Tasybear,
I’d completely agree with you. Not enough effort is given to modeling issues when preparing a character for animation. Too often people will build a model expecting it to deform perfectly but more than not, they’re left using the ole “sledgehammer” to knock vertices back into place with a weight map. I like the idea of exploring other avenues of geometry manipulation in EIAS like cage editing and SmartSkins. They could be very beneficial when Tesla arrives. However, we do need an “old school” weight mapping system that works and is intuitive.
I’m gonna wipe the slate clean again because the Igors feel this thread has gotten too overwhelmed with high concepts and ideas. I also feel we may be arguing symmantics. So why don’t we just start with the basics?
What is a weight map?
Well by my definition, a weight map is a grayscale map that defines the areas of influence of a bone to the vertices of geometry “skinned” to that bone. As the bone moves, it deforms or alters the positions of those vertices dependent on the amount of influence or “weight” that is being exerted on the skin. White areas on a weight map represent attraction influence to the bone where black areas do not. A range of grays provide a level of percentage of influence a bone has on the position of the vertices.
How is a weight map created?
Depending on what application you’re using determines if the answer to this question gets tricky. Initially, a weight map is generated through an application’s skinning or binding tools. I like to use the term binding “globals” because they determine the “conditions” of the bind at the immediate point of skinning. Sometimes I’ll also call this the “initial” bind. Typically, after the initial bind is complete, most applications will convert the intitial bind state into a series of weight maps which correspond to each individual influence found within the skeletal hierarchy. One bone = 1 weight map.
Does this process happen with EI?
No. It does not. EI will not convert the intitial bind into a visable, editable state of 1 bone to 1 weight map. Instead, EI chooses to retain the bind in an “active” state and “fine tunes” the bind through an EI strength map.
How does EI’s binding globals work?
EI’s binding globals include: Weight Min, Falloff Powers, and Bone Max. These 3 settings alter the bind across the entire skeleton. Additional refinements can be made on a “local” level by altering special deformer values in the bone “Special” tab. These tools will alter the initial bind on a per bone basis. Within the solution of the intitial bind, all the vertices are averaged across the hierarchy’s bones based on the Bone Max setting. A bone max setting of 5 means that five bones will be used to average the position of a vertice during a deformation in relationship of the vertice’s distance from these bones. Closer bones derive more influence where more distant bones exert less influence. While this process is identical to the processes being used in other applications, EI will not convert the bind into a visable 1 bone to 1 map solution.
So what does EI do instead?
EI implements a Strength Map, which is essentially an exclusion map. The Strength Map tells EI where to remove or reduce influence away from the bone so the geometry deforms less. This is the exact same process being used in other applications, but the difference is EI elects to show the user the area being painted for exclusion rather than showing the user the combined exclusion map and the intitial bind together. The result is the EI user must think in terms of excluding influence or negative space, where most other applications show the weight influence in positive space. This exclusion methodology can become confusing to the user the more and more bones that are introduced into solution’s hierarchy. To accomplish a “positive” strength painting methodology in EI, the user must create a strength map for every bone in the hierarchy and remove all influence of the initial bind by filling the Strength Map with black. He must then paint back in areas where he wishes to reassert influence. This is time consuming and impractical.
Are strength maps and weight maps the same thing?
Again, this is a matter of symmantics. Technicallly, one could say that strength maps and weight maps are the same thing IF one does not consider the initial bind a form of weight map itself. For some, the initial bind is simply a constant calculation of the binding globals while a weight map is the device used to redistribute the weighting values within the solution. Personally I always think of a weight map as being the COMBINED data of both the initial bind and the exclusion map TOGETHER, not SEPARATELY. Strength maps by themselves are meaningless without being combined with the intitial bind.
So which method should we use?
I believe most users who do any kind of skinning prefer seeing the binding solution as a series of grayscale images that combine the exclusion map that is painted by the user along with the intitial bind to form a “positive” representation of the weight map for every bone/influence in the hierarchy.
Should we get rid of EI Strength maps?
No. Because EI Strength Maps still allow the user to define areas on geometry for use with various plugins. But for skinning purposes, an option to see the combined solution rather than just the exclusion map is needed for the best workflow.
What about your other ideas about weight pruning, spreadsheets, and “bypassing” the bind state?
Means to manually alter the bind state through these tools are still important to obtain, but not until we make a decision to support the 1 bone to 1 combined weight map methodology. EI should also consider the binding process as a tool that is executed rather than a state that must be constantly “on”. If users want to change binding globals they can do so, but not without being asked first.