Difference between revisions of "MakeHuman Workflows"
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A “shader” is computer code that translates digital information into a properly rendered image on the computer screen. Different algorithms use different methods of constructing such a display. By default in MakeHuman, the viewport lighting is handled by the built-in light-sphere shader. The light-sphere shader takes advantage of support for the openGL standard provided by today’s graphics cards. What the viewer sees on the screen depends not only on the color of assets, like skin and clothing, but also on the nature of the lights illuminating the scene and causing reflections and shadows. Most downstream programs use other shader strategies, the most common of which include Phong shaders, Blinn shaders, or Lambert shaders. Because the code and conceptual design of these shaders differs from that of the MakeHuman light-sphere shader, the user should be prepared to make some adjustments in the downstream program to get the final desired effect. Some MakeHuman assets also include Normal maps which the user will want to integrate into the downstream applications rendering. | A “shader” is computer code that translates digital information into a properly rendered image on the computer screen. Different algorithms use different methods of constructing such a display. By default in MakeHuman, the viewport lighting is handled by the built-in light-sphere shader. The light-sphere shader takes advantage of support for the openGL standard provided by today’s graphics cards. What the viewer sees on the screen depends not only on the color of assets, like skin and clothing, but also on the nature of the lights illuminating the scene and causing reflections and shadows. Most downstream programs use other shader strategies, the most common of which include Phong shaders, Blinn shaders, or Lambert shaders. Because the code and conceptual design of these shaders differs from that of the MakeHuman light-sphere shader, the user should be prepared to make some adjustments in the downstream program to get the final desired effect. Some MakeHuman assets also include Normal maps which the user will want to integrate into the downstream applications rendering. | ||
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| + | When a MakeHuman material (for example, skin or clothing or eyelashes) is exported, it carries with it a limited amount of fundamental information for by the downstream program’s shaders. In an ideal world, the downstream program would import this raw information, correctly populate the variables in its shaders, and yield the same view of the human that was exported from MakeHuman. At present this does not typically happen, and the user must make some adjustments. This Wiki section is designed to help you negotiate through that process. | ||
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| + | '''Spatial transformation: MakeHuman Coordinate System, MakeHuman Skeletons, and MakeHuman Scales''' | ||
| + | |||
| + | The MakeHuman viewport is oriented so that the positive end of the x-axis is to the right, the positive end of the y-axis it up, and the positive end of the z-axis is out through the front to the screen. Other CG programs can use other schemes, so it is essential to know the coordinate system used by the downstream target at export time, if you wish to minimize the adjustments you make after importing. The settings tab allows users to work in metric units of decimeters or imperial units of inches. Downstream programs vary in their de facto units, and again, it is generally a good idea to anticipate your needs at export time rather than trying to make adjustments during or after import. It is sometimes said that these programs have no default unit. To a degree this is true. However, the default grid pattern, assumptions of other humanoid producing programs, and assumptions of the “physics systems” will often work best with the export units specified in the table below: | ||
| + | |||
| + | TABLE HERE | ||
| + | |||
| + | '''Working with Rigs and Skeletons''' | ||
| + | |||
| + | Internally, MakeHuman uses its default skeleton as the basis of mesh vertex weighting for creating the poses available on the pose tab. This rig includes a special set of bones that can be used for driving facial expressions, but as of the current release (MakeHuman 1.1.x), there is not extensive support for inverse kinematics, and animation must be done downstream in the production pipeline. Historically, MakeHuman has had close ties to Blender, but the ultimate development goal is to provide strong generic support for all the major tools used in the industry, and with MakeHuman 1.1.x, substantial progress has been made by providing weighted skeletons suited for standard use in various downstream applications. For the most part, the name of the most appropriate rig will be clearly associated with the target downstream application, but the tag filters on the Pose/Animate | skeleton tab are intended to help choose a rig suited more generally to a specific purpose like motion capture integration, facial animation, or gaming applications. MakeHuman is designed to provide the user with maximum flexibility at creation time. To provide skeletons that work perfectly with every conceivable variation of the sliders is a laudable but impractical goal. The user should get very fine results with the current approach, but should not be surprised to have to make some minor tweaks to skeletons and weights downstream, particularly with extreme character dimensions or extreme poses. | ||
==Moving Assets into Autodesk Maya== | ==Moving Assets into Autodesk Maya== | ||
Revision as of 06:37, 25 July 2015
Contents
Summary
More often than not MakeHuman users will want to move their creation into another program to continue the creation process. This section provides information on how to achieve this for common target programs. The Background and Export Example section provides some background that are common to all workflows. It is not essential to read the introduction before going straight to the program of interest, but doing so might help you understand why certain steps work or are necessary. In many cases there can be more than one way to accomplish the same thing. The method described here may not be optimal for your situation, but it should help get you started.
Background and Export Example
Introduction
Many MakeHuman users will use the work they create in MakeHuman as a component of a project completed in an external, downstream application. The most common target applications are 3D graphics applications like Blender, Autodesk 3DSMax, and Autodesk Maya or gaming engines like Unity Engine or Unreal Engine 4. In some cases, the MakeHuman user will be interested in moving just the mesh. In other cases, the user will be interested in moving a complete, posed, skeletonized character to the downstream application. The purpose of this document is to discuss the basic process of moving a finished MakeHuman asset to a downstream program and producing a reasonable facsimile of its MakeHuman appearance in the downstream application. It is important to recognize that because each application has its own way of representing 3D assets, and because each export format has its own set of idiosyncrasies, there will be adjustments and approximations in the asset transfer process.
Format Considerations
In an effort to provide the broadest latitude for user workflows, the MakeHuman development team is directing it major export support toward Autodesk FBX format and Khronos Collada format. In addition, Blender users have the option to install the independently developed .mhx2 tools, which are developed and maintained by Thomas Larson, independent of MakeHuman itself. Collada is a text-based format and is an open standard, but implementation of the standard is not as consistent as might be hoped. FBX is a proprietary standard developed by Autodesk and supported through a software development kit (FBX SDK) written in C++ and a Python FBX scripting template. The FBX standard is periodically updated by Autodesk and can be saved as either an ASCII or a binary format. Downstream programs may make assumptions about the FBX version being imported, and may limit users to either binary or ASCII importing. Surprisingly, CG assets exported from various programs as collada and FBX do not make it back into the same program as a round-trip without changes to some components of the scene. For example, this is true of FBX format in both 3DSMax and Maya for MakeHumanassets. It is also true for Blender with both FBX and collada format for MakeHumanassets. In this document, we will attempt to provide some support for dealing with this type of surprise.
MakeHuman Shader and Asset Rendering
A “shader” is computer code that translates digital information into a properly rendered image on the computer screen. Different algorithms use different methods of constructing such a display. By default in MakeHuman, the viewport lighting is handled by the built-in light-sphere shader. The light-sphere shader takes advantage of support for the openGL standard provided by today’s graphics cards. What the viewer sees on the screen depends not only on the color of assets, like skin and clothing, but also on the nature of the lights illuminating the scene and causing reflections and shadows. Most downstream programs use other shader strategies, the most common of which include Phong shaders, Blinn shaders, or Lambert shaders. Because the code and conceptual design of these shaders differs from that of the MakeHuman light-sphere shader, the user should be prepared to make some adjustments in the downstream program to get the final desired effect. Some MakeHuman assets also include Normal maps which the user will want to integrate into the downstream applications rendering.
When a MakeHuman material (for example, skin or clothing or eyelashes) is exported, it carries with it a limited amount of fundamental information for by the downstream program’s shaders. In an ideal world, the downstream program would import this raw information, correctly populate the variables in its shaders, and yield the same view of the human that was exported from MakeHuman. At present this does not typically happen, and the user must make some adjustments. This Wiki section is designed to help you negotiate through that process.
Spatial transformation: MakeHuman Coordinate System, MakeHuman Skeletons, and MakeHuman Scales
The MakeHuman viewport is oriented so that the positive end of the x-axis is to the right, the positive end of the y-axis it up, and the positive end of the z-axis is out through the front to the screen. Other CG programs can use other schemes, so it is essential to know the coordinate system used by the downstream target at export time, if you wish to minimize the adjustments you make after importing. The settings tab allows users to work in metric units of decimeters or imperial units of inches. Downstream programs vary in their de facto units, and again, it is generally a good idea to anticipate your needs at export time rather than trying to make adjustments during or after import. It is sometimes said that these programs have no default unit. To a degree this is true. However, the default grid pattern, assumptions of other humanoid producing programs, and assumptions of the “physics systems” will often work best with the export units specified in the table below:
TABLE HERE
Working with Rigs and Skeletons
Internally, MakeHuman uses its default skeleton as the basis of mesh vertex weighting for creating the poses available on the pose tab. This rig includes a special set of bones that can be used for driving facial expressions, but as of the current release (MakeHuman 1.1.x), there is not extensive support for inverse kinematics, and animation must be done downstream in the production pipeline. Historically, MakeHuman has had close ties to Blender, but the ultimate development goal is to provide strong generic support for all the major tools used in the industry, and with MakeHuman 1.1.x, substantial progress has been made by providing weighted skeletons suited for standard use in various downstream applications. For the most part, the name of the most appropriate rig will be clearly associated with the target downstream application, but the tag filters on the Pose/Animate | skeleton tab are intended to help choose a rig suited more generally to a specific purpose like motion capture integration, facial animation, or gaming applications. MakeHuman is designed to provide the user with maximum flexibility at creation time. To provide skeletons that work perfectly with every conceivable variation of the sliders is a laudable but impractical goal. The user should get very fine results with the current approach, but should not be surprised to have to make some minor tweaks to skeletons and weights downstream, particularly with extreme character dimensions or extreme poses.
