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Making an Explosion Hole in Stone Wall

Posted: Tue, 23rd Jun 2009, 2:04pm

Post 1 of 17

Kirkeric

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Hello,

Has anyone seen a preset for something like this? I am blowing a hole through a stone wall (large enough for a human to pass through) and need something to make that look real. This is intended of course to be on a wall that is still intact. smile

Also, if it matters, the view of the wall is not direct on so it is really just a portion of the left side of the hole that would show.

Appreciate the help.

Eric
Posted: Tue, 23rd Jun 2009, 4:27pm

Post 2 of 17

Terminal Velocity

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This is just off the top of my head, but I would guess the easiest way to do that would be to make a clay model of a wall with a hole, then composite it onto the real wall. You could also use 3D modeling (done in NightCast), or of course actually blow a big hole in the wall. Could also build a set piece.
Posted: Tue, 23rd Jun 2009, 4:36pm

Post 3 of 17

Kirkeric

Force: 1000 | Joined: 19th Sep 2008 | Posts: 13

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Thanks. My initial thought is pretty close. I was thinking of modeling a piece at smaller scale and since it is a static shot, just shooting a still on green screen. Then mask out a portion of the original wall and slide that behind or perhaps just right on top if green screen works well. I want to avoid getting additional software so I want to be able to do it using just Visionlab Studio. Blowing a hole in the actual wall isn't an option. smile Though it would be fun.

Eric

Richard III wrote:

This is just off the top of my head, but I would guess the easiest way to do that would be to make a clay model of a wall with a hole, then composite it onto the real wall. You could also use 3D modeling (done in NightCast), or of course actually blow a big hole in the wall. Could also build a set piece.
Posted: Tue, 23rd Jun 2009, 5:23pm

Post 4 of 17

spydurhank

Force: 1956 | Joined: 24th Jun 2008 | Posts: 1357

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You can do the same thing using a photo editor...
Do you have Photoshop Corel or Gimp?
Posted: Tue, 23rd Jun 2009, 6:08pm

Post 5 of 17

Kirkeric

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No, I don't have either of those. What did you have in mind though?

Long time no see. I believe you helped me back in March or so.

Eric


spydurhank wrote:

You can do the same thing using a photo editor...
Do you have Photoshop Corel or Gimp?
Posted: Tue, 23rd Jun 2009, 6:51pm

Post 6 of 17

spydurhank

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Well... you said your shot was static right? No camera movement?

You could easily make a matte painting of a "hole after an explosion" as long as you also have a picture in the same camera angle of what's on the other side of your wall, Behind it that is. That way it'll look better when you composite your live action footage together.

Try and post a pic of your brick wall and whatever is behind it... high res if you can. I'll see what I can come up with and it shouldn't take too long. Maybe 15 to 30 minutes at the most.
Posted: Tue, 23rd Jun 2009, 7:06pm

Post 7 of 17

Kirkeric

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I am posting the video on youtube. Keep in mind the blast needs a bunch of tweaking. It shoots all over the freaking place and I've been trying to adjust a canned one (the Halo Tank Blast, I believe it is under presets). I seem to always have difficulty getting direction right.

If you stop at the 4 and 7 second mark, you can see the wall to the right. You will see it doesn't show much, which was intentional in order to have less to deal with on the hole.

http://www.youtube.com/watch?v=fLPUKzZFxsM

I actually cropped it to show even less but ideally, if the hole can cover up the wooden door edge you see and then sort of go jagged outward a tad to show that side of the hole, it would be fine. I think you will find it easy when you see it.

I will have to send a hi-def still later but to give you an idea.

Let me know where to send it. My email is kirkproductions@gmail.com

Eric

spydurhank wrote:

Well... you said your shot was static right? No camera movement?

You could easily make a matte painting of a "hole after an explosion" as long as you also have a picture in the same camera angle of what's on the other side of your wall, Behind it that is. That way it'll look better when you composite your live action footage together.

Try and post a pic of your brick wall and whatever is behind it... high res if you can. I'll see what I can come up with and it shouldn't take too long. Maybe 15 to 30 minutes at the most.
Posted: Tue, 23rd Jun 2009, 7:15pm

Post 8 of 17

spydurhank

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Right on man.

I'm at spydurhank@hotmail.com

I have to take my sis to the airport right now so I'll be m.i.a. for about an hour and a half but I'll look for your e-mail as soon as I make it back home. Send me some info of where exactly you want the hole to be and I may even be able to send you some pics of splintered wood and bricks that you can import into Visionlab to use in the particle engine for use as flying debris. Cool?
Posted: Tue, 23rd Jun 2009, 7:17pm

Post 9 of 17

Kirkeric

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Hey, great! I appreciate the help. I will shoot that picture off as soon as I get home so that will be right at about 2 hours from now.

I will even send a still shot I had taken before just so you see the whole building and what it is made of.

Appreciate it!

Eric

spydurhank wrote:

Right on man.

I'm at spydurhank@hotmail.com

I have to take my sis to the airport right now so I'll be m.i.a. for about an hour and a half but I'll look for your e-mail as soon as I make it back home. Send me some info of where exactly you want the hole to be and I may even be able to send you some pics of splintered wood and bricks that you can import into Visionlab to use in the particle engine for use as flying debris. Cool?
Posted: Tue, 23rd Jun 2009, 7:49pm

Post 10 of 17

spydurhank

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No prob,
I gotta bolt for now.
Posted: Tue, 23rd Jun 2009, 11:31pm

Post 11 of 17

Kirkeric

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You should have received the emails. I sent a couple hours ago. Appreciate the help.
Eric

spydurhank wrote:

No prob,
I gotta bolt for now.
Posted: Wed, 24th Jun 2009, 12:58am

Post 12 of 17

spydurhank

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Hey,
I just e-mailed the pic to you. Sorry for the wait. Airport, weather plus traffic was pretty bad.
So I used pretty much the same masking that you had for the hole through the wall. The scorching goes a few feet past that slab of concrete and onto the grass. You should notice the difference if you compare the Matte painting with your original.

As I said in the e-mail... I would have preffered to work at a higher res but I wasn't sure what and how the Matte painting would look if you had to scale it down in Visionlab so I worked with the original size.

Let me know if you get the e-mail... I had to send it twice because...? Not sure... puter was acting funny.
Posted: Wed, 24th Jun 2009, 1:09am

Post 13 of 17

Kirkeric

Force: 1000 | Joined: 19th Sep 2008 | Posts: 13

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Frank,

Yes, I've been waiting. Airports are never as planned my man. Take it from me. I travel alot. smile

Any way, I got it and it looks fantastic. Just to restate most of what's in email, I only have one concern and I hope I didn't confuse things. When I said static image, I meant no camera movement but obviously the actor will be moving. So, is this something that I can use and overlay on my video in vision lab?

And I'd definitely love to see some debris too.

Eric


spydurhank wrote:

Hey,
I just e-mailed the pic to you. Sorry for the wait. Airport, weather plus traffic was pretty bad.
So I used pretty much the same masking that you had for the hole through the wall. The scorching goes a few feet past that slab of concrete and onto the grass. You should notice the difference if you compare the Matte painting with your original.

As I said in the e-mail... I would have preffered to work at a higher res but I wasn't sure what and how the Matte painting would look if you had to scale it down in Visionlab so I worked with the original size.

Let me know if you get the e-mail... I had to send it twice because...? Not sure... puter was acting funny.
Posted: Wed, 24th Jun 2009, 1:42am

Post 14 of 17

spydurhank

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I just checked out your clip again.
If you move that explosion more to the right, it'll hide alot of the area that you need to mask out. For the second shot you only need to mask out part of the legs.
Posted: Wed, 24th Jun 2009, 1:57am

Post 15 of 17

Kirkeric

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Yeah, I have some more work to do on the explosion.

Are you suggesting that I just dont show his legs at all until he runs off? Right now the bottoms of his legs are covered up to the calf or so. I may not entirely understand what you mean about masking his legs out.

Thanks,
Eric



spydurhank wrote:

I just checked out your clip again.
If you move that explosion more to the right, it'll hide alot of the area that you need to mask out. For the second shot you only need to mask out part of the legs.
Posted: Wed, 24th Jun 2009, 2:19am

Post 16 of 17

spydurhank

Force: 1956 | Joined: 24th Jun 2008 | Posts: 1357

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When you have both clips on the time line...
Take note of how far the Matte painting reaches as this will cut down on rotoscoping. Temporarily shut off the Matte painting so you only see the actor layer. Use the freehand masking features on your original clip.
1.

This will seem weird at first but there's a reason. Mask each leg, individually for better results. And his torso if you need to. Get in as close as you can with the masks and feather them by 2 or 4. Once your actor is not being blocked by the Matte painting you can move the masks off of the canvas so they wont be in the way.

2.
Copy and paste the mask attributes from both of the legs that you just masked onto the Matte paintings mask features. This will bring all the keyframe data onto the Matte painting. At this point all you will see are empty spaces where your actors legs should be but that's okay. The next step will fix all that.

3.
After that just delete the masks from your original actor clip and you should be able to see your actors legs through the Matte painting.

It's weird but without the use of a green screen... This is the only way that I know of, to achieve this effect. Let me know if this helps.
Posted: Sat, 27th Jun 2009, 5:21pm

Post 17 of 17

rayj00

Force: 0 | Joined: 26th Jun 2009 | Posts: 12

Member

Kirkeric wrote:

Hello,

Has anyone seen a preset for something like this? I am blowing a hole through a stone wall (large enough for a human to pass through) and need something to make that look real. This is intended of course to be on a wall that is still intact. smile

Also, if it matters, the view of the wall is not direct on so it is really just a portion of the left side of the hole that would show.

Appreciate the help.

Eric
Maybe check this out for ideas: http://www.angelfire.com/movies/nobudgetsfx/holeinwall.html