tredeger
07-02-2006, 12:49 AM
I just went through Charbel Koueik's RiggingPRO tutorial DVD for building a bipedal character rig in Softimage XSI and I thought some of you might find a thorough review useful.
Building a really good rig can be an extremely challenging undertaking and any high quality material on the subject is welcome indeed. There are lots of great and not so great resources out there if you're working in Maya or Max, but if you're using XSI and not already a rigging pro, you've probably hungered for something like this for a while. So is RiggingPRO worth your time?
Once you've purchased the "DVD" it is immediately available as a series of downloadable quicktime movies, scene files, and an executable file that serves as the interface to the movies. You must run the movies through the interface to view them (the interface is basically an anti-piracy device), but the quicktime features you need like easy timeline scrubbing remain intact. The interface can be a tad glitchy at times but this really doesn't get in the way of using the product.
Some people might prefer to receive a physical DVD for their $60 but the download system works really well. You can download the files immediately instead of waiting for the post. There is an email registration process required to activate your tutorial and they promise a 24 hour turn around. My delay was less than an hour. I found this to be a very convenient distribution system that I'm certain reduces the cost of the product and makes updates faster and easier. If you need a physical DVD, Charbel will make arrangements with you.
Intended audience:
Some people looking at this DVD will come to it wanting to learn all the technical magic behind advanced professional rigs with crazy features while others will be animators who want to do as little work as possible as painlessly as possible in order to get a rig that works for their fairly straightforward needs. Most people will fall somewhere inbetween. This tutorial was intended to be a training DVD that just happens build a specific finished and polished bi-pedal character rig. You should come away from the experience with a general understanding of techniques and concepts gained via the construction of a practical example. In other words, you should be able to not only build this rig as needed, but to take it's features and incorporate them into your own custom designs. Nevertheless, a lot of people should find the rig itself to be more than adequate for their personal needs and if that is the case, you'll be very well served by the comprehensive presentation of it's construction.
You'll get the most out of this DVD if you already have some experience with basic rigging in XSI but it isn't required to produce a result. I don't think you need to be an expert to take advantage of the lessons presented here but the more you try to get to the theory and logic behind the construction, the better able you'll be to extend the design.
The Rig:
This is a body rig only. No discussion of facial rigs is included. No discussion of eveloping the mesh once you've built the rig is given.
The rig itself is feature rich and it really doesn't matter if they aren't the features you personally want in a rig. It includes cartoon features like stretchy limbs and nice user interface elements like color coding the spine whenever it is outside it's base length. Auto-orient or "align" features are also included. I've recently worked with some rigs from a school that included these kinds of features but had implemented them very poorly. Charbel's implementations are rock solid and the difference is the difference between a joy to work with and unusable feature. The solid implementation owes both to a good clean design on Charbel's part and to the robust constraint blending of XSI, on which many of these features rely.
As impressive as any individual features of the rig is the way the design keeps the features from running over each other. They all work together well in any permutation and they don't clutter each other up.
The rig is set up as a set of IK bones, FK controls (nested nulls) and Skin Bones gluing them together. The skin bones are not actually chains, but poly cubes and serve both as a visual representation of the character and the objects to which you will envelop your mesh. Auxiliary chains are used to control twisting of skin bones at the limbs. For all of the different hierarchies in the rig, it is clearly organized and easy to understand as you move through it.
When it comes to feet, you want to be able to roll off the sides of the feet and pivot from the ankle, ball, heel and toe. These "standard" features are very well implemented in the conventional way here and all of the control is placed on sliders which reside on a single CON. Personally, I am extremely frustrated by this type of control but it is more or less the current state of the art. I dislike the approach because you have a ton of controls that basically control the orientation of the foot. Multiple controls are necessary because the foot can pivot from so many places. But in practice, animating with this kind of control (which is admittedly the current standard) requires way too much counter animation for a wide range of common actions. If you roll up on the ball of your foot to take a step, lift the foot off the ground, then want to pivot from the ankle, you have to simultaneously counter animate out the ball roll before the heel strikes the ground. Then you have to animate out the ankle rotation as you pivot on the heel during the foot plant.
Another example of a basic limitation of this sort of control is having a character "walk" his foot out toward his side in a heel-toe, heel-toe manner, alternating between those two pivot points. (Think of country western line dancing). In most systems, including the standard XSI rig foot, the pivot points "walk away" from the controls and the controls can end up facing each other when they should be aligned. I find this maddening.
A proper solution would have a single variable pivot so that you could just look at a single set of rotation values and always know exactly how the foot is oriented regardless of it's position in space or from which point it is currently pivoting. This is an extremely difficult problem to solve and rig without robust bi-directional control and I am not aware of anyone having a good system in widespread use. In the mean time, we are stuck with the standard foot. As far as standard feet go, Charbel's is very well implemented and very clearly presented. If you build it exactly as he demonstrates, you'll have a pretty good understanding of the logic behind a system that is commonly confusing to people. He opts to place all the controls on sliders on a single foot control and this makes for a nice contrast to the design of the multi control approach taken by the basic XSI rig. I do think Charbel's foot, once you have multiple sliders set at different values can get a little confusing to manipulate visually, especially with respect to pivoting from the ankle, but it's a problem common to just about all the feet out there now.
There are different styles of rig design and you should be aware of Charbel's approach. He likes to minimize the number of control objects on the character while placing a lot of the advanced controls on a menu of sliders accessible from a single control. To a large degree, this is a stylistic choice. Personally, I like to avoid slider controls as much as possible for things that control the character (like foot rolling) and use them only to control states of controls, like stretching and FK-IK blending. But you should come away from this tutorial with a sufficient understanding of the implementation to incorporate it into a rig that follows your own style.
Additionally, an old school approach is taken here with respect to controls. XSI's own Michael Isner has talked about the logic of the XSI design with respect to rigging being one that encourages direct manipulation of chain elements to avoid dependancy problems that arise with extra control objects. This is why XSI makes it easy to change the appearance of bones, roots and effectors. While Charbel makes liberal use of the changing appearances for clarity, his design reverts back to a conventional reliance on many control objects. This is especially the case with the FK control of limbs. This is NOT a bad thing, it's a consequence of his design and I'm not sure you could implement all the features of this rig in as straightforward a manner if you tried to adhere to the XSI new school approach. I do think all the extra finger bones he uses are entirely unnecessary. It is far more straightforward to change the primary appearance of the finger chains to boxes for visual reference and the shadow display to rings which can be seen around the fingers of the mesh for direct selection/manipulation during animation. My main point here is that an awareness and understanding of the different philosophies will serve you well as you develop your own rig.
Rig performance:
I'm finding that the rig performance is generally satisfactory but can tend to be a bit slow, especially when you are actually using it to drive even a moderately sized mesh. I believe this owes primarily to the expressions and driven keys that underlie much of the rigs functionality. Driven keys are used to set the foot roll values, the auto clavicle, and the spine color coding and this method can really affect rig performance. The other types of expressions represent less of a hit, but do exert some overhead costs that in some very real world situations could be quite noticable. I would like to see a discussion of various workarounds to these issues, perhaps ways of more directly wiring up parameters or of muting expressions/locking values of features when they aren't needed. For instance, in Maya, you can often replace an expression by wiring attributes through a math node and increase performance by orders of magnitude. I'm less well versed with the possibilities in XSI, but would very much appreciate some time devoted to such admittedly boring but important rig issues. For instance, I don't think your rig should calculate the stretch values of all your limbs when the stretch functions are turned off.
Presentation of Material:
This is where the DVD really shows it's strength. The presentation is absolutely comprehensive and if you copy exactly what is done on screen you will end up with the same result. (He walks through mirroring the leg, but you'll have to mirror the arm on your own. Otherwise, absolutely everything is show). At the same time, while it doesn't skip any steps, it is perfectly paced both for first time viewing, later general review, and simultaneously working through the example. As a quicktime, being able to scrub about a lesson visually makes working through very easy, though you definitely want to run dual monitors. As a nice touch you can choose a presentation format of either 1024 or 1280, a convenience that is easy to underappreciate. I actually also like the slightly less crisp than the app resolution of the screen as it helped distinguish my own XSI dialog boxes from Charbel's.
As repetitive as a lot of the steps are, Charbel goes through them quickly enough that they aren't painfullly tedious at any stage of viewing and having seen many tutorials where this is not the case i must say this is a real accomplishment. The overall presentation is extremely well scripted for real world use. this makes it possible to fairly easily duplicate his step and appreciate the logic of the design as it unfolds along the way.
As far as learning the logic and concepts goes, you definitely have to kind of figure out what he's doing as it goes. This is made easier by the fact that naming conventions are clear yet concise and the overall layout of the rig is well organized without any really unnecessary odds and ends. If you've ever tried to dissect a poorly made rig you know that it is easy to throw in a lot of extra nulls and bones that ultimately don't serve much purpose. For all it's features, the rig is very clean. When it's all said and done, the rigs inner workings should not be a mystery. That being said, very little preliminary discussion is ever given to a concept before it is actually implemented. Personally, I would have preferred a few more minutes of conceptual theory and some discussion of how to generalize a technique before actually diving into something. Other than an overview of the rig features at the very beginning this is basically absent. It isn't essential, but it would be nice. There is likewise no discussion of alternative approaches. It's a very specific approach to teaching some concepts you will ultimately want to generalize and innovate upon.
Overall, while I would favor a bit more of a scientific/theoretical/philosophical presentation at times, this specific case study has everything you really need and should serve it's intended audience quite well.
The order of lessons is superb and the large daunting task of building a whole rig is broken up into very digestable discrete chunks. You will be surprised how quickly you can actually work through the entire DVD while both building the rig and learning and processing what you're doing. Building the leg first, then the spine, then the arm and head is exactly the right sequence in order to learn the concepts in a way that won't be overwhelming. You should defintely go through the lessons in order the first time through. The arm wiring especially builds upon the logic of the leg wiring.
While I have mostly praise for the structure and presentation of the lessons, there are a few places where the quality is not up to par. There are times when you will find yourself building objects for things which you will "get back to later". This hurts in trying to understand the logic of the design. Of course, it is efficient to go ahead and build all your control nulls first if you already know the design, but for presenting and teaching the rig, it can be confusing. Thankfully, this isn't too egregious an offense and rarely committed. Most of the infractions occur with the lessons in the arms, after you are already fairly well versed with Charbel's approach and thinking. But there are some places where it would have been more logical to build a complete function rather than efficiently bouncing around several different features. On the whole, I'm pretty happy with what's there and the script is really tight for the extensive content that's here.
Scripting/Expressions:
The scripting and expressions required of advanced rigs is one of the most confusing and complicated aspects of the process. The step by every step approach taken in this DVD makes this part about as painless as possible. Once again, the clear naming conventions help compensate for any lack of theoretical discussion, as does the fact that he doesn't take any scripter's shortcuts in the presentation. By relying on XSI's nice drag and drop scripting features, Charbel does an excellent job of exposing the logic of how the functionality is wired up. The most complex expressions he employs are built up atomically and are clear at every step. This tutorial won't turn you into a hard core rig coder, but it will give you a very good sense of how much you can achive with a certain level of scripting proficiency and provides a taste of how far a fairly intermediate level of coding can really take you.
I'm not the biggest fan of driven keys (linked keys in XSI) but they are probably the best approach for animators looking for a little more control over their rigs. All the expressions you need for the functionality of the rig are thoroughly shown so I'd call this aspect of the presentation above average to very good.
Support:
Charbel was heavily promoting this DVD on the cgtalk forum just before it came out and I must admit I was quite skeptical. Since the DVD's release I have been both pleased with the content itself and the fact that he has remained quite active in providing support and answering customer questions in a timely fashion as they come up on the forum.
What's Missing:
I'm concluding this review with a note of what's missing not because I want this to end on a negative tone, but because I think these are all things that could be easily addressed and included in the distribution package of the DVD as an update. The distribution scheme makes this simple.
Support for 4.2 and 5.0. The scene files were all opened and saved in 5.1 which means even if you are running 5.0 you can't open them. Charbel argues that 5.1 fixes a bug that relates to expressions used in the files so you should really update (which is free). I updated (finally) today and am glad I did, but would like to see the files available just for the sake of completeness. Note that where Charbel occasionally accesses a parameter from the keyig panel, if you are on 4.2, just open a PPG of the object to get to these parameters (generally SRT values). While working through the videos as you build the rig in the app is about as smooth an experience as you could make, some supporting material in the form of printable written documentation would greatly ease the process. There are 3 html or PDF's a would love to see- 1. a generalized checklist of steps for each lesson (just naming the process that encapsulates a series of steps can go a long way to exposing the purpose and logic to a student), 2. a logical map or schematic of sorts, presented in parts of the structure and design of the rig. A general version and a specific version could be extremely useful in terms of being able to apply the various design elements to future rigs and innovate upon them, 3. A written list of all the expressions in a single file for study with comments as to their logic. This would have value both as a study aid and because scrubbing a video for specific code is a pain.
Conclusion:
Is this tutorial worth your time and money? It is worth your money in large part because it won't waste your time. If you are looking to improve your understanding for solid rig design you will be well served by this tutorial and if you are looking for instruction that is both XSI specific and really takes advantage of this applications special qualities, look no further. I can both recommend this DVD and report that I am looking forward to seeing what Charbel comes up with next.
Building a really good rig can be an extremely challenging undertaking and any high quality material on the subject is welcome indeed. There are lots of great and not so great resources out there if you're working in Maya or Max, but if you're using XSI and not already a rigging pro, you've probably hungered for something like this for a while. So is RiggingPRO worth your time?
Once you've purchased the "DVD" it is immediately available as a series of downloadable quicktime movies, scene files, and an executable file that serves as the interface to the movies. You must run the movies through the interface to view them (the interface is basically an anti-piracy device), but the quicktime features you need like easy timeline scrubbing remain intact. The interface can be a tad glitchy at times but this really doesn't get in the way of using the product.
Some people might prefer to receive a physical DVD for their $60 but the download system works really well. You can download the files immediately instead of waiting for the post. There is an email registration process required to activate your tutorial and they promise a 24 hour turn around. My delay was less than an hour. I found this to be a very convenient distribution system that I'm certain reduces the cost of the product and makes updates faster and easier. If you need a physical DVD, Charbel will make arrangements with you.
Intended audience:
Some people looking at this DVD will come to it wanting to learn all the technical magic behind advanced professional rigs with crazy features while others will be animators who want to do as little work as possible as painlessly as possible in order to get a rig that works for their fairly straightforward needs. Most people will fall somewhere inbetween. This tutorial was intended to be a training DVD that just happens build a specific finished and polished bi-pedal character rig. You should come away from the experience with a general understanding of techniques and concepts gained via the construction of a practical example. In other words, you should be able to not only build this rig as needed, but to take it's features and incorporate them into your own custom designs. Nevertheless, a lot of people should find the rig itself to be more than adequate for their personal needs and if that is the case, you'll be very well served by the comprehensive presentation of it's construction.
You'll get the most out of this DVD if you already have some experience with basic rigging in XSI but it isn't required to produce a result. I don't think you need to be an expert to take advantage of the lessons presented here but the more you try to get to the theory and logic behind the construction, the better able you'll be to extend the design.
The Rig:
This is a body rig only. No discussion of facial rigs is included. No discussion of eveloping the mesh once you've built the rig is given.
The rig itself is feature rich and it really doesn't matter if they aren't the features you personally want in a rig. It includes cartoon features like stretchy limbs and nice user interface elements like color coding the spine whenever it is outside it's base length. Auto-orient or "align" features are also included. I've recently worked with some rigs from a school that included these kinds of features but had implemented them very poorly. Charbel's implementations are rock solid and the difference is the difference between a joy to work with and unusable feature. The solid implementation owes both to a good clean design on Charbel's part and to the robust constraint blending of XSI, on which many of these features rely.
As impressive as any individual features of the rig is the way the design keeps the features from running over each other. They all work together well in any permutation and they don't clutter each other up.
The rig is set up as a set of IK bones, FK controls (nested nulls) and Skin Bones gluing them together. The skin bones are not actually chains, but poly cubes and serve both as a visual representation of the character and the objects to which you will envelop your mesh. Auxiliary chains are used to control twisting of skin bones at the limbs. For all of the different hierarchies in the rig, it is clearly organized and easy to understand as you move through it.
When it comes to feet, you want to be able to roll off the sides of the feet and pivot from the ankle, ball, heel and toe. These "standard" features are very well implemented in the conventional way here and all of the control is placed on sliders which reside on a single CON. Personally, I am extremely frustrated by this type of control but it is more or less the current state of the art. I dislike the approach because you have a ton of controls that basically control the orientation of the foot. Multiple controls are necessary because the foot can pivot from so many places. But in practice, animating with this kind of control (which is admittedly the current standard) requires way too much counter animation for a wide range of common actions. If you roll up on the ball of your foot to take a step, lift the foot off the ground, then want to pivot from the ankle, you have to simultaneously counter animate out the ball roll before the heel strikes the ground. Then you have to animate out the ankle rotation as you pivot on the heel during the foot plant.
Another example of a basic limitation of this sort of control is having a character "walk" his foot out toward his side in a heel-toe, heel-toe manner, alternating between those two pivot points. (Think of country western line dancing). In most systems, including the standard XSI rig foot, the pivot points "walk away" from the controls and the controls can end up facing each other when they should be aligned. I find this maddening.
A proper solution would have a single variable pivot so that you could just look at a single set of rotation values and always know exactly how the foot is oriented regardless of it's position in space or from which point it is currently pivoting. This is an extremely difficult problem to solve and rig without robust bi-directional control and I am not aware of anyone having a good system in widespread use. In the mean time, we are stuck with the standard foot. As far as standard feet go, Charbel's is very well implemented and very clearly presented. If you build it exactly as he demonstrates, you'll have a pretty good understanding of the logic behind a system that is commonly confusing to people. He opts to place all the controls on sliders on a single foot control and this makes for a nice contrast to the design of the multi control approach taken by the basic XSI rig. I do think Charbel's foot, once you have multiple sliders set at different values can get a little confusing to manipulate visually, especially with respect to pivoting from the ankle, but it's a problem common to just about all the feet out there now.
There are different styles of rig design and you should be aware of Charbel's approach. He likes to minimize the number of control objects on the character while placing a lot of the advanced controls on a menu of sliders accessible from a single control. To a large degree, this is a stylistic choice. Personally, I like to avoid slider controls as much as possible for things that control the character (like foot rolling) and use them only to control states of controls, like stretching and FK-IK blending. But you should come away from this tutorial with a sufficient understanding of the implementation to incorporate it into a rig that follows your own style.
Additionally, an old school approach is taken here with respect to controls. XSI's own Michael Isner has talked about the logic of the XSI design with respect to rigging being one that encourages direct manipulation of chain elements to avoid dependancy problems that arise with extra control objects. This is why XSI makes it easy to change the appearance of bones, roots and effectors. While Charbel makes liberal use of the changing appearances for clarity, his design reverts back to a conventional reliance on many control objects. This is especially the case with the FK control of limbs. This is NOT a bad thing, it's a consequence of his design and I'm not sure you could implement all the features of this rig in as straightforward a manner if you tried to adhere to the XSI new school approach. I do think all the extra finger bones he uses are entirely unnecessary. It is far more straightforward to change the primary appearance of the finger chains to boxes for visual reference and the shadow display to rings which can be seen around the fingers of the mesh for direct selection/manipulation during animation. My main point here is that an awareness and understanding of the different philosophies will serve you well as you develop your own rig.
Rig performance:
I'm finding that the rig performance is generally satisfactory but can tend to be a bit slow, especially when you are actually using it to drive even a moderately sized mesh. I believe this owes primarily to the expressions and driven keys that underlie much of the rigs functionality. Driven keys are used to set the foot roll values, the auto clavicle, and the spine color coding and this method can really affect rig performance. The other types of expressions represent less of a hit, but do exert some overhead costs that in some very real world situations could be quite noticable. I would like to see a discussion of various workarounds to these issues, perhaps ways of more directly wiring up parameters or of muting expressions/locking values of features when they aren't needed. For instance, in Maya, you can often replace an expression by wiring attributes through a math node and increase performance by orders of magnitude. I'm less well versed with the possibilities in XSI, but would very much appreciate some time devoted to such admittedly boring but important rig issues. For instance, I don't think your rig should calculate the stretch values of all your limbs when the stretch functions are turned off.
Presentation of Material:
This is where the DVD really shows it's strength. The presentation is absolutely comprehensive and if you copy exactly what is done on screen you will end up with the same result. (He walks through mirroring the leg, but you'll have to mirror the arm on your own. Otherwise, absolutely everything is show). At the same time, while it doesn't skip any steps, it is perfectly paced both for first time viewing, later general review, and simultaneously working through the example. As a quicktime, being able to scrub about a lesson visually makes working through very easy, though you definitely want to run dual monitors. As a nice touch you can choose a presentation format of either 1024 or 1280, a convenience that is easy to underappreciate. I actually also like the slightly less crisp than the app resolution of the screen as it helped distinguish my own XSI dialog boxes from Charbel's.
As repetitive as a lot of the steps are, Charbel goes through them quickly enough that they aren't painfullly tedious at any stage of viewing and having seen many tutorials where this is not the case i must say this is a real accomplishment. The overall presentation is extremely well scripted for real world use. this makes it possible to fairly easily duplicate his step and appreciate the logic of the design as it unfolds along the way.
As far as learning the logic and concepts goes, you definitely have to kind of figure out what he's doing as it goes. This is made easier by the fact that naming conventions are clear yet concise and the overall layout of the rig is well organized without any really unnecessary odds and ends. If you've ever tried to dissect a poorly made rig you know that it is easy to throw in a lot of extra nulls and bones that ultimately don't serve much purpose. For all it's features, the rig is very clean. When it's all said and done, the rigs inner workings should not be a mystery. That being said, very little preliminary discussion is ever given to a concept before it is actually implemented. Personally, I would have preferred a few more minutes of conceptual theory and some discussion of how to generalize a technique before actually diving into something. Other than an overview of the rig features at the very beginning this is basically absent. It isn't essential, but it would be nice. There is likewise no discussion of alternative approaches. It's a very specific approach to teaching some concepts you will ultimately want to generalize and innovate upon.
Overall, while I would favor a bit more of a scientific/theoretical/philosophical presentation at times, this specific case study has everything you really need and should serve it's intended audience quite well.
The order of lessons is superb and the large daunting task of building a whole rig is broken up into very digestable discrete chunks. You will be surprised how quickly you can actually work through the entire DVD while both building the rig and learning and processing what you're doing. Building the leg first, then the spine, then the arm and head is exactly the right sequence in order to learn the concepts in a way that won't be overwhelming. You should defintely go through the lessons in order the first time through. The arm wiring especially builds upon the logic of the leg wiring.
While I have mostly praise for the structure and presentation of the lessons, there are a few places where the quality is not up to par. There are times when you will find yourself building objects for things which you will "get back to later". This hurts in trying to understand the logic of the design. Of course, it is efficient to go ahead and build all your control nulls first if you already know the design, but for presenting and teaching the rig, it can be confusing. Thankfully, this isn't too egregious an offense and rarely committed. Most of the infractions occur with the lessons in the arms, after you are already fairly well versed with Charbel's approach and thinking. But there are some places where it would have been more logical to build a complete function rather than efficiently bouncing around several different features. On the whole, I'm pretty happy with what's there and the script is really tight for the extensive content that's here.
Scripting/Expressions:
The scripting and expressions required of advanced rigs is one of the most confusing and complicated aspects of the process. The step by every step approach taken in this DVD makes this part about as painless as possible. Once again, the clear naming conventions help compensate for any lack of theoretical discussion, as does the fact that he doesn't take any scripter's shortcuts in the presentation. By relying on XSI's nice drag and drop scripting features, Charbel does an excellent job of exposing the logic of how the functionality is wired up. The most complex expressions he employs are built up atomically and are clear at every step. This tutorial won't turn you into a hard core rig coder, but it will give you a very good sense of how much you can achive with a certain level of scripting proficiency and provides a taste of how far a fairly intermediate level of coding can really take you.
I'm not the biggest fan of driven keys (linked keys in XSI) but they are probably the best approach for animators looking for a little more control over their rigs. All the expressions you need for the functionality of the rig are thoroughly shown so I'd call this aspect of the presentation above average to very good.
Support:
Charbel was heavily promoting this DVD on the cgtalk forum just before it came out and I must admit I was quite skeptical. Since the DVD's release I have been both pleased with the content itself and the fact that he has remained quite active in providing support and answering customer questions in a timely fashion as they come up on the forum.
What's Missing:
I'm concluding this review with a note of what's missing not because I want this to end on a negative tone, but because I think these are all things that could be easily addressed and included in the distribution package of the DVD as an update. The distribution scheme makes this simple.
Support for 4.2 and 5.0. The scene files were all opened and saved in 5.1 which means even if you are running 5.0 you can't open them. Charbel argues that 5.1 fixes a bug that relates to expressions used in the files so you should really update (which is free). I updated (finally) today and am glad I did, but would like to see the files available just for the sake of completeness. Note that where Charbel occasionally accesses a parameter from the keyig panel, if you are on 4.2, just open a PPG of the object to get to these parameters (generally SRT values). While working through the videos as you build the rig in the app is about as smooth an experience as you could make, some supporting material in the form of printable written documentation would greatly ease the process. There are 3 html or PDF's a would love to see- 1. a generalized checklist of steps for each lesson (just naming the process that encapsulates a series of steps can go a long way to exposing the purpose and logic to a student), 2. a logical map or schematic of sorts, presented in parts of the structure and design of the rig. A general version and a specific version could be extremely useful in terms of being able to apply the various design elements to future rigs and innovate upon them, 3. A written list of all the expressions in a single file for study with comments as to their logic. This would have value both as a study aid and because scrubbing a video for specific code is a pain.
Conclusion:
Is this tutorial worth your time and money? It is worth your money in large part because it won't waste your time. If you are looking to improve your understanding for solid rig design you will be well served by this tutorial and if you are looking for instruction that is both XSI specific and really takes advantage of this applications special qualities, look no further. I can both recommend this DVD and report that I am looking forward to seeing what Charbel comes up with next.