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Hector Roffo

Problem with Mesh physics shape please help!

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4 hours ago, Hector Roffo said:

I saw that video a while back but I will try and see if I upload separately if that will solve my problems, I have a funny feeling that sl Doesn't like 3ds max lol

It's the other way round. You have to remember that none of the 3D modelling programs were intended to make game/virtual world meshes and although most of them have the necessary functions somewhere, they tend to be hidden behind all the more generally useful ones. With Blender and Maya game and vr creators have quite a lot of experience between us where to find those hidden functions and how to use them. That's not the case with 3DS Max and it's not only SL, if you Google for 3DS Max and Unity you'll find many exmamples of how Unity creators have similar problems and are struggling to find anyboy who can help.

One clue to solve the rotation issues could be the axis definitions. Blender, Maya, SL, Unity and nearly all other game engines all define the z axis as vertical, in 3DS Max it's the y axis. I can't really say more than that but it's something you might want to look at.

 

4 hours ago, Hector Roffo said:

So from what I understand I would have to upload my build in 2 pieces? The roof one and the walls second?

There are several ways to split a house into practical and efficient meshes. What I would probably do with a house like this is:

  • One mesh for all the exterior walls, gables and foundations. Keep all the LoD models all but identical to the high model. You mgiht want to simplify the curvature at the top of the gable and the joint between wall and foundation but that's all. For physics: Keep the door openings (make them higher in the physics model than in the visual actually), don't let the gable physics extend more than a fraction above the roof and make sure it's no more than 1.5 m below the roof at any point. Apart from that, keep the phsyics model as simple and "boxy" as possible, only include the outwards faces and do not analyze (what I said about analyzed physics earlier only applies to single flat walls, not several walls combined into a single mesh.
  • One mesh for the roof (probably). Simplify the roof curvature, edges and apex lining as much as possible for the LoD models but not so much that there are any visible differences between them. For physics - well, we've discussed that a lto already.
  • One or more meshes for interior walls, floor(s) and ceiling(s). How many meshes you need for this, depends on how many faces there are. If each room has its own wall, floor and ceiling texture, there is room for two rooms in each mesh. LoD models: keep everyhing that is visible through windows and external doors intact, butcher away as much as possible from everything else right from medium LoD. Physics: Unanalyzed, SImple planes for floor and walls, doorways open all the way up to the ceiling. I always include the ceiling in the physics model but that isn't strictly speaking necessary.
  • Windows, door frames, floorboards, doors etc. all those little details are separate meshes.

Now, whether you should upload all the meshes as a linkset or one by one, is a different question. I definitely prefer to upload one mesh at a time. That way I avoid duplicate uploads, I don't have to worry about which visual and physics models belong together and if something's wrong with one of the meshes, I onyl have to uplaod that part rather than the whole build. Others may feel different about this and it doesn't really matter for the end result.

Edited by ChinRey

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I'm actually finally starting to understand how this works. Thank you so much for your help I am no longer going insane and finally I can move on with making my creations! :)  

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15 hours ago, ChinRey said:

One clue to solve the rotation issues could be the axis definitions. Blender, Maya, SL, Unity and nearly all other game engines all define the z axis as vertical, in 3DS Max it's the y axis.

Small correction:

Y axis up: Unity, stingray and Maya default settings (but there is the option to switch to Z up in Maya) 

Zaxis up: Unreal engine, Godot, SL and 3dsmax (and I never heard of a switch up axis in 3dsmax)

The collada exporter in Autodesk softwares is a module of the Fbx Plugin, where you can set the export up axis and that by default is Y axis up (an interoperability standard between apps, as in video production the z axis is the scene depth, not the height). So you either find this option under the collada exporter, or you will first need to do an export with fbx setting the up axis as Z in order to make this settings stick in the plug in and forget about it when using the collada exporter. It's a one time setting as it will be stored until you change it again. 

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21 hours ago, Hector Roffo said:

I am no longer going insane and finally I can move on with making my creations! :)  

Ummm, you'll have to chose one of those two, you can't have both.

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6 hours ago, Hector Roffo said:

i know and it also depends on what im making if i can get away with cube physics

We don't have cube physics for mesh in SL unfortunately. What we do have instead, is hull physics and it's not nearly as efficient

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2 hours ago, Hector Roffo said:

i thought it was called cube physics my bad 

Most everyone I know calls it "cube" physics when we use CUBES to make the physics mesh. So you will likely be understood just fine.  I have used "cube physics" on almost all my items for the last six years which includes about fifty house or so with no issues. Aquila normally uses Planes physics. For many many things EITHER will work.   

 

It takes awhile to get the hang of things. The beta grid is indeed your friend :D.  

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59 minutes ago, Chic Aeon said:

Most everyone I know calls it "cube" physics when we use CUBES to make the physics mesh. So you will likely be understood just fine.

Yes, it is understandable but there is a significant difference. The only item that uses cube physics in SL, is the cube prim. With mesh we only have access to triangles, triangle lists (not planes - that's for opensim) and convex hulls and although a convex hull can be - and usually is - a cube, the way Havok physics handles it, is very different. According to the physics weight formula, a cube treated as a hull is six times as hard to handle for the physics engine as one actually treated as a cube and it's not nearly as precise either.

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From my experience with "cube" physics is that yes it's more expensive and a little more clunky but I seem to have more success in creating successful uploads, I have yet had a successful upload with the more efficient plane physics ( not sure what the exact term is) A couple days ago I was doing planes. The outside walls were fine but when I tried to go inside I noticed that the Inner walls the physics was turned facing the wrong direction. Is it because there were two separate physics objects?

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