Hello all!
Time for another project! Im aiming to make a completely rigged human character from start to finish. My plan is to work on everything from topology, rigging, look into blend shapes/corrective blend shapes and then hopefully develop him as a character and use him for pretty much anything i like. I suppose he would be like my own morpheus or any of those other kind of awesome rigged characters you can download.
Here is my base so far. This is a few hours a day for the last 3 days trying to work on topology and all round silhouette. Could probably get rid of that damn triangle on the hand and up the polycount seeing he is only at 5144 Tris, but trying to waste as little polys as possible to try and get a clean result.
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He may still need some work but this is where i got up to over the last 2 days.
Wireframe:
Unselected model:
Polycount so far:
The purpose of this exercise is to put good use to blend shapes/ corrective blend shapes, so i guess perfect topology isn't crucial for the corrective BS......but a good base is a good start!
I worked on the lips a fair bit too as it seemed his lips pretty much didnt exist. I filled in the face around the jaw area with some more topology and left it that, i then took an existing rig from a previous character and bound it to the mesh. Now ill go over and do some quick skinning, as the point of this project is blend shapes and corrective blend shapes.
Im hoping i have created enough supporting edge loops around the eyes, lips, nose, mouth and brows to create some pretty decent blend shapes, and i hope i've left enough in the shoulders, elbows and knees to make decent corrective blend shapes. if not its back to the drawing board!
Here's a pic of the current topology as well as the rig im using:
With the elbows i tried to achieve the look i wanted with only one blend shape, but found it difficult to do it all in the one go and at such a large rotation on the elbow joint.
Then, when it came to the shoulders i knew i was going to have a hard time trying to get perfect deformation from a T pose to straight up. I achieved my result using 4 blend shapes and activating them at certain angles via set driven keys. This produced a decent result and allowed me to get an almost seamless blend when rotating up on the shoulder joint.
My character has now reached mexican wave status....
Admittedly, i was a little freaked out when i started moving verts and my blend shape stages looked like this:
I had no idea that the corrective blend shape would react so differently, i just assumed that you created your desired result and it formed it. I should have known that nothing in the 3d world is that simple (Facepalm). Next will be the knees and then on to facial expressions!!
Worked on the knees when brought up to hip level and created a nicer bend on the knee cap and the back of the leg. Also, helped the crotch and stomach of the character keep a little more shape as it bends down.
Ive found that although corrective blend shapes can give you more precise and vert by vert control on areas, it is also really time consuming and can be very tedious, with vert movements reacting differently from the base mesh to the corrective mesh. On that note though the i am really happy with the results so far for a first attempt at them. Thinking this technique could come in handy when it comes to show reel stuff and getting your characters moving and animating nicely.
Not being a master rigger, i'm sure all this is achievable with bones and weight painting, but i wouldn't even know where to start!
This thread hasn't been very tech heavy, so i'm going to post my options and the steps i took to get to where i am at the moment.
In the "Create Blend Shape Options":
I have left In-Between off. This option is all dependent on the order you have connected your blend shapes, in turn, which will effect the way that they react when they are activated. If ticked, blending occurs in a series, un-ticked, blending occurs parallel which allows multiple blend shapes to be activated at once, and not do crazy things like double translate verts and give you messy blends.
This is probably the lazy mans setting, but it has given me the result of all my blends working together.
Check topology: Specifies whether to check if the base shape and the target shape have the same topology. Blend shapes are all dependent on vert order and having the exact same mesh, this just guarantees that your connecting an exact copy as a blend shape.
In my list of input operations, you can see that i only have one input. I have kept all my blend shapes in one list and named them Body_Corrections, not only will this give you a cleaner list in your Channel Box, it will also help your shapes blend better. I found that if you create separate blends for the shoulders, knees, elbows etc, and you don't have them placed in the correct input order, you would get bad results and blends cancelling each other out.
Blend shapes are read from bottom to top, so, setting your deformation order as Front of Chain, will ensure that your blend will be placed underneath the skin cluster and the rig. (Which is a good thing)
Here is my window setup for my 2nd screen for creating my blend shapes:
My blend shape slider across the top displays all my blends (so far). Here you have the slider which turn your blends on and off. This also shows you how much value is being activated when moving my limbs eg. 0.8 of blend 1, 0.5 of blend 2, 0.2 of blend 3. Another use is the select button at the bottom of that window, that is the easiest way ive found to select your blend shapes to load it in to your Set Driven Key window as your DRIVEN.
You could probably select it in your hyper-shade by mapping your body mesh...but the hierarchy by this stage would be pretty confusing.
I have an extra camera set up to look around the mesh that is being corrected, and have my blend shape mesh up on my primary screen. Any edits update real time, so this makes it a lot easier to see your edits without having to move one primary camera every time.
Lastly, you've got the Add Blend Shape Target window and the outliner. These 2 windows go hand in hand and allow me to quickly select my meshes, hide and un-hide them and add them as a bland shape.
Creating the blend shape at the start is the first step, but if you are keeping them all under the one Blend node like i am, then all you have to do is add blends after that and watch your meshes pile up!
My process in ZBrush was to create a layer (for each expression), move the face around with the Move Topological brush (Being a low res mesh, it didn't lag like it does with a level 5 sub division mesh), and the transpose tools to move large areas, like opening the mouth. Once i was happy with my the shape, i would hit the GoZ button in the tool menu and it would export my active layer/s directly into maya, then it was a matter of repeating my steps of adding a blend shape to the same node.
Also, in the ZPlugin menu at the top of your screen, there
is a Maya Blend Shapes Plugin which goes through your layers exports them all in one go!
Once i had them all connected up, i found that when trying to activate multiple shapes at the one time, they would blend but would not deform nicely. Thats where the Paint Blend Shape Weights Tool comes in handy!
Edit Deformers> Paint Blend Shape Weights Tool
This tool works exactly like the Paint Weights tool for skinning joints. A list of your Blend Shapes will come up in yout tool settings, once clicked it will show you the influence of you Blend Shape on your mesh, white being 1 and black being 0.
Places like the eyebrows bunching up in the centre crease, and dimples double deforming were the areas that caused the most problems.
When it came time to mirroring these blends over to the other side, the pain of realizing im probably going to have to do this to the other side hit me....But that's when i worked some things out:
I thought about it a little more and downloaded this awesome mel script that does it for you called abSymMesh. (Download here: http://www.supercrumbly.com/3d.php?sid=112#.ULH5AYd3bF9)
This script does all the awesome stuff like scanning your original mesh and only mirroring altered vertices and flips your altered verts across your desired axis. I found that it wasn't 100% on its flips though and would leave one very noticeable stray vert sticking out so be wary of that.
The other option would be just to mirror every blend shape that you do on your mesh and then duplicate that mesh, and use the Paint Blend Shape Weights Tool to block out the side you don't want to activate.
In total now i have 23 corrective blend shapes for the left side of the body, and 26 blend shapes for the face. I am leaving the right side of the body as default at the moment so that i can demonstrate the benefits of them in class.