How To Upload Mesh
From OpenSimulator
How to Upload Mesh
What fields must you fill in on the model upload dialog?
These are the values that I always fill in, some are only recommended, others are absolutely necessary for physical structures like buildings. Since OpenSim 0.9.0 and ubODE many people have had problems with mesh they upload, even with mesh that were uploaded in previous versions. These problems are all based on the Physics Level of Detail, pay special attention to that section below. Model Name: (recommended)
- This model represents... (recommended)
- Level of Detail (highly recommended)
- Physics tab
All other fields in the Upload Dialog can be ignored
Model Name:
This field is the name the mesh will have in your inventory. Come on! Fill something meaningful in.
This Model represents...
Pick the closest one. I'm not sure this affects anything. Many mesh are used as part of something else so the most common choice is "Building Component". This is not used by OpenSim, but some viewers could in theory use if to select different meshes processing/optimization parameters
This model represents… has only one function "MUT_Unspecified" Specified in llmeshrepository.cpp
Level of Detail
This determines what your mesh looks like as you view it from farther and farther away. The default values make objects look bad from a distance, I recommend a little higher than that. Some people over-react to this by setting all of them to the max, I don't recommend that either.
- The HIGH setting defaults to all your triangles and vertexes. You see this when close to the mesh.
- I recommend increasing the MEDIUM setting to half the triangles of the HIGH setting.
- I recommend increasing the LOW setting to half the triangles of the MEDIUM.
- I recommend increasing the LOWEST setting to half the triangles of the LOW.
Physics tab, Step 1 Level of Detail:
View your model in the Preview window, it will initially be gray. Rotate it (with CTRL-LEFT-MOUSE-DRAG) and zoom it (with SHIFT-LEFT-MOUSE_DRAG) until you can see it at a good angle. As you select different Physics Level of Detail values, yellow triangles appear on top of your model.
- You can create your own model for physics and select it here
- Or you can select a LOD from the visual part.
- Or you may not select any thing on this tab, or leave as "CHOOSE ONE"
Note that some visual LOD may not be good for physics, because of different optimization criteria, so you may need to choose HIGH for a proper collision shape.
- If a yellow triangle appears inside a doorway in a building in the preview, you will not be able to walk through that door.
Not selecting anything on physics tab (or leaving it as CHOOSE ONE") is a valid option because current viewers will always upload a crude physics shape that follows the outline of your mesh, with holes filled. This is collision shape you will get when setting Physics Shape Type to CONVEX, also the initial default after upload. This is a valid option if that crude shape is good enough for your needs, or you will only use the mesh with Physics Shape Type set to None, for example on vehicles or other objects that have the collision shape defined by simple and faster colliders like Boxes or true spheres. It is also valid for Avatars since Opensimulator physics engines use a special collider for them, ignoring the mesh.
Calculate Weights & Fee
Press this button after setting the four fields above. This may take a long time, may never finish, or give you errors. What can you do about that?
- If you don't need to walk on your model or walk through the holes, try setting the Physics Level of Detail to LOWEST or CHOOSE ONE (this last one means none)
- Setting the Physics Level of Detail to HIGHEST sometimes allows a model to load successfully when other settings do not.
- If you must have a physics model, try uploading it on another region running BulletSim, ODE, an older version of OpenSim or some combination. Carry the mesh home in your suitcase if necessary.
- Your model may have gaps, tortured quadrangles or too many vertexes. Try simplifying it or cleaning it up and then upload it again.
Upload
The Calculate Weights & Fee button will change to Upload, press that. Your mesh will be uploaded and appear in your Objects folder in inventory. This may take a long time, may never finish, or give you errors. See the suggestions above.
After You Upload A MESH
Rez a copy and check it out
- By default on 0.9 a new mesh is rez with Physics Shape Type CONVEX
- Depending on what version of OpenSim you have, what physics engine it is using and other parameters, your mesh may rez in a mode that you don't expect.
- Depending on whether your mesh is used as a root or a child prim, it may rez in a mode that you don't expect.
So rez a copy of your mesh, link it to something else if necessary, edit it and look at the Physics Shpe Type in the Features tab in the build dialog.
The Physics Shape Type has the following values:
- NONE means your mesh is phantom (if a child prim). Root prims still use the PHANTOM setting in the Object tab for this.
- CONVEX HULL means your mesh acts like it has been shrink-wrapped with an invisible shield. You cannot walk through holes in it.
- PRIM means your mesh "collides" like the yellow triangles you saw in the Preview picture while setting the Physics Level of Detail
Why Do Some Mesh Not Allow Physics Type PRIM?
If you uploaded your mesh and forgot to set the Physics Level of Detail to any value (left it as CHOOSE ONE), you may never be allowed to set PRIM.
- In older versions of OpenSim, with BulletSim or ODE physics, if you forgot to set the Physics Level of Detail then HIGH was assumed and Physics Type PRIM worked.
- In OpenSim 0.9 with ubODE physics, if you forgot to set the Physics Level of Detail then YOU WILL NEVER BE ABLE TO WALK THROUGH HOLES IN THE MESH.
- If your mesh was loaded in an older version of OpenSim, did not have a Physics Level of Detail and has worked fine for ages, when you update to 0.9 with ubODE YOU WILL NO LONGER BE ABLE TO WALK THROUGH HOLES IN THE MESH.
- If you still have the DAE file, on OpenSim 0.9 with ubODE you must upload the mesh again and this time REMEMBER TO SET THE PHYSICS LEVEL of DETAIL
- If you no longer have the DAE file or you got the mesh from some unknown source YOU ARE S.O.L.
- If you got the mesh from someone else, ask them to give you a new copy after SETTING THE PHYSICS LEVEL OF DETAIL
- You may also build a physics collision shape adding basic transparent prims, in fact this is a good option for vehicles for example.
See the uploaded physics mesh
Some viewers like Firestorm allow us to see the physics meshes of objects in world ( Menu Developer -> Render Metadata -> Physics Shapes ) so you can use that to check if the upload was in fact correct, viewers do odd things occasionally.. you can select Physics shape Type Prim (if present) and Convex and observe ( note this is very heavy and viewer may crash if there are many prims in view )
