Land impact/ physics question

[Dilbert Dilweg]

I am working on making a bed. It is a pretty basic setup and the vertices a little over 2000.

Set to convex hull the land impact in only 6. But when I change the object settings to PRIM, the impact jumps to 148. Is this normal behavior? Or is something I may be doing wrong? Or is this a SL bug that I am beating my self up over?

Any help would be greatly appreciated

[Drongle McMahon]

It depends how you made the physics shape. Anyway, you clearly need to make a much simpler mesh for the physics shape. Probably just a single box each for the base and a headboard if there is one (or rails etc.). Upload this on the physics tab. Have them non-overlapping and click "Analyse" but not "Simplify". Make sure the boxes between them fill the same size bounding box as the visual mesh, otherwise it will get stretched to fit.

[Dilbert Dilweg]

Thank you for the fast reply Drongle.

That is what is confusing me. My physics shape is one simple cube with 1 loop cut with an extrusion for the headboard. The physics shape only has 2 hulls and 16 verts.

I managed to reduce the impact to 4 but when i set the physics shape to prim I still get a Land impact of 146.

So i am not sure what the problem is here.

Do I need to make a different physics shape for the blanket?( I would think not). That is the part that has the most verticies

 

EDIT: the bed only has 1000 verts

[Drongle McMahon]

You have to set type prim to use any supplied physics shape, so that part is correct. If it's decomposed ("Analyze"), which it must be to get the hull and vertex counts, that physics shape should have a weight of 0.72. So something is wrong. I'm not sure what you mean by the blanket. Is that a separate linked object? If so it will have it's own physics shape that might be the culprit. Set it to type "None" (it can't be the root of the linkset for that)?

[Dilbert Dilweg]

No the blanket is not a seperate linked object. It is just the part of the mesh that has the most faces

 

But I uploaded one just now and wow! I set the  method in step 2 on the physics tab to "surface" instead of solid and what a difference. My upload cost was only 15 and the land impact was only 5

But standing or sitting or walkiing on the bed does not give be the desired shape . Its like waliing up a ramp to the headboard instead of it being formed to the shape I had set.. I did make sure the shape was not bigger than the actual mesh also.

 

[Dilbert Dilweg]

Heh . Now I can not get past crashing every time I try to upload the same file i have been uploading .

But I think maybe my physics shape was extruding out a a bit and it may have streached it from the foot board to the headboard and made it like a ramp. I hope that is the case because any other setting other than surface gives me a massive increase on the Land impact..

Thanks for your help Drongle i appreciate it . Hopefully when I get the viewer sorted or use another one I can give it another try lol.

 

I did not realize the the system would reshape the physics shape if it was over lapping a little. . I shal see.

[Drongle McMahon]

I just tested a half-finished bed I have with a physics shape of four boxes (base, headboard, footboard, pillows). Using surface decomposition, that has a physics weight of 1.7. These were separate non-ovelapping boxes (but all one mesh). I think there must be something very odd about you physics mesh, but I can't guess what it might be.

[Nalates Urriah]

You could bring a copy of the bed to the Content/Mesh UG on Monday. Nyx will often look at strangely behaving mesh items to see if it is the object or a bug in the system. Nyx will need to see the .dae file.