What's New in Character Effects and Environment Building

XGen

New shading nodes

New shading nodes provide more ways to customize your XGen hair shader network. You can now color and texture XGen hair and other primitives using custom shaders or Maya standard materials. These new shading nodes now let you:

• Control the color of your hair shader with Ptex-based textures. Connect a new xgen_ptex_lookup node to your XGen shader network to color hair with any Ptex-based texture or image file.

  See Assign Ptex-based textures to Descriptions.

• Color hair from root and tip with a new xgen_root_tip_color_blend node. This node lets you set hair root and tip color, and then output the colors as a single channel to your XGen hair shader.

  See Color hair root and tip.

• Vary color along the length of each hair. Connect a new xgen_hair_length_mapping node to your shader to control rendered hair color using a 2D texture ramp.

  See Assign ramp 2D textures along spline length.

XGen presets

You can now save hair and fur grooms and instanced geometry as XGen presets. Start hair and fur grooms with presets or use them to manage shot-based hair styles, landscapes, and environments. Presets are topology independent, so you can apply them to low and high resolution versions of your character mesh or to different mesh shapes. Add your custom XGen presets to the new XGen Library. The XGen Library also includes default fur and grass presets, which you can select to quickly apply them to character meshes and other mesh objects.

XGen presets include all the Description settings, such as guides, modifiers, and shading networks, in one file. This makes them ideal for transferring and sharing grooms and instanced geometry within your production pipeline. If you apply a preset that contains Ptex-based mask and region maps, Maya creates a Ptex map expression with the necessary connections. You must repaint the map values on the preset's target mesh.

• Save hair fur or instanced geometry as XGen presets
• Create hair or fur using an XGen preset
• Add presets to the XGen Library

Create custom shapes from spline primitives

A new Spline Width Ramp lets you vary the width of spline primitives along their length. Use the Width Ramp to create custom shapes, such as feathers, scales, leaves, and other vegetation, from spline primitives.

• Shape splines by varying width

New default XGen hair shader

A new mental ray xgen_hair_physical shader for spline primitives improves rendering of hair and fur grooms. The new default hair shader is fully supported in Maya Viewport 2.0, so you no longer need to use a surface shader to display color and lighting effects before rendering. The xgen_hair_physical shader material is based on the Marschner hair shading technique.

Sculpting guides

You can now shape and scale XGen guides using a new brush-based Sculpt Guides Tool. This tool simplifies your guides-based workflow for spline primitives by letting you sculpt guides without selecting vertices or using XGen Utilities. Use the Sculpt Guides Tool with spline primitive guides only.

Sculpting Guides Tool options let you adjust brush size, toggle Lock Length on and off, and have the brush actions affect all Descriptions. Access the Sculpt Guides Tool from the XGen Shelf by clicking this icon: .

• Shape spline primitives using XGen guides

Maintain links between curves and guides

A new Preserve Dynamic Link option in the Curves to Guides utility improves guides-based workflows by letting you:

• Reshape source curves and have the edits automatically applied to the guide shapes.
• Use one set of curves as the source for guides in multiple Descriptions. Reshaping these curves reshapes the guides in all linked Descriptions.
• Drive guide shape and animation using nHair dynamic output curves.

See Animate guides using nHair dynamic curves.

Save groom edits to delta files

A new delta file workflow lets you save groom edits without altering your source Description. Use XGD delta files to make shot-based changes to hair and fur grooms while preserving the original version. Revert back to the original groom by deleting or relocating the delta files.

See Save groom edits to delta files.

Performance improvements

XGen performance improvements include:

• Enhanced viewport tumbling for better interactivity while working with high-density Descriptions.
• Multithreaded primitive generation, modifier processing and patch evaluation.

  An XGen Threading option in the Maya Preferences lets you toggle multithreading on and off.

• Faster primitive previews.

Workflow improvements

Improvements to the XGen guides workflow now let you:

• Use Soft Selection to select guide vertices.
• Delete guide vertices.

Updated XGen development kit examples

Updated examples for XPD file implementation have now been added to the Maya install directory. These examples can be found in the following location: C:\Program Files\Autodesk\Maya2016\plug-ins\xgen\devkit\xpdSamples.