Sketchlife

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What is Sketchlife?

Sketchlife is a system which allows you to build for Second Life using SketchUp.

Most 3D modelling tools use meshes (vertices connected by edges which define faces), whereas Second Life has adopted solids, referred to as primitives, to be their indivisible building blocks. This guarantees that there won't be any stray polygons flying around, but it also prevents mesh models from being imported automatically.

The in-world modelling tools in Second Life are quite good, but they are stone age compared to the 3D modelling power tool that is SketchUp. SketchUp is free. (Thank you Google.)

Therefore, if we can't bring SketchUp to Second Life, we'll bring Second Life to SketchUp.

Sketchlife Hello World video — start here

This video shows a very simple model of the words "Hello World" being built and uploaded using Sketchlife tools. It demonstrates the process: press "Export", copy and paste the model key, drop the textures into the box, and, finally, copy and paste the build key. The process is the same for all models.

In a few words, Sketchlife is a tool to speed up the SL building process. A Sketchlife user will have an edge over even the most proficient builder who uses the online Second Life building tools exclusively. Sketchlife does not replace all of the in-world tools, it replaces those tools which are used to make up the bulk of Second Life buildings. After a model is imported, online tools can be used as always, to add the extra few details that may be necessary.

Examples

The most complicated model imported to date is St. Basil's Cathedral, originally modelled by Arrigo Silva and featured on Google Earth.

Teleport: click here (this is a SL-URL).

There are more screenshots on the Examples page.

Components

1. The most important part of Sketchlife is the SketchUp extension. It is a Ruby script which uses the API provided by SketchUp to add several tools on a toolbar (inside SketchUp).

From left to right:

1. Box primitive tool.
2. General cylinder primitive tool.
3. Simple cylinder primitive tool.
4. Arch tool.
5. Sketchlife bucket.
6. Select All Sketchlife primitives.
7. Remove non-Sketchlife primitives from current selection.
8. Export selected primitives to Second Life.

2. The second most important element of Sketchlife is the Sketchlife Importer. It is an object in Second Life which looks like this:

It builds the object that you import.

Pros

The main strengths of using Sketchlife rather than the conventional building tools in Second Life are:

• You draw the prims by picking points in the model, one after another (this is the SketchUp way). The inference engine in SketchUp makes it easy to accuretely snap to points, edges and faces of objects while positioning, scaling and rotating.
• You can position textures using SketchUp's phenomenal texture tool which makes draping one texture over multiple prims straight-forward.
• Sets of prims can be hidden (by putting them on a hidden layer) and unhidden in a few clicks. This can be a major timesaver when building a structure of moderate complexity.

Cost

	Fee
Per primitive:	L$1
A model containing only one prim with at most one textured face can be imported for free.

For large, fully-textured models we have imported, the price of using Sketchlife was approximately the same as the price of uploading the textures. This combined cost is in all cases much smaller than the time investment required to build any given model. Also, the ongoing cost of land hire greatly outweighs this cost, even if everything on a parcel was to be constructed with Sketchlife.

The free option allows you to experiment.

Demonstration video

This video shows another simple, but this time useful, example of how to use Sketchlife. In this example I make a tile, replicate it and then stretch a texture over it. This application may be useful in itself, but the video is also good to watch for getting to know Sketchlife, as it shows the whole process of getting a model done, from start to finish.

Teleport if you want to have a look: SL-URL link.

If you would like to do something like what is shown in the video, here is a (zipped up) SketchUp file, with 26×26 tiles covering a 256 metre square, with some overlap. That covers a whole island exactly, so you will probably want to delete some of the tiles. The overlap and transparent sides of the tiles are intentional, as otherwise you will get flickering pixels as you move the viewpoint. (The UWA crest from the video was updated to have overlap and transparent sides.)

Process (briefly)

• First you will need to build a new model (or recast an existing model) using only Sketchlife primitives — those provided by the drawing tools from the toolbar. See the Tools page.
• The primitives can be textured using normal SketchUp tools, or using the Sketchlife bucket (which is often more convenient).
• Then the prims making up the model should be selected and the export button (with the red arrow) pressed.
• This will bring up a web dialog. It will first inform you if there is anything wrong with the model as it is.

From here, follow the prompts of the web dialog, and the Sketchlife Importer. Below is a summary of what will take place.

• Then it will give a code for you to say in Second Life. Copy and Paste it while near your copy of the Sketchlife Importer.
• (Optional) Back to the web dialog, if you have used any textures on any of the prims being exported, it will provide an option to write the texture files to disk. Select a directory for textures to write them there (or skip this step).
• (Optional) Upload the textures using the normal Second Life upload process (Upload Image or Bulk Upload).
• (Optional) If you have used textures, the Sketchlife Importer would have rezzed a texture box, which looks like the one on the right. Drop the textures onto the texture box.
• Finish with the web dialog by uploading the model data to vrshed.com.
• The web dialog will give you a build code. Say it in Second Life near your copy of the Sketchlife Importer.
• You will need to grant the Sketchlife Importer permission to withdraw money and then pay it the cost that it quotes for the model. It will only withdraw money when the server confirms PAID status.
• It will then build the model.

The above description is expanded in the Details section.

How do I get it?

1. If you don't have SketchUp installed, download and install SketchUp.
2. Download the file sketchlife.zip and unzip it directly into the SketchUp/Plugins/ directory (which can be different for different users, for example C:\Program Files\Google\Google SketchUp 7\Plugins\ on Windows, and Macintosh HD/Library/Application Support/Google SketchUp 7/SketchUp/plugins/ on Mac).
   The contents of the ZIP file should go into this plugins directory. This is a file called sketchlife_nc.rb and a folder called Sketchlife.
   (If you need more help with this step, see this page for Windows users, or this page for Mac users.)
3. (Re-start SketchUp.)
4. In Second Life, teleport to The University of Western Australia island, where you will find a desk from which you can get a copy of the Sketchlife Importer.
5. Copy it. Now you have everything you need.

This is the desk near the UWA teleport location:

More information

On the Tools page, we have a description of how to draw prims and use other tools.

The export process (from when the Export button is clicked) is fully described on the Details page.

More information about how Sketchlife has been implemented are on the Inside page.

In the media

• Sketchlife has been covered in a New World Notes article, in fact they approached me within a few hours after Sketchlife was released. Now that's journalism!
• There is an article on the Electric Archaeology blog.
• An article on the Second Life Education in New Zealand blog.
• The post in Second Life forums where I announced Sketchlife. (Login required.)

Evgeni Sergeev
Friday 03 July 2009 15:53 (Western Australia Standard Time)