Blend Shapes are driving me CRAZY!

[gmask]

Without going into too much detail I can suggest this...

You can blendshape sets.. what this means is that you do not have to involve the entire mesh in the calculation. This should not only improve the performance of your rig but also eliminate the other issues you are having.


You creat sets of selected CV's and as longas their numbering and topology are the same blendshapes work great and do not require you to have numerous copies of a one large model when you are mainly making adjustments to isolated areas.

[Akkalis]

Okay, first thing about creating blendshapes, and if you already know this, I appologize. First of all, select -ALL- your blendshapes, and then the target object. This creates them all under one node, do this if you want them to affect each other. Now, as for the second part, about your blendshape node appearing above the skincluster. This is easy enough to fix, open up your blendshape option box, go to advanced, and make sure where it says default or whatever, there is a drop down box near the center, and one of its options is 'INFRONT OF CHAIN" make sure this is turned on.

Also, why are you using blendshapes on the shoulders? to get proper deformations? I'd recommend influence objects for things like that, maybe not as good or as clean as blends, but I believe they are much faster to evaluate.

One more note about blendshapes, since you claim to know nothing, they are fairly simple, but they can be troublesome if something is wrong. Try and affect the same Vertices each time for better affects, and also, you can't mirror or negative scale a blendshape. For example, you can't -1 scale a L_BLINK for to get a R_BLINK with what is built in maya, it gives you weird mirrors when using the blendshape. There is however, a script call ShapeTools I believe, that lets you do just that. I've used it, its works, I don't know how it really works, but it does.

Goodlouck.

Also, what is MSc?

[quyeno]

thanks for your help guys, i've sorted it out now.

[mental]

heya gmask, about using sets of UVs/CVs with blendshapes:

in the past, i've found that it's impossible to add multiple blendshapes under one node/folder while using sets. when attempted Maya will give you an error saying something along the lines of "cannot find base object, last set chosen is not a base".

the only way i found around this was to create a new node/folder for every single blendshape and set their deformation order to parallel. it makes a mess of your inputs but it works :shrug:

i've encountered this behaviour since v4.0 (same in 4.5, haven't tried it in 5.0 yet) but i can't figure out a proper fix.

any suggestions?

thank you
-mental :surprised

[gmask]

Originally posted by mental
heya gmask, about using sets of UVs/CVs with blendshapes:

in the past, i've found that it's impossible to add multiple blendshapes under one node/folder while using sets. when attempted Maya will give you an error saying something along the lines of "cannot find base object, last set chosen is not a base".


I just tried it in 5 and I got no errors and it performed exactly as would be expected if you were just using shapes.

I made a set for each target object and the base object and then selected set memebers in the set editor in the correct order. Then chose the make blendshape.

[mental]

heya gmask!

i was able to try it out on a copy of Maya 5.0 and i got the same result: // Error: 'base' not a DAG item. //.... 'base' being the name of the base object in the blend.

i figure i'm doing something wrong since no one else is having trouble :shrug:

here's my setup:

i have 4 polygon cubes as the target and a fifth as the base. i've created sets composed of the same vertices for each cube. for the first blend i select cube1 and cube2 + the base and create an inbetween blend (whose deformation order i set to both default and parallel in different tests). so far so good the blend between the sets works.

but when i go to add a blendshape (be it a single target or inbetween) i always get the error: // Error: 'xxxx' not a DAG item. //. again 'xxxx' being the last object selected, the base. this only happens when i try to add a blendshape to an existing folder/node.

:argh:

-mental

[gmask]

Originally posted by mental
but when i go to add a blendshape (be it a single target or inbetween) i always get the error: // Error: 'xxxx' not a DAG item. //. again 'xxxx' being the last object selected, the base. this only happens when i try to add a blendshape to an existing folder/node.


You need to use the specify node option in add blendshape and select the blendnode that you are trying to add to then select the sets in the correct order and it should work fine.. it did for me ;-)

[mental]

thank you gmask but i've been using the 'specify node' option all along.

if it's not too much to ask could you take a look a this test scene that i've attached:

it includes 4 blend targets and their sets
- Cube_A
- Cube_B
- Cube_C
- Cube_D

plus a base shape (Base) and its set which already has one blend applied inbetween Cube_A and Cube_B. the problem arises when i try to add an inbetween blend to the blendnode called 'Morph' using Cube_C_Set, Cube_D_Set and the BaseSet

[gmask]

Originally posted by mental
plus a base shape (Base) and its set which already has one blend applied inbetween Cube_A and Cube_B. the problem arises when i try to add an inbetween blend to the blendnode called 'Morph' using Cube_C_Set, Cube_D_Set and the BaseSet

The problem is that your base set is a set of objects rather than vertices.. all the sets have to be selected vertices for this method to work.

You make each set (including the base set) by selecting the same vertices of each object.

[mental]

crud, i'm really sorry gmask but i attached a scene with the incorrect setup:

this new scene that i've attached has the setup that you just described (and it is the same setup that i've been using, all objects including the target shapes and the base have sets composed of the same vertices). that last scene i put together was a mistake on my part.

sorry for the confusion. and thank you once again for helping me out.

/edit: this might be a clue as to what's going wrong:
http://mywebpage.netscape.com/SoulJack3r/nodetype.jpg

the node type of the vertices in the BaseSet change after the first blend is applied. could this contribute to the error that i'm getting: // Error: 'BaseSet' not a DAG item. //

-mental

[gmask]

Originally posted by mental
plus a base shape (Base) and its set which already has one blend applied inbetween Cube_A and Cube_B. the problem arises when i try to add an inbetween blend to the blendnode called 'Morph' using Cube_C_Set, Cube_D_Set and the BaseSet

Okay I think I understand the problem..

I think you can only add one new blendshape at a time to a sequential blend.

You specify your "morph" noe and then you have to pick an index which is which slider tdo you want to add this shape to and since there is only 1 you enter 1. You then have to pick weight and since the weights for this kind of blend have to be unique you will get an error if you have two target sets selected. The determines where in the sequence the new target set appears. If it's .25 then it's near the bottom or 1 it is at the top.

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