Problem with dimensions after upload

[Suki Hirano]

I have this simple hook created in blender, you can see its dimensions in the screenshot:



The dimensions are nowhere near the SL limits of 0.01/64. Next I try to upload the model (in test grid):



Looks fine in the previewer window. This is after uploading:



The dimensions are completely messed up, and one of the dimensions turns to the limit 0.01 for some reason. You'll also notice that the model itself is messed up too, with the Z axis wayyy stretched (despite being shrunk to 0.01).

Anyone know what's going on here?

[Aquila Kytori]

Hi

 

First thing to try is before exporting Apply the Scale so that the X, Y and Z in the scale panel all equal to 1.



[Suki Hirano]

Thanks, but unfortunately applying the scale didn't have any effect, the dimensions after uploading are still 0.028/0.018/0.01 and the Z axis is still stretched.

[Aquila Kytori]

The reason it is stretched is for some reason when uploading to SL the uploader is reading the Z dimension as less than 0.01 meter 

Probably best if you could upload the .blend file of your little hook to  :  http://www.pasteall.org/blend/   then paste the download url here so that I or someone else could take a look at it. 

 

[arton Rotaru]

I have a question, if I may ask? Why does it have 5564 triangles?

[Suki Hirano]

Here is the .blend: http://www.pasteall.org/blend/38461

Note that in order to bypass the 0.01 limit, I added an extra invisible vertice close to the hook to enlarge the bounding box. The same thing worked for some other models I was working on (no problem after imported), but just has problems on this hook.

Yes I noticed in the uploader, beside "scale", it says dimensions after upload will be 0.028/0.018/0.01.

 

[arton Rotaru]

Having just a single vertex is not enough. If you delete the stray vertex and apply Scale & Rotation, you'll notice that the Z dimension is just 0.004. That's what SL will read obviously, hence it stretches it to 0.01.

It should be at least a single triangle to make it larger. When you snap 2 vertices of the triangle together, without merging them, you will have just an invisible line. If this line is going across the bounding box of a cube, with the cube centered on your hook, you get a perfect square bounding box in-world too.

[Suki Hirano]

Is it possible to make the geometry centre at the centre of the hook? The moment I add an edge or face instead of a vertex, the centre (ie the directional arrows in SL) would get moved to the gap between the hook and the invisible edge/face. Yes I've already moved object centre to the centre of geometry or centre of mass in blender, and it actually looks fine in blender (directional arrows are at centre of hook), but after uploading to SL it doesn't appear that way.

Also, I've seen tons of mesh in SL that are able to have tiny sizes without adding an extra face (ie when I right click it, I see no extra parts). I'm pretty sure they were able to do this by just adding a vertex since the vertex is completely invisible and won't get highlighted even if you right click it. My other models were able to expand their bounding box with just a single extra vertex, any reason why this hook doesn't work?

[arton Rotaru]

Stretching the dimensions with just a single vertex does work, but obviously not reliable. However, you can snap all 3 verts of a triangle together, to eliminate the edge while selected. But you won't have the bounding box centered this way.

Why do you put such an insane amount of geometry into a such a simple object, which is so small that it can be barely seen in-world anyway?

[Aquila Kytori]

This is what Arton meant :



The long edge of the triangle passes through the origin of the hook mesh.

Next one of the vertices of that triangle will be moved to the same position as the highest vertice of the triangle.

The triangle still exists, but looks like a single edge passing through the origin. This edge/triangle will not be seen when the

hook is rezzed inworld.

 

[Drongle McMahon]

There may be a clue in BUG-8987 to the reason single extra vertices sometimes work and sometimes don't. Normally, only vertices referenced in triangles are considered by the uploader, but if it's the first vertex in the vertex position list, then an unreferenced vertex can affect the bounding box.

It's interesting and useful that Arton's collapsed triangle works. The uploader does contain code to reject "degenerate" triangles - those with no area. Each time a vertex used in a triangle is added to the geometry, it is tested against the limits of the bounding box. If it lies outside it, the box is extended to include it. So I guess that must be done with the degenerate triangles too, before they are detected and eliminated.