Textures blend (or get mixed) when I link several meshes togethers

[Pierre Ceriano]

Hi and thanks in advance.

I made elements of a bridge (railing, main, pillars and so on). The textures blend when I link the elements togethers. Is there anything I do wrong ? Known issue ?

A complete build is composed of 16 elements that give a foot prims of 15 x 15 meters and 12 land impacts ; in case it helps.

Thank you

Pierre

[Pamela Galli]

I cant think of any time I have seen any textures blend in SL.

 

People usually post pictures to show what they mean. 

[Pierre Ceriano]

I took two pics : before / after. On the pic showing the blend of the textures you see two pillars that have now the texture of the borders. I of course done nothing between the two pics ; textures blend by themselves some minutes later. I unlink and relink the elements again so textures apply right again ; but some minutes later they blend again and each time a random way. Other information : my textures are png files and meshes are physics if it helps. Thank you again for your time !

[Drongle McMahon]

Interesting. Is there anywhere we could inspect the vbridge in it's two states, linked and unlinked? On Aditi, maybe? I'm not sure what the separated pieces are, but my only wild guess is that the affected pillars are accidentally duplicated in the geometry, with one of the duplicates having incorrect UV mappping. Then for some reason, the one that's visible switches when the linkset receives some sort of delayed update.

[Pierre Ceriano]

The location the build can be seen.

@ Drongle : do you mean the shapes I used as physics while importing the meshes would influence the dispatch of the textures ?

@ Everyone : I imported textures as JPEG files and it does the same. I also made a convex hull replica to see what hapens

[Drongle McMahon]

No. I don't think it's likely to have anything to do with physics shapes.

[Pierre Ceriano]

For the moment, the textures don't blend on the convex hull replica. But of course you cannot walk on the bridge

Can't find a similar thread about the influence of the features choice on the textures dispatch. I seek now for an exorcist.

EDIT : textures blend on the convex hull replica too ! The region is restarted and nothing changed

[Drongle McMahon]

Where is it?

[Pierre Ceriano]

Where is what ?

The build can be seen there. Thank you

[Pamela Galli]

I cant tell from the pictures, but if you are seeing the textures as overlaid, then I agree with Drongle, it is likely duplicate geometry.  The interesting with mesh is that you do not always get the flickering with overlaid textures that you do with non mesh, so it does look blended, altho it is not.

[Drongle McMahon]

I had a look, and I think this is the problem...

Because they are all linksets, the LOD (level-of-detail) switches independently for each part, and nearer than they would for the wholw thing in one mes, because they are smaller. Now, your medium LOD model has a UV map that doesn't correspond to the high LOD one. The result is that the texturing is from a different part of the texture when the LOD switches. I am guessing that you just happened to be at the appropriate distances when you saw the texture change because of the LOD switch. If that's right, you are going to have to redo the UV map of the medium (and lower) LOD, so that the corresponding surfaces recieve the same textures as at the high LOD. 

In more general terms, this object would almost certainly be better as a single mesh (or at least as larger parts) so that the LOD switches at the same distance for the whole thing. This will push up the download weight, but at the moment the server weight is the highest (8, =0.5/mesh), and joining the meshes will reduce that. Go for a very simple low LOD mesh for the whole joined thing to keep the LI down.

 

[Pierre Ceriano]

Thanks to you Drongle I think I begin to understand something. And yes I think the pb is due to the physics shapes. Some weeks ago i had made the same elements, only convex, adding invisible prims to make it walkable. And it was working fine, no more land impact than the physics shapes, once linked.

But of course adding invisible prims is not super, specificaly if I want to sell them as building components. So I made physics shapes and imported them with the following settings :

English is not my native and perhaps I don't understand very well, but according to what you write, I think I have to set the settings to high and not medium. I try this now and tell you. Thank you so much for your help.

[Drongle McMahon]

That picture shows only the part (tab) of yje uploader for the visible meshes - you can make four, each with less detail, that are seen as you get further away (LOD meshes). The button you pointed at with the arrow is just to select which one is shown in the preview. It's nothing to do with the physics.The physics is on the next tab. There, you can select one of the visible meshes for the physics, or you can use a completely new one.

I am not sure what you have done here. Let me try to explain a bit. There are two ways of using a mesh physics shape.

1. You can use the "Physics" tab of the uploader to add a physics shape mesh. If you don't do that, then the uploader will make a physics shape for you. It will always make the one that gets used if you set the type to Convex hull on the features tab. This is a convex hull for the whole mesh, like a shrink-wrap around it. If your model has several meshes, then each one will get its own convex hull shape. It is made from the low LOD (third) mesh on the first tab (the one you show). If you do tell it to use a sifferent mesh on the Physics tab, then it will use the convex hull of that instead. You can tell it to use one of the four LOD meshes from the first tab, or you can give it a new mesh (as you seem to have done. It will also make another physics shape that you can select by setting the type to "Prim". The other settings on the physics tab control how it does that. If you have multiple mesh onjects in your model, and supply a new physics mesh, then there should be exactly one object in the physics mesh for each object in the visible mesh, and they have to be in the same order. That can cause difficult problems. These kinds of physics shapes are all part of the uploaded visible mesh.

2. (I think this may be what are trying to do) You can upload a model without using the physics tab at all, so that it just has the default "Convex hull" shape (or shapes if there are multiple ,eshes), then separately upload another mesh for the physics shape. You link the physics mesh to the other mesh(es) with the physics mesh as the root (selected first before linking). Then you set the physics shape type of the other, visible meshes to "None" and the physics mesh shape to "Prim", and make the physics mesh invisible ("default transparent" texture). "None" is like using "Phantom" prims with an invsible physics prim, except that the pieces can all remain linked, and it is much better for performance of the physics engine which just ignores the "None" parts. Since the physics is now not part of the mesh, there is no problem associating the parts of multiple-mesh models, nor with fitting the physics shape to the bounding box. So if you do use multiple linked parts, this approach may be easier.

If it's true that you are using mthod 2, then your physics mesh should be invisible. So it's UV mapping wouldn't matter at all. Could it be that you were trying to do this, but you put the new mesh in the "Medium" slot as you show in the picture? If you have multiple objects for the visible mesh, but only one in the physics mesh, then you can't use the physics tab to make it part of the model. It will get associated with just one of the visible meshes and it will be squashed to fit it. So in that case you can only use the second approach - completely separate upload (unless you do some horribly complicated stuff).

(Now we just need someone :matte-motes-wink: to make a picture that will make this easy to understand:matte-motes-smile:)

 

[Aquila Kytori]

Well this isn't really to illustrate either of your suggestions drongle

(keeping it simple)

It is just to show where to upload the Physics mesh if the bridge was a single object :

@ Pierre

If you really need to make your bridge as seperate mesh Objects its probably easiest to upload each part seperately along with its own physics mesh . The Mesh object is uploaded in the Level Of Detail tab and its Physics shape mesh is uploaded in the Physics tab of the mesh Uploader.

[Rosie Dimanovic]

Si le problème persiste même en rectifiant la physic, j'ai une autre solution à proposer. J'ai déjà rencontré ce problème. Si chaque objet ont été créé séparément et qu'un matérial a été ajouté; et si chaque objet on été ensuite joint, alors il y aura ce problème de texture qui ne se place pas correctement. Je te propose de nettoyer ton mesh final en retirant tous les material. Puis recréer tes material. Il faut savoir que le premier material que tu appliques s'assigne automatiquement à l'ensemble de ton mesh. C'est un peu comme si, il prenait en compte l'ensemble des données de ton mesh. Et c'est seulement après le premier material appliqué que tu vas créer les autres material. Donc, si tu as créé un material pour chaque mesh bien distinct, quand tu joints (ctrl+j) et bien dans sl, il ne sait plus reconnaitre quel est le material initial. Ca arrive aussi quand on duplique avec des material déjà créé, il faut faire très attention à ne pas dupliquer en object mode, mais le faire en edit mode. J'espère que cette solution apportera une solution à ton problème.

 

If the problem persists even correcting physic , I have another solution to propose. I have encountered this problem . If each object were created separately and a Material was added , and if each object we were then joined , then there will be the problem of texture that does not fit properly . I suggest you clean your final mesh removing any material . Then recreate your material . You should know that the first material that you apply automatically assigns all of your mesh. It's almost as if it took into account all the details of your mesh. And it is only after the first material applied you 'll create other material . So if you created a material for each distinct mesh, when you joined (ctrl + j) and well in sl , he does not know recognize what is the initial material . It also happens when you duplicate with material already created, it must be very careful not to duplicate in object mode, but do it in edit mode. I hope that this solution will provide a solution to your problem.

[Pierre Ceriano]

First of all, and from the botton of my heart, I would like to thanks all persons who helped me here and inworld :manvery-happy:

So it works now and it sounds - it sounds because i'm not skilled enough to affirm - that it came from :

a - a too simplified medium LOD shape i was uploading

b - under Blender my materials were the same for the diferent elements of the whole bridge

Anyway, whatever the solutions or ideas you brought, I learnt several things I didn't even know the existence ; and it opens new doors for me. Thank you so much again.

Have a good time creating

Pierre