New World Notes has a story on building with mesh building blocks in Cloud Party. See: Cloud Party Adds Mesh-Based, Collaborative Building Blocks Which Sound Super Superior to SL’s Prim-Based System. Win the contest and get US$50 of Cloud Party coin.
Originally I thought this was a feature that many have asked for in Second Life. The feature people ask for would allow those not interested in using Blender or 3DS to build with custom mesh in SL. They would be able to edit the individual vertices of an object. But, that is not exactly what they are getting in Cloud Party. The following video shows what is being added.
While this does not allow users to tweak individual vertices, it does add an easy way to hook primitive shapes together. In SL we use Third Party Viewers (TPV) that have alignment tools to set cubes next to each other. In the SL Viewer we have to do math or use something like Prim Docker to fit cubes together. But, that process does not remove any of the hidden faces or vertices. My understanding is that in Cloud Party using blocks does omit the hidden parts.
The really neat feature in Cloud Party is that the new Block Tools work with mesh items made in Blender or another 3D modeling programs.