Kwakkelde Kwak

I have had a similair issue yes, not sure if it's the exact same thing though. In my case it had to do with rotation. A 0.5x4x24 m (I think, but something like that) object switched LOD at less than the objects length, around 10 meters. Turned out the pivot was rotated by 90 degrees before uploading. I hope this helps. Weird thing was the object showed fine in the upload window, yet when rezzed it defaulted at a 90 degree rotation. If everything works well, the bounding box is measured using all 3 axes.

LindaB Helendale wrote: My comment on the triangulation of faces with more than 3 vertices was about how the SL uploader triangulates polylists. Yes I got that:) ... looks like creating triangles is preferred then, before exporting to dae. It probably won't give better results, but it makes life a bit easier for the uploader, since it doesn't have to process as much data. I think there was some (cough) confusion about triangulating, when in the process and why to begin with. Lots of things to consider, the one you described was certainly one I didn't think of. You should be able to set the material IDs (which are apparantly grouped in a dae file) without adding an actual material. Just use different channels for the different faces. No idea how it's done in Blender, but I'm sure it's possible. I've never had any real issues with smoothing or grouping or order of materials and I never looked inside a dae to make that happen. (I have for other issues)

Yes now that you mention it I have that same option in the collada exporter. Still I'd be surprised if the result was different. (However it won't hurt to tick the box.) This is not the same as triangulating the object yourself to see if you need to change geometry...

I know I mix up 3D software and mathematical lingo, well I use them both, but try to keep them apart really... but as far as rendering goes I only talk SL:) Otherwise we would get even more confusion...nurbs and all the other non polygonal...eh non triangular methods.

I missed the comment indeed, not the fact the two right columns are the same. One would think the Blender data is converted into collada data is converted into SL data, keeping the triangulation the same way. I do not think Blender "thinks" it's a quad, it just doesn't show the diagonal. I would be very surprised if that quad looked different in SL. Then again, today seems to be the perfect day for that since it's kwak confusion day it seems. Hmm....someone said something about "polygons" in the DAE....if the DAE stores quads, it SHOULD be possible SL does the triangulation differently....never looked in a DAE file really... Still my guess is the triangulation is the same, makes sense to me the vertex with the lowest number is where all the triangles meet, or originate from...

Getting fun? I got the impression I was annoying half the forum users, but I'm glad to hear this... Not sure what you are trying to say with the picture, but the quad in the top left corner should be added to Chosens diagram, that was all I ment. Furtermore, the one on the top right is an impossible one for rendering. I know it can show on your screen like that in a 3D program..well untill you move a vert, then you will (even without a visible line) see you are most definately dealing with two triangles.

merge duplicate verts with shared normals that is..hehe

Um yes so that means the uploader does a fine job then:) And YES I despise the term polygon aswell, it's way too confusing... a tri and quad are generally accepted as "building blocks" (yes again confusing), anything over I see as multiple tris or quads...

Jenni Darkwatch wrote: Btw, a little testing did actually confirm what others have posted here... letting the uploader auto-generate triangles from ngons is just bad. I've uploaded a rectangular ngon, and the uploader did triangulate it so that the triangles were connected like this: The top "triangles" were essentially a two-dimensional line. Again, based on old knowledge that's not a good thing and a good argument for doing the triangulation or at least quadrangulation by hand before uploading. Of course, things have changed so much that it might just as well be irrelevant with modern GPUs Edited to add: I realized I made one connection too many in that graphic... sorry. Basic principle remains though. I've uploaded plenty of quads onto the grid and never have I had any results you describe. It might be a bug in either the model you built, the exporter you use or the SL importer combined with any of these two. There seems to be something fundamentally wrong with the picture you show. It should have 5 triangles or it can't exist, unless the line is doubled with one line between the outer vertices, but that should be impossible aswell. As far as I've read, two dimensional objects are not recognised by the uploader. (never checked this, but it makes sense) Either way ofcourse it's good to check the triangulated model before uploading, but in a lot of cases it will simply be wasted work. It depends on the model ofcourse, so if you aren't sure when it's needed, better have a look at all your work. I am very confused today...quadrangulation by hand? EDIT..forgot about the smooth/normal.... I prefer setting smooth and hard edges by hand rather than by uploader...but I get the "normal map" you mentioned. When I think of a normal map I think of something else...I probably shouldn't:)

Gaia Clary wrote: I always thought that the definition of polygon does not require it to be flat . take 4 vertices and connect them by edges. As long as the edges define a closed path, the polygon is a quad. independent of whether the vertices lay in one plane or not. Looks like both you and I are not done learning then:) As soon as you pull one vertice out of the flat plane you create a new edge, then the shape can't possibly be a polygon. Ofcourse a 3D program will still tell you it's a polygon, but for that program the polygon wasn't a polygon in the first place, but a set of triangles. (which are ofcourse polygons on their own..) In other words, in polymodelling or meshmodelling the only true polygon you use is a triangle. Gaia Clary wrote: I think the goal is to cut all polygons with vertexcount > 3 into an "optimal" set of triangles. I learned that the triangulation in this example is a "fan strip" compared to a "triangle strip" which seems to be the favorised triangluation regarding texturing. I can imagine that fan strips suffer more from texture distrotions than triangle strips. I read about this some time ago but i can no longer find the link to the article. Wikipedia has something about "fan strips" and "triangle strips" .... There should be no texture distortion at all with either setup, since we have UV mapping. Both objects are flat, so is the texture. Still I do not see a difference between a quad with a vertice added to the center and any other polygon with the same treatment. (you were quoting that).

LindaB Helendale wrote: If it's flat it won't matter much but in general the polygons would not be flat and then those triagulations in the middle row of Chosen Few's pic produce triangles with less sharp angles (and shorter crease egdes) can give flatter patch and more natural looking reflections. That's why those triangulations are commonly used. If they are not flat we're not talking about polygons... or are you talking about multiple flat polygons like this resulting in a curved surface? LindaB Helendale wrote: Yes of course the result depends on the direction the triangulation is done but for quads the only way to do it is to split between two opposing vertices, so unless you specifically need it done in the other direction (from vertex 1 to 3, not from 0 to 2) the SL uploader does it the same way as any other tools. I definitely agree that doing it yourself gives better control than letting the SL mesh uploader do it. I really don't see the difference between the quad and the other polygons. If you follow the same logic you and Chosen did for the pentagon and hexagon, you could add a vertice in the center of a quad aswell.

Jenni Darkwatch wrote: For all intents and purposes the SL shader seems to ignore triangle orientation _if_ the surface is normal mapped. If not, your distinction is of course correct, though in that case I'd thing the edge is intentionally placed by the person modeling it. Normal mapped? in SL? I'm getting a bit dizzy... And ignoring triangle orientation? that really would surprise me. Are you saying SL treats both quads I drew the same as far as shade and light go?

Where did that smother animation appear? I must have missed it

Chosen Few wrote: That's how any renderer sees it. Are there really renderers that convert polygons the way they are drawn on the far right? I can see how a shape like that is useful in some cases, but it's no longer a polygon by definition. It's a flat pyramid.

Ah, that 5 day cap explains the changing address then... but as you and whowasitaboveyou in the thread say..it is possible to send IMs:)

I haven't looked into it, but you can definately send an email to an avatar. I think it's done by replying to an IM that went to your mailbox. Not sure what the exact adress for any avatar is, but it ends with @im.agni.lindenlab.com and it's always the same for any avatar. EDIT... Not always the same, still you can reply to these mails... I'm not really interested in it, but anyone who is, might want to play around with it.

LindaB Helendale wrote: SL mesh uploader triangulates the polygons (specified by <polylist> block) by drawing edges from the first vertex in the list to all other vertices, which is not so good way to do it. A hexagon is triangulated like this Ok, educate me here. The behaviour of lighting on this hexagon would be different from one where the lower triangles would be mirrored horizontally, but I really don't see why this is "not so good". When it's flat I see no disadvantage at all to be honest. LindaB Helendale wrote: Quads are done the same way, so for quads you could let the mesh uploader do it, but not for any polygon with more than four vertices. This is just not true. As both Chosen and I said earlier, the way light hits a quad when bent, is affected by the orientation of the triangles within it. Two quads with the same vertice pulled up, as you can see they are nothing alike.

Although Chosen gave a very extensive and complete explanation, I'd like to add one more thing in favour of the quad over the triangle. Since light in SL usually hits objects from above, horizontal edges will give you smoother shadows than fractal ones that are the result of triangles.

For convenience purposes, as has been said by the others, working in quads has some advantages. As far as SL or any other renderer is concerned you can work in triangles, quads, pentagons, hexagons, etc... You mentioned the term already: tessellation. Before your model is rendered everything is tessellated into triangles. So a quad becomes two triangles, a pentagon becomes three triangles, a hexagon becomes four triangles etc. The advantage of working in triangles (completely or partially), especially when working with complex objects with lots of curves and different sections, is you have better control over the uniformity of the polys. It's one of the big advantages of mesh over sculpts. A sculpt sphere for example (or the basic SL sphere) has very small polygons near the top and bottom, a lot smaller than you need for the detail you want. Using only quads there's no way around this so you use a lot more resources than is neccecary. With triangles you can keep every face the same size. EDIT There's usually no need to turn your quads into triangles before uploading. The SL uploader will do the exact same thing. It will only matter if you have some curved planes where you need control over the way the two triangles make up the quad and in most builds this won't be the case. The sphere on the left has 360 faces, the one on the right has 320 faces.The one on the right has more curve and more uniform curve.

Chosen Few wrote: @Kwak: It would appear the wording in the wiki is wrong. (Not the first time.) It definitely works per pixel, not per object. I've edited the wiki to correct it. Of course, the whole thing is out of date anyway, since it still lists it as being under the Advanced menu instead of the Develop menu. Correcting that is more than I care to tackle right now. Hence the "maybe".. I thought it didn't make sense..anyway glad you fixed that...

That looks like flipped normals. I'm not a Blender user, but my guess is Blender has "double sides faces". SL, and about any realtime rendering program, shows only one side of a face.

Never used the tool, but according to the wiki it should show the RGB colours. It does however say this: > Show Color Under Cursor - Show the RGB color values of the object the cursor is on. It mentions object, not pixel, maybe that's a pointer.

Glad you found the log, looks like the file you need. However posting a 6 MB textfile isn't very inviting to take a look at. As you might have noticed, the entire log is timed. So what you need to do is force the error then look in your log and see what it said for that moment. If you post that, I'd be happy to take a look, as will others I'm sure. And there really is no reason to have 12k faces at a lowest LOD...glad you say you are going to make some custom LODs. A highly detailed logo on the inside of a gag is really silly if you ask me, no matter what LOD. I don't really go by Chosen's standards concerning polycount, since SL is not a game that needs very high framerates opposed to a shooter or racegame or whatever action game. However Chosen's numbers make more sense to me than yours, a lot more. Even if you say you need so and so many faces to make smooth shapes, ask yourself what I said earlier... how many faces go in one pixel at a certain distance? if that's more than one it's generally too much. Don't use this as a rule, but as a guide... Higest LOD can be really detailed and smooth, since it won't show often and not for many people, but you also want smooth transitions between the LODs.... Takes some figuring out, but that's well worth it.

When I upload a physical dae (which I do more or less always in a final mesh, not when testing) I don't change any settings. I just pick the file and it seems to work. The only thing that sets the physics DAE apart from the other models is that it is a) not visible and b) it is always there, no matter what distance you are looking from. There most definately is a relation between the dae and the physical aspects/behaviour of the column. In fact it is what determines it. It is the shape SL uses for collisions (with other objects and with avatars).

My experience is you need at least a 2 degree difference from the base pose. Since the rotations in that base pose are not exactly 0 degrees (to my best knowledge), I usually go with a 3 degree minimum.