![]() ![]() Equality constraints (red) seal together the loose boundaries between the leg and the body. ![]() The layering constraints force the leg’s silhouette to stay in front of the body (green), and the body’s silhouette to stay behind the leg (yellow). In steps (d) through (h) above, ARAP-L transforms a model from one with intersecting 3D parts to one with the depth ordering specified by the user. These constraints are applied only at the silhouettes of overlapping parts, and are dynamically updated each frame. The framework incorporates a set of layering and equality constraints, which move body parts along the z axis to prevent them from visibly intersecting each other. What’s novel about our layered “ARAP-L” approach is that it combines deformation and other constraints into a single optimization framework, allowing these processes to run in parallel at interactive speed, so that the user can manipulate the model in real time. Monster Mash’s layered deformation system, based on the well-known smooth deformation method as-rigid-as-possible (ARAP), solves both of these problems at once. Steps in creating a 2D sketch of an elephant.Īt this point we just have a static model - we need to give the user an easy way to pose the model, and also separate the intersecting parts somehow. The result is an ordered list of 2D regions. The user can also specify that some new parts should go behind the existing ones by drawing them with the right mouse button (c), and mark other parts as symmetrical by double-clicking on them (d). Drawing those additional strokes as open curves provides a hint to the system that they are meant to be smoothly connected with the regions they overlap. Then the user adds strokes to depict other body parts such as legs (b). The first step is to draw the body as a closed stroke (a). ![]() The result is a simple and intuitive user interface for sketching 3D figures.įor example, suppose the user wants to create a 3D model of an elephant. This abstraction makes the complex task of 3D modeling much easier: the user creates 2D regions by drawing their outlines, then the algorithm creates a 3D model by stitching the regions together and inflating them. The insight that makes this casual sketching approach possible is that many 3D models, particularly those of organic forms, can be described by an ordered set of overlapping 2D regions. There is also an online demo, where you can try it out for yourself. With Monster Mash, the user sketches out a character, and the software automatically converts it to a soft, deformable 3D model that the user can immediately animate by grabbing parts of it and moving them around in real time. In this post, we describe Monster Mash, an open source tool presented at SIGGRAPH Asia 2020 that allows experts and amateurs alike to create rich, expressive, deformable 3D models from scratch - and to animate them - all in a casual mode, without ever having to leave the 2D plane. This turns out to be essential to the creative process - when each sketch is nearly effortless, it is possible to iteratively explore the space of possibilities far more effectively. What these casual modes have in common is that they allow an artist to express a complete thought quickly and intuitively without fear of making a mistake. ![]() To explore this concept, we start with the observation that most forms of artistic expression have a casual mode: a classical guitarist might jam without any written music, a trained actor could ad-lib a line or two while rehearsing, and an oil painter can jot down a quick gesture drawing. With the recent development of tools that facilitate game character creation and game balance, a natural question arises: is it possible to democratize the 3D animation process so it’s accessible to everyone? Because of its complexity, 3D animation is generally practiced by teams of skilled specialists and is inaccessible to almost everyone else, despite decades of advances in technology and tools. Posted by Cassidy Curtis, Visual Designer and David Salesin, Principal Scientist, Google ResearchģD computer animation is a time-consuming and highly technical medium - to complete even a single animated scene requires numerous steps, like modeling, rigging and animating, each of which is itself a sub-discipline that can take years to master. ![]()
0 Comments
Leave a Reply. |