Sculpted Prims - Collision maps no longer matches it's stitching?!

[Red Barnside]

Hello, 1st: I always generate my sculpts with the "Planar" stitching. So in the past my collision map was basically a cube. But recently I noticed the "collision" edges of my sculpts are gone. After some playing around I was able to determine that the Sculpted Prim now have a collision map of a sphere, regardless of "stitching". But won't this break some old content? I for one had relied on the "Planar" stitching for the 1 Sculpted Prim staircase trick. I was using it for a Sculpted wall in a few houses...whose corners are now gone. I was just wondering if someone knew what had happened, it is a temporary glitch or do I need to pull, and rework where possible, some of my work? Does anyone know what is up with this?

[Codewarrior Congrejo]

Hello the question is kind of confusing:

'Stitching'  has somethign to do with how SL renders a sculpt and not with its collision shape.

What are Stitch Types?

Stitch types determine how Second Life interprets the edges of a sculpt map in order to render your sculpted prim.

Plane /Planar Stitching

Plane stitching is like a square piece of cloth, or like a sheet of paper. When you select this stitch type, Second Life does not assume that any of the edges of your sculptie will touch each other.
(http://robynhuffaker.com/sculptblender/tag/second-life/)

The physical shape of a sculpty has been allways: an approximated by a lopsided sphere, that is roughly the same size as the sculpted prim.

..due to it being roughly the same size of the sculpty you might just have 'felt' it being kind of box shaped.

I am not sure if there was a glitch that could be used to make SL read a sculpties collisionshape as box  instead of applying the regular sphere shaped collision body. But if so then it was probably a glitch and not as it should be. And glitches can never be awaited to be unfixed / to remain forever.

Things differ now a lot due to meshes being introduced to SL, but i can't see why it would break the old sculpty behaviours. And LL is also not planing on taking them out or changing them.

[Red Barnside]

In the past, when I would set the stitching to planar (the only kind of sculpt map I can produce), the collision for the sculpted object in question would be a "cube", that matched its bounding box. I used this in several of my builds. I know that the old "None" stitching (which is no longer an option I notice) would give the physical form of a sphere. I never tested the other types of stitching to see how they behaved. But this change is pretty noticeable...unless people stay dead center of my stairs, they are going to fall through what used to be "solid" at the corners.

[Codewarrior Congrejo]

I didn't fiddle with sculpts in ages. I said good bye to them the moment mesh was finally introduced.
For many reasons i have never been a fan of using this method to create any 3D content. (not saying they did not serve a good purpose in SL, but yeah too limited, too restricted and too many issues in matters of rendertime, shaping, modeling etc)

What the other stitching types did you can see in the link i included in the former reply. (and the 'stitching' was generally how its rendering your sculpt - the relation to it being assigned to a box shaped physic shape is new to me- even the wiki says that its collision shape is  to this date still  a sphere)

But yes, with mesh now a lot things have changed. Since you now can include (finally) your own physics shape into the model.

I tried to find any posts or threats or infos on the web regarding sculptphysics shapes being changed. but could not find anything.

[Codewarrior Congrejo]

Hold on, found something: http://community.secondlife.com/t5/Mesh/physics-shapes-of-sculpted-prims/td-p/920181

okay this entry makes it clear, it's due to being in need to actively set a physics shape / type now:

When i set Physics type to "Prim" (which seems to be the dafault for Sculpties) nothing shows up in the viewers physics shape display.  But when i set it to "Convex Hull,something shows up (see right most image).

So whatever ways u have used before to trick SL out of the usual Sphere, you have to befriend its new system now and choose one of these settings instead.

[Drongle McMahon]

To be precise, the collision/physics shape of sculpted prims is, and always has been, the convex hull of a torus with equal inner ans outer radii (that is with no hole). Somewhere in the old forum is a thread where this is confirmed. (This is the thread Code linked to.) One consequence of this is that when you have a flattened sculpty, the apparently solid area depends on which is the flattened dimension. This is illustrated in the picture, where the corners you can fall through (yellow bounding box) are more obvious when the z axis is squashed (left) than when one of the others is squashed (right).

 

These sculpties both use the full range of the RGB values and therefore fill the bounding box. The collision shape always fills the bounding box, but if a smaller range of RG and/or B is used, then the box will not be filled by the visible sculpty. In that case, the collsion shape will be larger than the visible shape. This would stop you falling through it up to, and even beyond the visible edges.

[Red Barnside]

Still conducting experiments, but something still just isn't right..or at least like it used to be. Will post as I gather more info.