Thursday, November 18, 2010

How to merge animations?

There are two basic problems with copying animations from one figure to another:
  1. The skeletons do not match. First, the body proportions are off, especially if converting between male/female or realistic/stylized characters. And secondly, the non-obvious bones are often arranged completely differently. By obvious bones I mean the ones like armbones, shins and so on, that connect two visible joints. Non-obvious bones are hidden and their joints are not immediately visible - like backbone or shoulders. Thus the exact number and placement of such bones may vary, depending on how realistic and fluid motion is needed and how it is achieved.
  2. The bone orientations do not match. Even for bones that are perfectly aligned, like arms, the local coordinate systems can be very different and thus the transformations from one skeleton cannot be immediately carried over to another.
 How to deal with it?

In Khayyam I am currently doing the following procedure:
  1. Create one-to-one links between the well-defined bones of each skeleton - i.e. legs, shins, arms, forearms and heads. These function as anchors for matching body movements via IK solver.
  2. Pick rootmost joints of matched bones, i.e. hips and shoulders as anchor point pairs.
  3. Find the bone chain leading to last common ancestor of such pairs (starting from the point where previous chain ended). I.e. we get chains like these:
    3.1. Center_of_Mass -> Skeleton_Root -> Pelvis
    3.2. Lower_Backbone -> Upper_Backbone -> Chest
  4. Adjust chains, starting from rootmost, as closely as possible to anchor points using IK solver.
  5. Point all well-defined bones to the same direction as the originals, using IK solver

As you can see, it basically works, although some constraints on joint movement would be nice.

A demo video showing how dancing moves for DAZ skeleton can be imported to Esk Anderson figure


  1. Before you begin, be sure that you have learned the essay question twice. Then you come to know what you want to do. Mark the most essential concepts or phrases in the topic to help you stay focused on solving the question. Professors use specific keywords in essay topics to say what they ask you to do. For instance, an essay topic that demands you to “describe” a case will be separate from an essay topic that asks you to “argue” a situation. Be sure that you know the keyword in each essay topic you read. Explain: Insert the benefit and damage, powers and faults, etc. Balance: Explain the relationships and differences within two or more points. Don't ignore to tell why the comparison is helpful. Difference: Discuss how two or more things are unique or separate between those. Don't forget to tell why the difference is beneficial. Define: State what something involves, effects, scores, etc. Note List features or habits of the concept. You may also need to review something, such as an essay subject that asks "explain the main issues that directed to the Western Revolution." Talk: This is more logical. You usually start by explaining something and then give debates for or against it. You may want to explain the benefits or disadvantages of your point. Judge: Give the pros and cons, plus and minus for a case. You may be required to decide a comment for relevant support or decide evidence for weaknesses. Explain: Tell how or why that happened, or support your view on that. Fix: Usually held for more clear or real essays. You may be asked to include proof and study to create a case for a special position or set of data. Abstract: Usually, this involves to list the main ideas or issues of a topic. It could also ask you to give the main plans in order to then fully explain them. Most essay topics will not ask for clear summary without anything else.
    Refer: custom essay writing service

  2. Hello, I would like to thank you for sharing this interesting information. I appreciate reading it. The material you have provided here will be useful for ma lot of people. I was actually looking for a place where someone can help me to find movie critique writing service nevertheless, thanks.