Vlad Soleil

Hello, A large chunk of prims were returned to my Inventory Lost and found saying the parcel is full, which was not true. Some of my neighbors have similar problems. The Sim in question is "Morgause" and the restart didn't fix the issue (only few prims were "recovered") Could you please help us? Thank you.

... and I decided to stop working with Sculpted Prims just because I thought it was too difficult to predict their LOD behaviour :matte-motes-big-grin-squint: However, thank you Kwakkelde Kwak and thank you Drongle McMahon for your help in classifying this as a bug.

Now I'm able to reproduce the issue even with a single box, with 3 materials applied on it (same material on opposite faces, I've not tried different combinations). When I rez the object inworld, it is 0.1x0.1x0.1 meters. Then I create 3 new boxes (inworld, with a copy & resize from the original one): a) 1x0.1x0.1 meters b) 0.1x1x0.1 meters c) 0.1x0.1x1 meters What happens is that the box c (made from a resize on the Z axis) has the same behaviour as the original box and collapse before the other ones (even setting the size to 0.1x0.1x10 meters !) No, the concept of “bounding box” is not enough to explain this and for sure there is something strange...

The problem seems to be related to the number of materials in the model. The original model had 4 materials and now, after removing them, the object shows a completely different (and more conventional) LOD transition behaviour.

Thank you for the info. That thread about your model was really interesting. However, the pivot of my object in 3DSMax is aligned with the scene. I've checked the transformation matrices for the collada models, and they are: <matrix sid="matrix">1.000000 0.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 1.000000</matrix> so, for what I understand, there is nothing strange in them (coordinates are kept unchanged). In your previous thread you wrote that “it could be very possible the uploader counts x and y far heavier than z for LOD”, which is *exactly* what I think now.

Whatever the bounding box is, if you double the Y size or the Z size, you should double the bounding box. The original problem I noticed was that (on the red object) “if you double the Y size of the object you increase the Lowest LOD transition distance more than if you multiply the Z size by 50, and you get less Land Impact penalisation.”. Honestly, I can't believe to a such level of oddities in a DAE file for an object made of only 44 vertices. The llGetScale() function for the mesh returns correct values, so SL sees the correct measures in that DAE file.

Yes, the blue one could be ok... but my problem is that I can't (and I don't want to) repeat all these tests for each mesh I upload, just to find the right way to get the best LOD behaviour. The LOD behaviour should be the one described in the official documentation, and should depends only on “the radius of the object's bounding box ®”. If something else can affect that behaviour, as my tests seems to indicate, I think it should be documented as well.

I don't think it is fixed :matte-motes-smile: That object is made of only 44 vertices and it shows an “odd” behaviour... what will happen with objects made with thousands of vertices !? If it is not a bug (and I have no reason to think differently), I'd like to know what I'm doing wrong. I've simply rotated the objects in 3DSMax, resetted the transform matrix and then exported it.

Thank you for your answer, Kwakkelde Kwak. I've tried to rotate inside 3DSMax an object, and the attached picture shows my results. The red object is 0.1x0.5x1.0 meters. The blue object, which is the rotated red object, is 0.1x1.0x0.5 meters. The yellow object, which is the resized red object, is 0.1x0.5x10.0 meters. I've uploaded the red and the blue objects with the same High, Medium and Low models and I've set the Lowest model to 0 triangles. This time I'm using the Phoenix Viewer and, as you can see, the red and the yellow objects collapse to the Lowest LOD before the blue object!

Hello, I'm observing a strange behaviour on how the LOD levels are displayed. I'm using the official viewer and I've uploaded a different collada model for each LOD level, but it seems that the Lowest LOD model for two objects sized (XxYxZ) 1x1x1 meters and 1x1x50 meters is displayed more or less at the same distance, which is less than the distance at which the same Lowest LOD model is displayed for an object 1x2x1 meters. In addition, the Land Impact of the 1x1x50 meters object is higher than the Land Impact of the others. So, if you double the Y size of the object you increase the Lowest LOD transition distance more than if you multiply the Z size by 50, and you get less Land Impact penalisation. According to official documentation “To compute the distance at which each LOD is displayed, take the radius of the object's bounding box (R) and divide by the LOD ratios used in the viewer”. Should I therefore conclude that the “radius of the object's bounding box (R)” is the “radius of the XY projection of the object”?. Maybe the behaviour is correct with regard to the documentation, but from a practical point of view it does not seem acceptable. Has anyone had the same problem? Thank you. Best Regards, Vlad Soleil