# Difference between revisions of "Talk:Prim and Object Hierarchy"

## Transcript of Google TechTalk section

Google TechTalk, March 1, 2006 - Glimpse Inside a MetaVerse: The Virtual World of Second Life - Philip Rosedale and Cory Ondrejka - Transcript from video time [30:10]:

Audience: Can you improve things by having a hierarchical model? Like for instance those dominos are all replicas of one another, and then the dots on the dominos are replicas, that way you wouldn't have to transmit all the vertices of all the objects.

Philip: Yep, that's stuff that we're, you know, some small pieces that we've done and more stuff we're doing. So we're building hierarchical models and optimized stuff. 'Course, as like one of my big design decisions at the beginning was "Let's not try and do that, it's just crazy, we can't do hierarchies.", but ...

Cory: It's one of the very few blunders we made, actually, not having hierarchies, it seems like that.

Philip: Yeah, one of the only things like, the coolest things that you can't quite do yet do in Second Life is you can't have like a big jointed monster, you know walking around. You can if you wanna really work at it, but it's terribly hard, so we need to add that kind of hierarchy, but that stuff's, I mean, we understand how to do that. We have a great, we have a pretty good size team.

Morgaine Dinova 13:03, 22 January 2009 (UTC)

## Prim and Object Hierarchy

I agree, 100%. I've noticed that many SL 3D concepts come directly from basic 3D graphics libraries such as OpenGL. Wouldn't this correspond to a kind of scenegraph?

Hi, I think we just need one new value and two new functions.

A "second parent" or "minor parent" or "???" for every child prims, that is UUID of and other child prim (or by default the real parent prim)

And two functions : llSetLocalRot2() == the same that llSetLocalRot() but with second parent. llSetPos2() == the same that llSetPos() but with second parent if the prim is a child prim.

Then we can move all child prims with their "second parent" or with the real root prim. When a child prim move, all child prims that have this one as second parent move too, like child prims move with root prim actually.

Rohacan Hirons. (Sorry for my poor english, I hope you'll understand me XD)