texturing tutorials

http://www.3dmd.net/MAYA_texturing_tutorials.htm

just a quick link Phil found for texturing/uv mapping tutorials

Texturing/Blendshapes: before or after skinning?

Having spoken to Alex Hulse, I have a clearer idea of what order I should really be doing things in. Both texturing and blendshapes should be done before skinning. With blendshaping the head, it's important that the head doesn't deform due to weight influences. I did a quick test and sure enough that's the way to do it. Here it is.

Thanks Alex!

Set Driven Keys

Heres a link to a good tutorial website.
http://www.learning-maya.com/24-0-character-setup-tutorials.html

It's there where I found this tutorial into set driven keys for hands.
http://www.final3.com/html/tutorials/drivenKeys.htm

This tutorial was definately useful, as it explains different attribute types that led to my revelation in the last blog. It also pointed out for me that I can in fact key more than one driven object at once, meaning that I can have just one attribute on a hand controller controlling the whole finger movement. This may not sound any different to what I had done before, but there is a big difference. Previously I had set driven keys in a chain reaction effect. I.e I keyed one joint to be effected by an attribute, which in turn drove another joint, which in turn drove the last. This meant that if I were to individually move any of the joints in the chain it would inevitably drive the others. The way the tutorial suggests however, means that none of the joints actually drive anything; only the attribute does. This means the animator would be actually be able to move individual finger joints without causing the rest of them to curl up.

The only downside to this however, is that I can't create any new attributes attatched to the same rotation used by the driven joints as Maya won't let me. Meaning I can no longer have attributes in the channel box for every bone. You can still adjust them manually, but it's not as animator freindly.

Either way, this is still progression. However, I will look into it further to see if there's a way around this. And I know there is. The tutorial talks about using a 'seperator' which it promises can help solve this issue. Theres a lot of MEL bogging down this tutorial though, so I will have to look at this tomorrow when I'm not knackered.

High-rez / Low-rez switch: im such an idiot

I worked it out. Im so stupid it was so obvious and under my nose the whole time. The switch between hi-rez and low-rez on Moom had nothing to do with any of this complicated control-rig / bound rig stuff from Hyper-Realistic Creature Creation. No, I've been barking up the wrong tree. In fact it wasn't a tree at all it was a lamp post. Thats how far off I was!!

The solutions very, very simple. All I ever had to do was create a new attribute and set the data type to booleans. This creates an attribute that has only two values; on and off. All I then had to do was use the connections editor to link the attribute to the divisions level found in the polysmoothface input for the all models geometery. Again, I'm very glad I worked this out now before I carried on with the mammoth task of trying to figure out all that MEL scripting.

You may need to click on the images to enlarge to see what I'm talking about. I used Lil' G from our last project as an example of how this will work for this one. A simple attribute attatched to a controller is a nice and easy way to make it more accessible for the animator.

Thanx to Moom for the inspiration, but I actually worked this out while breezing through a tutorial on using set driven keys for a hand setup. I will post the link for this in the relevant post.

Control rig / Bound rig

After having a read through the advanced rigging section in Hyper-Realistic Creature Creation, it seems as though creating a low-rez control rig set to drive the high-rez bound rig is going to involve a serious amount of work relating to complex MEL scripts. I'm not sure if I have time to figure all this out, so while I'm holding this in mind for something I'd ultimately like to be able to do I'm lowering the priority of doing it for this project. I want to do something really good, and to that end simpler is usually better. Plus, the reason this technique is often used in industry standard rigs is simply that industry standard models often have a very high poly-count. (Particularly with hyper-realistic models, which is what this book is about.) Therefore this technique is perhaps innapropriate for the nice simple cartoon models that we have in mind for our project.

However, in trying to find a simpler way to do the low-rez to high-rez switch, I came across a golden nugget of wisdom in Mastering Maya 7. Refer to the problem mentioned in this link to a rig from last terms project:

http://gringoarts.blogspot.com/2008/11/bouncy.html

In particular the bit that says,
"Basically what I still need to do is sort out the orientation of the wrist joints, as at the moment they do not correspond to the rotation of the hand controllers. You can still rotate the hands, but its not very user freindly. "
Well I never did get that problem solved, as sorting out the local rotation axis of an individual joint is very fiddly, and even then it's very difficult to get it to be exactly where it should. However, the technique explained in Mastering Maya 7 will prevent this problem from occuring. The technique is to use EP curves to blueprint where the skeleton will go before actually building it, with the edit points being where the joints should go. This means when building the skeleton you can simply snap the joints straight to where they should be, saving the process of re-adjusting the positioning afterwards. (This is relevant, as it is at this stage where normally the joint orientations are knocked out of line.)

Handy.

Refer to the image for a visual example of what I mean. The two joints on the left have just been placed. As you can see their orientation is in the correct position (x pointing towards the child joint). The joint on the right however has been moved. When you move a joint the orientation remains where it was when it was placed. This is why it is out of line.

(You might have noticed that on the post for the old blog I was going to attempt the low-rez/high-rez switch then as well. In case you were wondering, that particular tutorial had no information on it at all, which is why it never happened.)

Moom

I thought I'd include moom here as part of my research, mainly because I respect this model and rig immensly. I'd also say it's a more relevant example of how I should be modelling than the examples in Stop Staring as it's a far more simple cartoon style. The fundamentals are still all here though; A widely diverse facial control panel, and a face modelled with circular topology surrounding the areas that deform the most. While this is the rough model, Moom has a control that enables the user to switch between a low rez and high rez model, which as I have previously mentioned, I want to do for my own. The head is disconnected from the body, which is important for doing blendshapes, otherwise I will end up with loads of entire models hidden in the scene.

Set Driven Keys

Here's a quick test of how set driven keys could potentially be useful in rigging. Watch this playblast and understand that the whole movement came from one attribute in the channel box.
(Ignore the crappy hand model, it was only a quick botch-job for the sake of a demo.)

While this has a lot of potential, unfortunately it means the animator can no longer have individual control over any of the joints in that finger without driving the movement of the next in the chain. This hopefully illustrates the importance of finding a way around this.

Reading Material

I figured I may as well post a link to the books I am using in case this blog inspires anyone to find them for themselves. I would reccomend them.

Stop Staring:
http://www.amazon.co.uk/Stop-Staring-Facial-Modeling-Animation/dp/0471789208/ref=sr_1_1?ie=UTF8&s=books&qid=1232302336&sr=1-1

Hyper-Realistic Creature Creation:
http://www.amazon.co.uk/Maya-Techniques-Hyper-real-Creature-Texturing/dp/1897177046/ref=pd_sim_b_2

Mastering Maya 7
http://www.amazon.co.uk/s/ref=nb_ss_b?url=search-alias%3Dstripbooks&field-keywords=mastering+maya+7

Blendshapes and modelling

Heres a fantastic quote from Stop Staring (second edition) page 103 in reference to blendshapes:

"The face is always expressing somehow. The point is this: The model you're starting with isn't your character. These shapes you're about to build are. Treat every shape like it's the only shape anyone will ever see because combinations of the shapes you build here really are all anyone will ever see."

Just thought that was inspirational and true.


Heres a quick list of the sections from the book that I will be using to help make sure I do this right:

Page 76-89- facial modelling.
(Teeth and tongue are covered after this extract, but im not sure if the models going to need to be this complicated or not. Will discuss it with Phil tomorrow.) This extract uses the polygon toolset, but if I am using a different surface material it can be easilly translated into the toolset for that. If I go with Phils idea of subdivision surfaces then it's the same toolset anyway.

Chapter 6.
Very useful section with practical advice on the best way to create the fundamental blendshapes used in a diverse mouth setup, including information on avoiding common pitfalls. (Primarily the dangers of additive shapes.) This section also shows the importance of a properly modelled face, and goes on to explain blendshape weights.

Chapter 7.
Practical tutorial on modelling and rigging the eyes/brows. (Looking at Phils designs the eyes are going to be far simpler than the setup from the book, but I will still need to go through this for the eyebrow setup.)

Chapter 12
A far more detailed explanation of making an industry standard control panel as the facial interface.


The only nugget of info Stop Staring doesn't include is when to actually do the blendshapes. I.e. before or after skinning the body rig, as I still don't know whether it's even important or not. I havn't been able to find an answer anywhere, so I'm presuming it doesn't matter, but I don't want to assume anything. I have emailed Alex Hulse this question, so I should get my answer before I have to start doing it.


By the way Phil, as soon as I finish finding out what I need to know from this book, I will lend it to you. Theres a really good section on facial animation and acting that I think you ought to read.

Basic facial control

Following a very basic tutorial from Stop Staring (second edition) by Jason Osipa, I have learnt how to do facial controls that are reflective of an industry standard setup. By this I mean a setup that uses objects in the actual scene to control the blendshapes, rather than using the blendshape window. This is highly beneficial for the animator, as it is far more user friendly. Check out this quick playblast, you'll see what I mean.

This tutorial has also given me insight into the possibilities of this teqnique. It makes use of the limitations found in the attribute editor, as well as creating and linking expressions to multiple blendshapes. I expect this can also be achieved through channel control and the connections editor, but knowing about expressions has led me to wonder whether or not this can be used to solve my concerns about using set driven keys. Also using the limitations from the attribute editor is particularly useful as you can set it so that you can move an object one way along an axis, but not the other. It's also in this editor where if you do allow it to move the other way, then when linking this to the blendshape it's essentially telling Maya to do the opposite of whatever the blendshape does. This means I only need to create one shape for the wide pose and when moving the slider the other way it will work out the narrow by itself.

It's also important to note here that this particular tutorial from Stop Staring has already removed a preconception of mine about the way the mouth opens and closes. Previously I had assumed that it would just open universally, but of course it does not. Only the lower jaw moves. Obvious now that I think about it, but still I am glad I realised now rather than later.

Needless to say this is going to be extremely useful, as I can use this same technique to create diverse controls for the eyes, brows, and a more expressive mouth.

Research

Modelling reserach:
I will need to look primarily into facial modelling, and how curves can be used as an easy control device for blendshapes. I also need to determine wether it would be worth using nurbs to account for the low poly-count limit while keeping the surfaces looking smooth, and wether the use of nurbs would effect the painting weights or uv mapping.

Rigging research:
I need to find out if theres a way of using set driven keys, i.e. for fingers, without losing control over the individual joints. I would also like to investigate the possiblities of building a basic low-rez control rig for animation that is convertable to a high-rez polished rig for rendering.

Texturing research:
I need to find examples of claymation, as the brief states they would like to see designs based around traditional claymation. This should help me decide on how to texture effectively to the needs of the comission.


This should all be done by Monday.