured with brick image, Whole Building and Fractured layers:



Bullet setup, Parts Body properties and World Gravity envelope (ramp Bullet gravity from 0.0 to -9.8 at frame 41):



Dissolve envelope on Whole Building layer and Fractured Building layer at frame 41:



"Handheld" kind of Camera Motion, with Noisy Channel modifier:



Particle Emitter:





Hypervoxels on Emitter to show dust (Sprite mode):



Note the importance of Envelopes or Gradients on various parameters to make them change over the course of the animation. In my case, I used Envelopes on the World=>Gravity to prevent the building from falling apart prematurely, "stepping" it from 0.0 to -9.8 between frames 40 and 41. As well, I used an Envelope on the Object Properties=>Render=>Dissolve to show the whole, unfractured building as it sways using the Bend displacement modifier before frame 40, then dissolve it between 40 and 41, "undissolve" the Fractured building from 40-41 and let the demolition proceed. I used a Gradient on the Particle Age to increase the size of the Hypervoxels from 10% to 500% to have the dust "swell" as the building collapses.

Anyway, hope it helps! Good luck!

mTp

Great sharing..

though I see you have 2018...so why not try sending the scene to blender and use fluids for the smoke and debris dust? after simulation send back to lightwave and use openVDB to render with lightwave´s volumetrics.
I think that has a potential to deliver more realistic smoke dust than hv´s today.

[stevecullum]

cool...did you use hv´s for that or turbulenceFD?
if the smoke had a little deeper darker shadows or color, and a bit larger noise scale, it would look really nice, and a little faster simulation in speed perhaps, especially the breaking parts..unless it is supposed to illustrate
a a tiny bit of slo mo.

I think it was one of the first projects I used turbulenceFD on. In retrospect, yeah I would agree the smoke should have had more details and darker generally. I think my model scale might have been a bit off so explosion parts looked slower than it should have in relation to the other buildings and scenery.

[Fernee]

Monroe, Man!!! this is great, really, thanks!!! ...and you already have the material to start a nice tutorial on this, I mean...you should do it, you nail it very nice.
Thanks again, I´m on the right track for this.

[Fernee]

I did a similar thing a while ago, I spent around 10 days on it I think. So for budget wise, I would quote 10 * daily rate + contingency.

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

Hi Steve, the drone anim looks great, did you use HV for the smoke? or Turbulence?
And, thanks for the money rate guide

[jbrookes]

Some possibly useful videos for you:

https://www.youtube.com/watch?v=8MJl0LV_s5c

https://www.youtube.com/watch?v=kOinjz10e5Q

https://www.youtube.com/watch?v=d2uae2DMaQs

Depending on what you end up doing, Chronosculpt might be a useful app as well...

https://www.lightwave3d.com/buy-chronosculpt/