Sebastian König - Blender Green Screen Keying Concepts - Tutorial Video Review

Whenever Sebastian König comes out with another Blender video tutorial, I know that I will have the next few hours of my day planned out for me. So when I found out the that Mr König had put out a Keying/Green Screening tutorial off I went to purchase the video.

Product Specifications:

• Name: Blender GreenScreen Keying Concepts
• Author: Sebastian König
• Price: $19.95 (29 Jan 2011)
• Type: Streamable Tutorial Video
• Length: 1 Hour 48 Min Roughly

First thing to note is that this tutorial video covers how to use Blender Compositing Node system to produce Mattes/Keys from a green/blue/red screens, using various techniques. A feature which is vital if you want to extract live action footage from a scene and composite different elements together.

Chapter Sections:

• Chapter 1 - Getting Started (Video Position 00:00:00)
• Chapter 2 - The Channel Key (Video Position 00:13:40)
• Chapter 3 - Your Own Custom Key Key (Video Position 00:24:18)
• Chapter 4 - Lightwrap (Video Position 00:32:54)
• Chapter 5 - Garbage Mattes (Video Position 00:47:17)
• Chapter 6 - Channel Blur (Video Position 01:01:01)
• Chapter 7 - Rotoscoping (Video Position 01:11:42)
• Chapter 8 - Compositing (Video Position 01:26:05)

This video is the second in the series of CMIVFX tutorials covering the topics of how to use Blender to carryout various studio level production tasks using Blender's Compositing system. The previous tutorial (Blender 3D Compositing also produced by Mr König is related to this video and it would be useful to have seen that previous video because some of the topics covered are easier to understand having seen the previous video. But if you are not totally new to Blender or Blenders Node editor you should be able to follow along without any difficulty even if you haven't seen the earlier tutorial.

The production quality of the video tutorials is very high and encoded very clearly so there should be no problems viewing the streaming video from their website. I had been busy and had to be away from the web for a while so I downloaded the video and watched it from within VLC, again it was very clear and easy to watch.

Chapter 1 - Covers the initial setup of Blender and its interface, going over how to get various still and movie sequences into Blender Compositing system so as to allow you to do the various Keying processes. Throughout the tutorial various 2k and 4k files are used (studio quality). For those that do not know the theory of how GreenScreens work Mr König describes briefly the theory of how they work. After the theory a few ways that could be used to make Mattes/Keys are described and Mr König explains how they work and explains how they are not useful for the needs of this tutorial.

Chapter 2 - Having covered some of the bad ways to pull a Matte from images in Chapter 1, Chapter 2 covers better methods using Blender Channel Key Node. Covering how to pull Mattes from both still and moving images with and without the effects of motion blur upon the images. After all, it's all very well to pull a Matte from a still none motion blurred image, but when the images are moving, dealing with the problems motion blur introduces is very important and it is explain and handled very well by Sebastian. Sebastian shows both how to use the nodes to manually pull a Matte using Nodes, as well as Nodes that do it automatically. Often tutorials just mention the automatic ways to pull Mattes rather than explaining how it all works, the flexibility that is afforded in understanding exactly how things work makes you much more likely to be able to pull more difficult Mattes in future. The methods used throughout all the chapters remind me a lot of a book "Steve Wright - Digital Compositing For Film And Video" another excellent source of digital compositing information, which is much easier to follow when in video form as this tutorial is.

Chapter 3 - Covers making a custom made Matte puller using Blender Node system, useful when over methods that Blender provides do not automatically work as required. This section is fairly involved but was clear and easy to follow.

Chapter 4 - After having pulled at Matte from the previous chapter, Lightwrapping are explained and then a demonstration of how to create them are gone over. After lightwrapping is covered, a simple method of making Vignettes are demonstrated. This time however the shots that are being processing are more difficult as it has a drummer drumming which has large amount of motion Blur and simpler Matte pulling methods are not sufficient.

Chapter 5 - Covers the uses of Garbage Mattes and how to combine multiple Garbage Mattes to achieve a clean Matte pull on different parts of a short, as different parts of the short required different methods to get clean results. Excellent demonstration of how to use Blenders mask like features to achieve the result needed.

Chapter 6 - Channel Blur is a slightly advanced chapter because it covers how to take lower quality GreenScreen shots which are pixelated/lower resolution, and uses various YCbCr colorspace tricks to fake a higher resolution Matte. How the trick works is very well explained although it would have helped to have had more information on exactly how the YCbCr color system works, though enough information was given to be able to carry out the color channel blurring trick, and if your really want to know all the detailed specific of YcbCr Colorspace you can always do a google search. This is a very useful technique, makes me wish Blender had an inbuilt automatic node for doing this trick as standard. A really useful website (www.hollywoodcamerawork.us) is mentioned that hosts many different GreenScreen stills and movies. The images used in this chapter have a woman with a transparent veil dancing around, and as a result it's a much harder task to pull a clean Matte, but Sebastian demonstrates how to do it efficiently with multiple Garbage Mattes and Masks from within Blender.

Chapter 7 - Rotoscoping, follows on from the previous chapter. Because the woman is dancing, an animated Garbage Matte is created using Blender RotoBezier feature, using this method Sebastian demonstrates the usefulness of Rotoscoping and Blender RotoBezier feature.

Chapter 8 - Compositing, this final chapter composites the Keyed images that were obtained from the previous chapters, using Blenders Compositor. Using the Images as Planes addon method of positioning extracted GreenScreened footage into Blender 3D Viewport is explained. Another useful trick described is recoloring of extracted GreenScreen material.

Each chapter is very well explained and there are numerous examples of how to use the various techniques described throughout all the chapters. Sebastian paces his descriptions of that various tasks in each of the chapters very well.

This tutorial stands well on its own or with the previous Compositing tutorial that Sebastian did. It in my opinion is well worth the money and very informative and full of useful tricks and tips. It will almost certainly have something useful in it for someone looking to improve their GreenScreen/Matte pulling skills.

Review Score 86%

Sebastian Koenig - Blender Shading and Fur - Mammoth - Streaming Video

It's been busy for me lately so I had not been able to review much in the way of Blender tutorials and also there was not a lot left to review. So I was pleased to find out about a new video training tutorial release from Sebastian Koenig, this time on the topics of Shading and Fur application to his Mammoth model series created in his previous 3 tutorial videos.

This is the 4th video tutorial released by Sebastian and follows on from the previous tutorials listed below:

• Blender Organic Modeling Techniques
• Unwrapping and Baking
• Texturing

While you don't have to have seen the previous tutorials to understand the ones that come after it, it certainly helps, though Sebastian does explain most of the information you need to know at the beginning of each tutorial and goes over in brief some of the additions from earlier videos.

So with that in mind what can be said about the newest addition, here the product overview:

• Product Specifications: Blender Shading and Fur
• Price : $19.95 (on 12th of Oct 2009)
• Video Run Length : Roughly 1 Hour 35 Minutes
• Format : Streaming Video

Since fur is often skipped over in training materials for Blender because of its fiddly nature and the fact that it can bring machines to their knees, it is good to see that Sebastian did not shy away from this sometimes difficult area to teach.

The tutorial starts by going over the initial material, lighting and scene setups that are used. This helps if you either haven't seen the previous videos or your memory is a bit foggy (mine was). Some may argue that this information was not needed and could have been time better used to explain fur topics, but others would argue the exact opposite.

I found the information on clip start and end shadow buffer values very informative and even learned a few quicker ways to set clip start and end values (I didn't know you could use the W key in the viewport to set the values).

A little more information on what a shadow buffered is and why altering the clip start and end values is a good thing to do could have helped for those that are not clear on what shadow buffers are, but this is not a beginners tutorial so it's to be expected. I also found it helpful that Sebastian explained that fur shadows do not work as expected with ray tracing and have to use shadow buffers, another useful bit of information to store away until needed.

After going over the shadow buffers the topic moves on to setting up the lighting in the scene, so as to get a well lighted model to show off the fur and shading better. Ambient occlusion usage is also covered and a few of the options that can be set for it are explained briefly.

The tutorial then moves on to a quick overview of the basic materials used on the mammoth model. A lot of this information was covered in previous tutorials but it still serves as a useful refresher (at least for me).

For the tusks on the mammoth Sebastian uses subsurface scattering and explains the SSS settings which again I found useful, especially what the Scale value stands for in relation to SSS.

At 22 minutes into the tutorial the primary topic of the tutorial is reached, that being adding fur to the mammoth. It may be frustrating to some having to wait a whole 22 minutes before you ever actually see any fur but the preceding information will probably make things easier for a lot of people.

Sebastian covers most of the major parameter controls for controlling how hair is generated and affected. He almost from the very beginning quickly explains how to use Parent and Child Strands to improve the appearance and performance of strand modeling, and later on in the video even covers the strand simplification controls, which I think is the first time I have seen that explained in a video tutorial, so to me that is excellent.

After covering the strand control parameters Sebastian goes on to explaining weight painting and vertex groups and how they are used to control how and where Strands are generated. The techniques described are used in the video to prevent fur from being emitted from the bottom of the feet and various places on the head of the mammoth, as well as to control the length and density of fur on parts of the mammoth, and use extensively in the rest of the tutorial.

On the weight painting section I liked the use of the Blur weight painting mode to make gradual transitions in weight painting boundaries.

At this point (35 mins) a test render is done with the current strand settings and Sebastian details how to speed up the render using the Strand Rendering option.

Once the render is completed Sebastian moves onto describing the Particle Mode and demonstrates how to alter the positions of strands using the various Particle Mode tools such as Comb and Add etc. He uses this mode to improve the position of the Strands in the render to make it look more fur like. A good demonstration of Point Select mode is given and Sebastian shows how to use the Strand Step value to make the strands more controllable.

At this point the video moves on to altering the materials and texture settings of the generated fur strands, things definitely take a more advanced turn at this point.

Most of the major parameters are explained, but in some places I found it a little difficult to keep up with some of the material and texture settings.

I would have found it useful to have had more information as to how and why the various material settings were used, especially in relation to how to use the Stencil mask type. As this Stencil mask type is referenced a lot and the description of why it was used was not very clear to me. It did seem to me that at some points it became a mass of button clicks with some things not really being explain clearly enough. I maybe need to go back and re-watch those bits. Other than that everything else was well explained.

The use of the color blend texture with fur was explained very well, though I think it should have been spelled out that it is used to make hair transparent at the end, to make it fade out and have a feathered and not sharp end. Though again this is not a beginners tutorial, so chances are we are assumed to know this.

Multiple Strand/Particle Systems are used and layered together and Sebastian takes some time to explain how they combine together to produce the final fur output.

A nice feature of the tutorial is that Sebastian takes the time to explain how to make various types of Strands such as ponytail strands and braids, very handy. Also covered were using various clumping settings to make the mammoth fur look matted and clumped. If nothing else the information on the Kink and Branch settings will be worth knowing as it is very, very useful.

So all in all this is another excellent video tutorial from Sebastian, as mentioned above the only thing I found confusing was the use of Mask/Stencil textures to add variation to hair colors, but that is likely to be my fault not Sebastian's.

Review Score 85%

Sebastian Koenig - Blender Organic Modeling - Mammoth - Streaming Video Review

cmiVFX.com is a training site for the graphical and visual effects, covering many systems and platforms.

cmiVFX delivers most of its content in the form of streaming video which can be purchased and watched online. The system requires the use of flash player for the videos to be viewable.

I was debating with myself as to weather I should review this site or not for a number of reasons. The first being that the streaming videos are only available for viewing online (as far as I can tell). Which means that you constantly have to be connected to the internet with a good broadband connection to see the videos that you purchased.

Obviously this is fine so long as you are connected and do have a fast connection. Unfortunately I don't have a particularly great connection speed so therefore would have benefited greatly from a downloadable version of the purchased video so I could watch offline. The second reason is partially related to the first in that the streaming technology they use seems not to allow hitting the pause button when I first starting a video stream so as to allow my connection to buffer more of the video before it starts to play to prevent skipping and buffering. This really annoys me as it is completely inconsiderate. After all I paid for the content I should really be able to press pause and have more of the video download to my machine before I start the video again. Third would be the fact that I really think the video formats should always be in open formats such as ogg and not be tied to having to use some sort of flash based system.

From the above it should be clear why I was mostly against reviewing these videos. However, this was all before Sebastian Koenig decided he wanted to put some tutorials of his on the cmiVFX.com site. I mean really this is Sebastian, he does things with Blender that reach the levels of massively awesome (do a search on google for Sebastian Koenig Fly to see what I mean).

Sebastian's tutorial covers the stages involved in creating a realistic model of a mammoth, all starting from a cube.

• Product Specifications:
• Price : $49.95 (on 5th of Aug 2009)
• Video Run Length : Roughly 5 hours
• Format : Streaming Video

The first thing I noted (just before purchasing it) was the price. At $49.95 it is a fairly expensive video tutorial. Yes it is 5 hours but still it does seem rather expensive to me. Even more so given the other complaints mentioned above.

Issues with price aside, the video tutorials quality is very good in both terms of content and viewing quality (almost no fuzziness or pixellation artifacts). It is not a beginners tutorial though, you are really expected to know your way around Blender and be a reasonably good modeler. This is not surprising as the range of topics covered within the tutorial is quiet broad.

Very helpfully Sebastian clearly describes what he is doing throughout the video and I had no problems understanding what he was saying with his accent (German I think) but then I am English. So if you have a problem with accents this could be something to keep in mind. Unfortunately there are no on screen key press displays in the video, though Sebastian almost always describes what all the keys are that he is using.

The video covers all the stages involved in creating and modelling the mammoth from setting up a background image, using the grease pencil, box modelling, poly to poly modelling, subsurfacing, weight painting, using array modifiers, sculpting and such things. Extensive use of proportional editing is also gone through and even though this is not a beginners tutorial Sebastian does spend some time going through some of the basics for those advanced modellers coming from other modelling environments.

So all in all the videos are excellent and the informational content is extremely good (not surprising given what Sebastian can do). And just on the content of what he teaches I would have to rate the video very highly.

However the system that Sebastian is hosting his videos upon just makes me uncomfortable. If you are ok with a completely locked in system where you can't download the videos you legitimately purchased and can be sure to be connected to the net all the time and have an always quick connection, then you will be ok. The videos that are streamed are very clear and the interface is reasonably clear and doesn't take up too much screen space.

Taking into account the issues I have, I think it only fair to give 2 review scores one on just Sebastians tutorial and another review score of cmiVFX.com video delivery system.

I can only hope that Sebastian finds a better system for delivering his videos as they are excellent, or that cmiVFX comes up with a better more user friendly video delivery system.

Sebastian Review 90% (tutorial awesome information packed)
cmiVFX Review 50% (delivery system stinks)