03 June 2012

Sebastian König - Blender 2.5 - 3D Compositing - Streaming Online Video Tutorial

I tend to be a big fan of ebooks and pdfs rather than videos, as I usually find that videos don't tend to get into enough detail. When I heard that Sebastian König was going to come out with another Blender tutorial, and that it would be on Compositing in Blender 2.5, I knew I would be watching that video!

Product Specifications:
  • Name: Blender 3D Compositing
  • Author: Sebastian König
  • Price: $49.95 (Oct 23 2010)
  • Type: Streaming Video Format (Not Downloadable)
  • Length: 5 Hours (Roughly)
Unsurprisingly Sebastian's newest tutorial video is about Blender 2.5's Compositing system. This is interesting to me for 2 reasons, first it's a tutorial from Sebastian, and this means that even if I am not particularly interested in the topic he is teaching (see previous review of Vray with Blender), you know that it will be well produced and well taught. The the other reason is that it's a tutorial about Blender 2.5's Compositing system. Taking these 2 facts together and knowing that Tutorials on using Blender Compositing system are few and far between, while ones that specially teach you about 2.5's system are almost as rare as unicorns. The second this tutorial was available to purchase, I did so.

For those that do not know, Blenders Compositing system allows you to make alterations to scenes and pictures, without having to rerender things using Blender's rendering engine or any other external engine. The Blender's Compsitor is integrated with Blender so has the advantage of having extra information to draw upon when carrying out compositing tasks, as well as generally being much faster than having to rerender a scene. It is also true that a lot of effects that can be achieved easily within the compositor, would be extraordinarily difficult using just Blender rendering system.

If given the above, Blenders Compositor sounds like it would be very useful, then you no doubt want to start using it to get all the benefits it has to offer in your own work? It's at this point one of Blenders biggest short comings crops up, lack of documentation! Trying to get to grips with some of the features of Blenders Compositor can be a hair pulling experience. If you have ever seen some Blender Compositing videos on the likes of youtube/vimeo, they often end up being just a video telling you to connect things in certain ways and poof you get out a particular effect, very little time is given over to explaining why and how particular node setups work.

Sebastian's tutorial is not at all like this, he not only takes that time to cover how to connect the nodes in special ways to achieve different things, but also goes into a good amount of detail as to why you connect things the way he does.

Sebastians's video starts off covering the basics of how to use the compositor, by using a simple scene as an example. This first section will help people who have never used Blender's Compositor before in getting up to speed. The coverage of using Mask Layers, Vector Blur, ID Masks and Defocusing Nodes will come in very useful for all Blender Compositor users, as questions on how to use these Node come up frequently.

Once the simpler topics have been covered, the video moves on to covering Scene and Render Layers and how to use them to color correct certain parts of an image. I found this section of the video very clear and easy to understand. I especially liked the coverage of Mask Layers, as you don't often see them described and I think it will be new to a lot of beginning and even experienced Blender users. Another thing of note was how Sebastian highlighted how nodes can interact with each other and sometimes give results that you don't expect and how you can get around some of the problems and bugs that are in the Blender Compositor.

After going over Scene Layers and Render Layers, Sebastian moves on to describing in some detail what Pre-multiplication is and how you can use it to prevent compositing artifacts (such as having a strange outlines around composited parts of a scene). This issue causes a lot of problems with people starting out using the compositor, so having it covered as a topic on its own is very useful. You only have to look at the number of posts on BlenderArtists.org to realize how many people are completely vexed by Pre-multiplication and the issues it can cause.

Coverage of how to use both Raytraced and Approximate Ambient Occlusion passes in helping to improve the overall lighting with in the compositor are very informative, as is the information on how Approximate Ambient Occlusion can be improved by using the Subsurface Modifier to improve its results by balancing the face sizes of a scenes geometry. I didn't know about this so I was very pleased to see it included in this video.

One of the most difficult subjects for beginning compositors to get to grips with is the topic of Pixelmath. Pixelmath is a fundamental subject when using any compositor/image editing software. Sebastian takes a good deal of time to describe how it works and how it affects the various blending modes when using the Mix Nodes in the compositor. I found it clear and easy to understand so I think other people will to. Especially useful were the links directing to wikipedia, which give in-depth coverage of how the different Mix modes work as far as their Pixelmath formulas go. It greatly helps in understanding a lot of what is done later on in the rest of the video, so is worth watching until you get it.

One section of the video I really liked and found very interesting was the break down of how the composite passes can be split apart and combined back together to get almost the original scene back and how to use this to alter many aspects of how a scene looks. This may sound unimportant but often one of the questions asked is how do particular render passes combine and Sebastian takes time to explain how, this is very hard to come by information. He also shows how to get around some bugs with the shadow pass (which has since been fixed in Blender SVN) and the refraction pass bug (not yet fixed).

To fix the bugs Sebastian uses the Object ID Pass Index and as a result goes into a large amount of detail as to how to use ID Masks and Object Index Passes, a very useful feature and will make your compositing tasks within Blender much easier.

One amazing section of the video is the information on how to relight a scene using the Blenders Compositor, Render Layers and Lightgroups (similar to how LuxRender does with real time adjustable render lights). The technique is demonstrated using a bunkers scene. The transformation to fully lighting scene is very impressive to watch, Blender users with a interest in Lighting will love this section.

This concludes the first major part of the compositing tutorial, from here on in, the topics change to show how to composite models into live actions footage using data obtained from a previous SynthEyes tutorial. You do not need to have seen the SynthEyes tutorial or have SynthEyes to follow along though.

A nuclear accident scene is modeled and the compositor is used to add various special effects to the scene, various masking techniques are covered so as to use a Camera Tracked scene in the compositor.

After all this the final scene is color corrected and graded using the compositor and briefly it is shown how to make a short movie from the scene.

I can honestly say I don't have any criticisms of the Sebastian's tutorial itself, but with cmivfx.com the hoster. Their video delivery system, when I was watching it often disconnected and there was no easy way to restart it, also I found that the flash video version of the tutorial had a bit missing at the end. I hope for the flash version of the video this has either been fixed or will be fixed. Luckily the html5 compatible version of the video was complete, although unfortunately that is still in beta and not yet compatible with Firefox (though they promise it will be). Another issue with the html5 player was that there was no full screen option (well there was it just did not seem to work). Videos from cmivfx just don't tend to be a crisp as those on blendercookie, though I am not sure why. The disconnect and buffering issues would be helped greatly if they allowed you to fully buffer up videos before watching them, like you can with blendercookie.com.

So in conclusion, Sebastian has done an excellent job with this Blender Compositing tutorial, it is currently the best tutorial out there on Blender 2.5's Compositor, well worth the price, just a shame cmivfx lets him down.

If you are or want to be a Blender Compositor and you want a video to show you how, this is it, go out and buy it!

Review Score 90%