Nuclei-Foundation / GLTFblenderGSOC

GSOC 2017 - Blender Organization, Implementation of GLTF Project Repository.

Blendergltf

About

Blendergltf is an addon project for Blender that adds the ability to export to the [glTF format] This addon started its life as part of the [Blender Real Time Engine addon] in order to provide a convenient way of streaming scene data to real time engines. As interest has grown in glTF, the glTF exporting code of the Blender Real Time Engine addon was moved into this repository to be used as both a Python module and a Blender addon. While Blendergltf has support for most of the glTF 1.0 spec, it is not yet well tested with the various engines and importers that can consume glTF.

Installation

1. Download the zip file.

2. Launch Blender, click File -> User Preferences..., and click the Add-ons tab at the top of the User Preferences dialog. Then, click the Install from file... button in the bottom margin of that dialog. Select your ZIP file to complete the install.

3. In the left margin there is a Supported Level selector, click on the Testing level. If you have other testing addons installed, you may need to enter gltf into the search box at the top of the left margin.

4. You should now see Import-Export: glTF format as a block in the body of the preferences dialog. Put a checkmark on this row to activate it.

5. Finally, click Save User Settings to keep the changes. Note that any other settings changes you have made to Blender may also be saved.

Usage

Load a scene you wish to export to glTF, and click File -> Export -> glTF (.gltf). Some glTF export options will appear in the lower-left margin, and a file dialog will ask for the location to save the exported file.

Add-On Settings

Forward and Up

Together these settings define the axes convention of the glTF output. Conversion from Blender's Z-up convention to the target convention is handled by inserting an additional node with an appropriate transform matrix as the root node for a scene. If no conversion is necessary, no nodes are added.

Export Hidden Objects

If this setting is enabled, nodes that are not on an active layer in Blender are excluded from the glTF output.

Selection Only

If this setting is enabled, nodes that are not part of the current selection in Blender are excluded from the glTF output.

Export Shaders

If this setting is enabled, the GLSL shader for a material will be exported. This will be a version 130 shader if the profile setting is set to Desktop, and a version 100 shader appropriate for use with WebGL if the profile setting is set to Web. If this setting is disabled, no shader information will be exported and the KHR_materials_common extension will be used instead.

Apply Modifiers

If this setting is enabled, any modifiers will be applied to the mesh data. If the setting is disabled, no modifier information will be exported.

Interleave Vertex Data

If this setting is enabled, all of the data for a single vertex will be contiguous in a mesh's buffer. If it is disabled, all vertex properties of the same type will be contiguous in a mesh's buffer (e.g. all positions, then all normals, then all texture coordinates). Usually this setting can be left alone, but some glTF loaders do not support interleaved vertex data.

Embed Image Data

If this setting is enabled, image data is embedded into the glTF output as data URIs with a PNG mime type. If this setting is disabled, the path that Blender uses for the image is stored in the URI.

Profile

This setting controls the profile in the asset's profile property in the glTF output. It also affects if shaders are exported for OpenGL or WebGL.

Export Physics Settings

If this setting is enabled, a custom extension (BLENDER_physics) is used to write bullet physics data into the glTF output.

Export Actions

If this setting is enabled, a custom extension (BLENDER_actions) is used to write animation data as individual actions instead of writing animation data as one block of data as described in the glTF specification. Currently, if this setting is disabled, no animation data is included in the glTF output. Regardless of this setting, skin data is included in the glTF output.

Pretty-print / indent JSON

If this setting is enabled, tabs and newlines are inserted into the glTF output to make it more human readable. This option is useful if you wish to read through the glTF output. Otherwise, it should be disabled to make the glTF output smaller.

Recommended Settings

Three.js

Interleaved vertices support was added in version 83. If you are not using a recent version, you should disable the Interleave Vertex Data option.

Roadmap

The current development goals, roughly in order of priority, are:

• Improve three.js support (including shaders)
• Improve Cessium support (including cleaning up extension usage)
• Improve BabylonJS support
• Implement an extendable extension system to more easily allow custom extensions
• Improve GUI and user experience of the addon (including documentation)

How to Contribute

The most helpful way to contribute right now is to try and use the output of Blendergltf, and report any issues you find. This will help us identify where work is still needed, and it will help make the addon more robust. If you want to contribute code, there are likely some tasks floating around the issue tracker. If writing documentation is more your thing, we have some undocumented glTF extensions.