Upload physics from file - problem

[Zoran Elton]

How to make this C shape (wall) physics, but hollow inside and in 2 corners (around)?

[Frawmusl]

Export a simplified version of the wall, following where it would collide and then in your physics tab upload from file and upload the simplified version. 

Also, Theres a couple of edgeloops there you could remove to optimize it more -wink-

[Zoran Elton]

I want to drive wehicles and walk on wall-hill.

How you mean  simplified version? To remove edges?

[Frawmusl]

So on this fire place it has a decent amount of detail, but I created a simple outlining version on where I want the avatar to collide with it. and uploaded that in the physics so it didn't calculate a heavy physics by the original object being triangulated

[Zoran Elton]

Im undrestand now what you mean when you say  decent amount of detail.

 

But my object is C shaped, not simple like your =(

I want to import that part and make copy- simmetry for 2nd wall....that wil look like circle , I want to walk on wall and inside circle (2 C walls).

 

Is that possible?

 

 

[Kwakkelde Kwak]

Make the physics shape similair to the one above, then like Frawmusl said, upload that as physical model to SL, don't use "analyze". Don't forget to set the physics type of your object to "prim" after uploading.

[Drongle McMahon]

It sort of depends how much LI you want to maim at. Your mesh is essentially a set of slightly distorted cube-like objects, one for ech section, 64 of them I think. The most accurate physics shape would consist of exactloy those 64 pieces. In theory you can get this by speciofying your high LOD mesh in the physics shape tab of the uploader and pressing "Analyze". From that mesh, it should produce 64 hulls which are exactly those 64 pieces. The physics weight for that would be a size-independent 64 x 0.36 = 23.4. If that's higher tha the download weight, then that will be your LI.

Unfortunately, the "Analyze" tends not to do whet you want with complicated mesh like this. To be certain of getting the 64 pieces, you may need to make a new mesh where each piece is a separate box, with the tiniest gaps in between, so that the analyze sees them exactly the way you want. ( I don't mean separate meshes - the boxes are separate, but all part of the same mesh object). Using that instead of the high LOD should work.

However, if you want a lower weight (and your download weight is already lower), then you can combine some of the pioeces into a smaller number of boxes. Choose the ones where the top surfaces are at the smallest angles to each other. That's sort of equivalent to removing some of the edge loops. If you nremove thoise edgeloops from the main mesh too, the shape will be accurate again, and you may lower the download weight too.

Oh! I just thought that you may have (sensibly) no bottom faces on this thing. In that case, the first suggestion won't wor at all. You will need to add the bottom surfaces to the high LOD mesh to make the physics mesh. Same thing for all the pieces if you find you need to separate them. Also, try both "Surface" and "Solid" when you press "Analyze". They behave a bit differently.

... yes ... see Kwak's picture to understand the edge loop reduction.

[Aquila Kytori]

yes

You have to make a very simplified version of your wall and export it as a seperate Collada file which you will use in the second page of the mesh uploader.

 

Upload your wall.dae as normal in the Mesh Uploder window then go to the second page , called Physics and there upload your wall physics .dae file .

Don't touch any of the other buttons on this page , Just hit the Calculate weights and fees button and then Upload .

Rez your wall and then Edit it. From the Edit>Features tab change the Physics Shape Type to Prim.

You should now be able to walk along the top of the wall and inside the inner curved part.

 

Edit: wow and i was working as fast as i could and both drongle and Kwakadle got there first lol .

[Zoran Elton]

Thank you all.

Im upload same model Dae. file in === Upload physics from file.

Bottom poligons deleted.

And it works.:matte-motes-oh-rly:

But I dont know why  this option is not by Default? If somebody upload doors or something similarly, mesh must be physics and hollow inside. This option is confusing.

I pay only 5 Lindens above for physics file. I was scary to reduce edges, because I want to walk and drive, normallyl on wall, without decline inside.

 

Thanks again problem solved.

 

[Drongle McMahon]

Kwak says don't use analyze. That depends on the size of the faces you dedcide on for your physics mesh. Better to try both and see which gives the lower weight. If you don't use Analyze, then don't put the bottom faces on the pieces (or take them off if they are there to begin with). Not using Analyze will give you a triangle-based physics shape, The weights of those get higher the smaller the triangles are.

There is a slight disadvantage in that you can occasionally penetrate into the inside of these shapes. If you do that with a hull-based (Analyze'd) shape, you will get nudged out again, but if you do it with a triangle-based shape, you will be stuck inside. The rislk of this happening is small though, unless you collide with the shape at high speed. So if it gives you a lower weight at whatever your final object size is, it is probably the better choice.

[Drongle McMahon]

The default vfor physics is a single convex hull for the whole mesh. This is always made and is what is used if you set the shape type to "Convex hull" inworld. If you specify a physics nesh (LOD mesh or separately uploaded) the default convex hull will be made from that mesh. If you don't, the default convex hull is made from the low-LOD mesh. The reason the high LOD mesh is not used as the default shape is that it will generally give excessively high physics weights. Even the default can still give high weights for complex meshes, which is why it uses the low LOD mesh.

[Aquila Kytori]

its not a "Default" option because the idea is to use a Simplfied version of the high LOD mesh so that the physics engine will have less calculations to do and so there will be less lag .

More often than not the physics shape does not need to be as detailed as the High LOD model.

Also for complicated models if u used the high LOD as physics then the LI can be very high

[Kwakkelde Kwak]

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Drongle McMahon wrote:

Kwak says don't use analyze. That depends on the size of the faces you dedcide on for your physics mesh. Better to try both and see which gives the lower weight.

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I just don't like the way avatars hover above analyzed physic shapes. So since the wall was ment to be walked and driven on, I figured triangles are preferred over hulls. If the wall was ment to keep vehicles on one side, I'd probably use hulls instead.

[Drongle McMahon]

"I just don't like the way avatars hover above analyzed physic shapes."

I was already thinking that would probably be the next question. :matte-motes-big-grin:

(Although, I get hovering above triangle-based shapes too.)

[Kwakkelde Kwak]

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Drongle McMahon wrote:

 

(Although, I get hovering above triangle-based shapes too.)

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I noticed that recently, but a couple of months ago when I often tried both ways for walkable surfaces, the hulls made me hover and triangular based ones didn't (or at least a whole lot less). Maybe they changed something?