Ouch…not really

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In this blog I thought I’d continue on some of the techniques used in visual effects.

A lot of effects in movies are actually 2d mapped onto environments or 2d images used to hide unwanted items.  They’re also used to replace things like posters and number plates.

In my last blog I talked about the effects of creating the rabbit, the rabbit was one of the 3D effects in the film.  There aren’t that many 3D effects used in The Great Spielron but I had to use 3D for one of the more gruesome scenes where some of our characters get a knife in their heads.

I’ll break down one of these shots,  it’s where Katie throws the knife and it hits Mike square in the forehead.

When deciding the best approach for an effect I think it’s always best to ask the question “can this be done on set with real practical effects?” If the answer is yes then I always think this is the best approach as it doesn’t matter how good the effect is in CG, it’s never as good as a real prop.

Obviously for this particular shot that required a knife to be thrown, the answer was most definitely “no” we can’t use a real knife…well not unless we didn’t need our actor anymore, but we did so we decided it was best not to really kill him.   So the choice was to do it in CG (computer graphics).

This actually posed a problem when filming, as I realised we couldn’t even use a proxy object when Katie goes to stab Kevin in the head as even something soft like a foam knife would still hurt if it hit you in the eye.  So I had get them to act and react with nothing at all. It also didn’t help that it was about 12:00am and so we had about 10 minutes to wrap up the whole end scene. Everything in that last part of the movie was finished in about 15 minutes.  We just went handheld and tried to get as much shots as we could. Anyway I’m digressing.

Now on a big budget film there would be time set aside for the VFX supervisor to take measurements and measure lighting info, using things like a big chrome ball and a big grey ball.  You sometimes see these on the making of movies.  Basically what these do is allow the VFX artist to work out where the light is coming from and how intense it is.  By taking photos at different exposures they can then put this information into the computer and the lighting they get is pretty accurate to what was on set.  It also allows them to have reflections that match too, so the whole CG elements fit to the environment.

We didn’t have time to do this, I brought the chrome ball but we were so rushed that it never got used, I had to rely on my eyes to try and get the knife to match the real footage as best as possible.

One issue with using 3D elements is you can’t use the more basic technique of using 2D trackers to match the 3D element.  If you don’t know about 2D tracking you can view one of my latest blogs about it here https://22dayslater.com/2014/05/19/its-all-in-the-eyes-the-zombie-eyes/

Actually that’s not completely true.  If the camera isn’t moving around the object too much then you’d get away with this, which is something we did for out low budget one day horror that you can see here   Because the real footage was being seen from a pretty flat on view I knew that I could use a 2D track to basically “tack” the 3D animation to a point on the screen.

But for the shot of Matt, his head moves quite a bit and we see it from quite a few angles, so I knew the knife would be seen from many different angles as well.

This is where a different technique has to be used which is 3D tracking.  Like 2D tracking it uses points on the screen to work out how things are moving. But unlike 2D trackers it triangulates  using special algorithms to work out things like the Z depth of where things are in the scene. Although a lot of 3D trackers have automated settings, these usually only work on simple scenes. If a scene has a lot going on, with a lot of camera movement, it’s sometimes necessary to give the tracker more information, for example the focal length of the camera.  Sometimes you’ll see on the making of movies little markers, especially on green screen sets. These markers are a good way of showing the computer points to lock onto.  3D tracking is a real art in itself and something that can take many attempts to get a good result.

To track Matt’s head, I imported a 3D mesh that was similar to his head and scaled it to fit the real footage. The 3D tracker could use this as a way of marking where it needed to be in the footage.  You can see this in the video below.  Excuse the “Demo mode” I only have a demo version of the capture software

Now that I had the information I could map the real footage onto the 3D mesh and add a 3D knife. Below is an image of the 3D knife un-textured.

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It was then simply a case of animating the knife going into the 3D head.  I added lights that looked about right to where they would of been in the real set and also added shaders to the knife so it looked like its real life counterpart. Shaders are a way of telling the computer what material an object is made of, basically how it will react with light. So in this case it was a stainless steel knife so needed to be very reflective.

The last thing I needed to do was to add a trickle of blood that ran down Matt’s forehead. To do this I used some of the fake blood we’d made up for the scenes with Katie and the hat.  In case you’re interested, making fake blood is very easy and involves Syrup, red food dyes and coffee.I might do a blog on that at some point.

I shot various version of this fake blood pouring down a green screen as you can see below

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It was then a case of removing the green and cropping just one trickle of blood.  I used a 2D tracker so that it would stick to the movement of Matt. And as a final touch I used a tool in After Effects to bend it slightly so that it looked like it was following the contours of his face.

The last touch was to add a shadow to the area around the knife.

Here is a clip showing the different layers.

And here is the final result

The other knife shots were achieved in a similar way.  The only other thing worth mentioning is I added a slight blood burst when Kevin gets the knife yanked out of his head. This was a mixture of using stock footage and also a dust hit that I tinted red as I wanted to get that faint spray of blood you’d get if it was real.

So that’s that till next time.

 

Peter

 

 

 

 

 

Final few shots

Just a quick update to let everyone know that I’m just in the process of finishing off the final few VFX shots for the film.  If you remember around a month ago I demonstrated how we filled a hall with just five people using green screen techniques.

Well I’ve got to do the same but with some front facing crowd. The problem with this is that you can’t get away with duplicating the same people a number of times because you can see their faces. So unless you want a crowd that is full of quadruplets you have to shoot more people.

So right now we’re working on setting up a date to shoot a few more audience shots.

This film really does seem to be going on FOREVER!!.

I was going to show you lots of juicy computer graphic techniques but the problem is is that they all involve spoilers.

So instead I’m going to show you a monster I’ve been working on in the style of the great Ray Harryhausen. It has nothing to do with the film but I guess it’s still film related and makes up for the lack of pictures in this post.  There will be a small man about to get stomped in the image, I just haven’t got around to making him yet.

Maybe I’ll do a tutorial on creating CG monsters, if anyone is interested?

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The secrets of CG movies

I wrote this brief overview on computer graphics for a presentation I did last month.

Over the years I’ve found that there’s a lot of people that seem interested in how computer graphics and more precisly movies like Toy Story are made.

So I decided it might be of interest to some of  you as well.  It’s only a very rough overview and obviously there’s a hell of a lot more to the art of computer graphics but hopefully it will give you some idea of what goes into making these amazing movies.

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I created this image in 2005. The face was based off of my Grandad. 

CG stands for Computer graphics

After the script has been finalised just like with traditional movies,  a CG movie should start with a story board.
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Once a storyboard has been drawn, animated movies usually have what’s called an animatic or Pre-vis. This is basically a moving storyboard. It gives everyone a much better sense to what the final movie will be like.

This link below shows the rough version of the short animation I created Baggage. This started off as very basic blocked out animation (Animatic) As I completed the animation I’d replace the rough version shots with the completed animations.  In the video you’ll see that some of the animations are still very basic,  these are from the animatic.

You’ll also notice that none of the shots look very pretty, this is because they still need to through a process called rendering which I cover further down in this article.

Animatic

Once everyone is happy with how the story flows production can start.

Unlike live action films in CG you don’t get anything for free, everything has to be made from scratch.  From huge skyscrapers right down to plug sockets on a wall. If it needs to be in the film then it has to be made.

Although just like sets on movies, you can cheat and  make facades. Below is a link to another blog post I did a while back on the creation of the street scene also featured in my short Baggage.

Making a CG street

Most computer graphic models are made up of shapes called Polygons, These are basically flat squares. The more polygons you have the more detail you can have in your models.  But with more polygons the longer it takes the computer to process. It’s always wise to use real world reference to aid in the building of your models but you can also use photos as a basis to texture (colour) your model

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Once you have built your models you need to add colour and materials to make them look real.  These can be taken from photos or created using algorithms within the computer. The term for this process is called texturing and shading. Texturing refers to the colours while shading refers to how light will interact with the material.  Just like in the real world, where light bounces of materials in different ways, the same can be achieved in the computer.  For example think about the difference between a tennis ball and a pool ball.

Pool balls are shiny and reflective

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Where as tennis balls have no reflections and thus no shine either.

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In this following video I take a simple brick texture and apply it to a surface.  Using separate black and white images I can tell the computer how shiny the object it is as well as how bumpy it is.   These separate images are usually replicas of the original colour image but have various grey scale intensities that allow the computer to know how shiny or bumpy you want your surface to be.

NOTE: Please excuse the “Demo Mode” across the middle. I was using a capture software that I downloaded so they stick that across in till you decide to pay for it.

Texture shading demonstration

If the object being created is a character or something that needs to deform in an organic way, then it needs to have bones, very much like we do.  This allows the object to bend.

Where the bones are placed dictates how the object can bend.  And just like a puppet these characters need to have controls so that the puppeteer/animator can control the character.  This process is called rigging.

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Once the character has been rigged it can be given to the animator to animate.

There’s a common misconception with computer animation.  A lot of people I speak to believe that computer animation takes a lot less time than hand drawn animation.  The reality is that although the computer does make some things easier, there are others parts that take longer and so both methods take a similar amount of time.

In the link below I show a brief demonstration of how an animator would use the controls on the characters to put them into a pose. Again please excuse the big “Demo Mode” across the middle.

Posing a character

The animator will of been given a shot to animate. They sometimes get the animatic as a template to where the character needs to move to and how long it should take.  If there  are a number of characters in the one shot it’s usually the responsibility of the one animator to animate all of the characters.

Usually an animator will shoot live action reference of them acting out the actions that the character needs to do.  They may also sketch some thumbnails to get an idea of how to add appeal to the poses.

Reference

They then need to create all the main key poses that express the movements and feelings of the character.  Once they’ve done that they will add in all of the “in-betweens” which is the part of the action between the main poses. Below is link to a shot from the short Baggage where Sam pulls his bag from some Tube train doors.  This stage is called blocking which is where all the main poses of the animation have been put in place.

Key poses

It’s also worth noting how some of the poses I’ve stretched his body more then would usually happen. This is a principle of animation called Squash and Stretch. There are 12 key principles in animation which were thought up originally by the nine old men at Disney. You can find out more information about these principles here Principles

The next part of the process is to pass the animation onto the rendering and lighting team.  This is where the sets and characters are lit and finally a process of what is called rendering.
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Rendering is where the computer takes all of the information that has been created. So things like where the polygons sit in the virtual world, what moves where, how the lights affect the shading and textures, what’s solid what’s transparent, what’s reflective.  All this information is computed so that we the viewer get to see the final result.

And that is a brief overview of what goes into computer graphics.Like I mentioned at the start this is a very basic overview, if you’re interested in learning more then give me a shout I’m more than happy to talk about it or point you to some good websites.

In till next time!

Music, film and animation!

I thought I’d just give everyone an update to what’s going on at the moment.

So it may appear from the activity on the blog that there’s not much going on. It’s actually completely crazy so I thought I’d just give you an overview of what’s going on.

So, I’m still working on finishing The Great Spielron before Christmas although it might spill over as there’s just soooo much to do. 

Although we’ve finished shooting I’ve still got to add in a lot of CG effects, I’ve also got to do a lot of removals of things like lights that were in some of the shots. 

Most of the film is edited except for two scenes.

I’ve still got to fix all the sound and foley and sound effects and colour grade a lot of it. 

But that’s not all. I also decided to shoot a music video and do an fun animation for Christmas because for some stupid reason I thought I might be able to do it all…which so far isn’t going that way.

I thought I’d post up some stills from each of these to give you some idea of how they’re coming along. 

You can probably guess which ones which.

Short film clips from the horror the great Spielron

Snapshots from music video

animation for christmas with snowmen and baubles

 

So again apologies for the slow down in updates regarding the film.  I promise that everything will resume back to normal once Christmas is out the way.

Oh yeah I almost forgot that’s another little task I have to sort out, Christmas Shopping!