MESH - Texture face problem

[meriilion Vyper]

Come across a problem with mesh,. I play around building sailboats, and have styarted to convert them to mesh which was fine till i started makingf mesh sails wuith multiple faces.

The sails are made visible or hidden by using the usual ALPHA transparency LSL commands

 

So boat rezzes - all sails are transparent - no problems

Sit on the vehicle and a selection of the faces now become visible, so I have partiall visibile sails (I have kept the number of faces to four for the sails)

I can issue a command to lower the sails and they all become transparent again, so I have a get around and I am discussing the problem with the creator of the script, but was wondering is there were any special issues with mesh faces and scripts, face 0 seems to be the dominant face that appears

 

 

[Cathy Foil]

There shouldn't be any problem with controlling the alpha transparency setting of a mesh face with using a script.

You can have up to 8 faces or textures per mesh so 4 shouldn't be a problem at all.  You just need to know the face number of the particular sail you want to be visible or invisible.  I am assuming that all the sails are one mesh and that you just want to make each one its own face.

If you log on with Phoenix Firestorm finding out the number of each face is easy.  Just rez the sail mesh and then with the edit tool select "select face" option and click on each sail.  It will tell you the number of the face just under the "Link" button.

Then just drop your script into your mesh and set the face number for the appropriate sail in the script.

I hope that helps.

[meriilion Vyper]

Thanks for the reply

 

Yes each sail is a single mesh, with up to four faces, and I have been able to identify the faces, and can control the alpha transparency using the ALLSIDES okay if I use the external script commands. lower/raise.

The odd thing is that when you sit on the boat, it seems to trigger certain faces to appear visible (so you have part visibile sails), although there is no script or command to actually trigger the event or make those particular faces suddenly appear. then i can clear the bug using the normal commands. Never had the problem with prims, only with mesh

 

 

[Toysoldier Thor]

Its surely not unheard of for SL textures to do wonking things.  There is a long standing bug (over 4 years old) that is a huge pet peeve of mine since it effects a lot of my landscape customers whereby a texture on a prim that is animated and has a repeat H and V pattern not the default (i.e. not 1 and 1) will return to the default H and V pattern of 1 and 1 if the viewer leave the proximity of the animated texture for a few minutes.

This bug has been 100% proven and yet has been a bug for over 4 years.  https://jira.secondlife.com/browse/SH-2947

So it would not surprise me that texture behavior on a new type of surface on an SL mesh object would encounter unexpected results.

If it is a bug.... the jira above is clear proof that LL will likely not fix the bug.

[Medhue Simoni]

Well, I can't really help with the texture issue, but I will throw some ideas at you.

Making parts of things in a build transparent will affect the display cost quite a bit. What you can try instead, is changing the size of the mesh. So, instead of making the sail transparent, you change the size to the smallest it can be, and maybe move it, if needed.

[Kwakkelde Kwak]

I remember your thread or posts about that issue with the raygun or whatwasit... As I understand it LL is about to release a viewer where invisible faces aren't rendered. Common sense tells me that means the display weight issue should be solved aswell then. (This ofcourse has got nothing to do with the particular thing you noticed, where a single triangle made invisible quadrupled the display cost..or doubled..I forgot. That is just nonsense:)..or put more mildly, a flaw in the system, they can't monitor every face and its properties ofcourse, that would kill SL )

[Drongle McMahon]

"will return to the default H and V pattern of 1 and 1"

Oh yes. I hate that one. Ruinous for large waterfalls. Fortunately you can get around it with mesh by using the UV map to get the repeats, stacking or making the map larger than the image. However, the repeats are then not adjustable, so it's only a partial solution.

[Toysoldier Thor]

Sadly that is what i make and sell.... large waterfalls, long stretched sculpty rivers etc.  and again - until the day that a mesh is not costly to the sim for being made very large on the sim, sculpty is still the best option for my customers.  This is specially the case when a script is need to animate the texture and we all know the nice added penalty LL placed on mesh objects with a script in it.... something a sculpty is not penalized for.  Of course for an animate - the script could be removed after the texture is animated soo this mesh penalty can be retracted.

As for mesh UVs... i am still struggling to understand anything more than the basics of manipulating UVs for a mesh to do special tricks. 

For this specific problem and if I were to make a mesh waterfall or river I guess I could bake one large raging river water texture across the entire river or waterfall mesh that looks good painted over the entire surface BUT i dont think you can animate a mesh that was brought into SL with its baked texture during import.  Even if a script could animate this baked texture it still would not work because the baked texture would not be seamless.  So as the texture slides across the mesh surface, the seams at the initial edge would be seen.

As for anything more complicated about using UVs to make more than one surface on a mesh.... I have asked in another thread and no one yet knows how to get Zbrush to create multiple texture surfaces on a model.  I suspect its somehow done by creating a UV island on the model for each surface desired.... but that process in Zbrush is still a mystery to me.

There is a workaround solution to the texture animation bug for prims / sculpties - a special script that must stay on the sculpty to keep it aligned with the set H & V Repeats.  Of course this adds more load and lag to a sim but its my only option for my customers since LL refuses to fix this bug after 4 years.

LL would rather we add more lag into our prims than for them to take a little time and fix this bug once and for all.

[Kwakkelde Kwak]

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Toysoldier Thor wrote:

This is specially the case when a script is need to animate the texture and we all know the nice added penalty LL placed on mesh objects with a script in it.... something a sculpty is not penalized for.

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The script will make the server weight of the mesh 1.0 in most cases, that means the LI of that mesh won't be higher because of the script. If you had two meshes linked and the total LI was 1, then added a script, you'd have a LI of 2. The same you would have had if you linked two sculpts together.

 

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Even if a script could animate this baked texture it still would not work because the baked texture would not be seamless.  So as the texture slides across the mesh surface, the seams at the initial edge would be seen.

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It's not mandatory to bake your textures for a mesh object, just like it's not for a sculpt. You'll have to make sure the UV map is ready for a seamless texture, but that's not that hard to do.

 

Btw, a very nasty bug which destroy a lot of nice fountains. Somehow this seems to be a water issue:)

[Toysoldier Thor]

When I get comfortable enough to fully understand how Zbrush UV mapping works beyond how UVMaster does its magic I will hopefully figure out how to perfect  the process / technique UV mapping for animated seamless textures - like water and lava.

I havent tried animating a seamless texture on one of the 5 mesh models I have created in SL.  I could try it.  But sounds lyou you are saying that unlike how a seamless texture flows across a prim or sculpty (i.e. seamlessly), this will not be the case with a mesh.

Since my most common model shape for making landscape terrains sculpties has been PLANE type models, I have been practicing the creation of 3D Plane type models for import to mesh.  There are a few gotchya's with plane type models but so far nothing too bad.  but I am only using mesh models for art statues right now - not landscape terrains.  Maybe I will quickly try creating a basic one to see how an animated seamless texture flows over a PLANE type mesh that is not too deformed.  It will just be a single UV island model (since I dont yet know how to tell Zbrush to create islands).

And thanks for the sympathy on this 4 year old JIRA.  Last year I made an all out effort - right to Rodvik - to get this Jira looked at.  I did end up getting Oz Linden to actually tease us and pretend that he was actually going to get this fixed but as you can see from the Jira comments.... OZ and the rest of the LL Staff slithered away quietly from this joke of a Jira.

I am not sure why LL is so scared to fix this jira.

 

[whyroc Slade]

I've noticed some strange behavior with textured meshes, an issue I had ended up being actually the texture I was using.(I had exported a .png) when I re-uploaded the .tga copy it was much better on the object in SL. also make sure there is only a single uv layout for the mesh.

 

-w