Land impact?

[Spinell]

Hi there.

I've been working on this short cloack that rests over the shoulders and I finally got  it looking right. It has around 650 something vertices but for the cloak to appear properly in SL I have to apply the solidify modifier.

Now the reason I hate solidify is that for some reason, when you apply it, you get something like double the versices you started with. And I wasn't planning on using this modifier when I started building the cloack, so I didn't account for that.

When I went to do a test upload on the testing grid, the cloak had 6000+ land impact. I was told from a help group  I'm in that if the mesh is over 3000 something land impact, just scratch the project and start over because it's way too much impact for clothing items (I make clothes).

It took me around a week and 2 new projects to fix all the problems with this cloack, so I really didn't want to scrap it. I've been very confused as to what land impact really means; I know it's not a direct "number of prims simulated" converstion, but it seems that everything, EVERYTHING I build always has more than 3000+ land impact.

In otehr words, I could say that I still don't know how to build Mesh for SL, not because I lack modeling knowladge or anything like that, but because I can't build stuff "compatible" with SL in the way of land impact.

 

Now, some more details about how I built the cloak (using blender 2.63):

I was told to always build things from very simple, primitive mesh shapes. So, I took a simple plane, subdivided once (I think the number of cuts was eitehr below 10 or was indeed 10, can't remember) and then did a cloth simulation of it over the shoulders of the SL avatar. When I got a cloth shape I liked, I applied it and started working on fine-tuning the details. Never did I add more vertices.

 

I really need someone to teach me how to properly build things for SL so that the land impact stays below the 3000 mark. I haven't been able to find any guides or tutorials about this anywhere on the internet, so I'm turning to the forums.

[Dilbert Dilweg]

Hmm that sure is a huge land impact. You might change the object properties from convex hull to Prim and see if that greatly reduces the impact...

If not. Look into using Meshlab It can reduce your poly count a great deal without destroying the quality of your model

 

Also I have heard some will make a direct copy (shift-d) of the model and flip the normals to make an opposite side of your model

[Spinell]

How do I change the convex hull to prim? And what does it do?

[Kwakkelde Kwak]

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Spinell wrote:

How do I change the convex hull to prim? And what does it do?

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You can do that in the edit menu after uploading, as long as you made a seperate physical shape, which is not neccecary for clothes since they don't have any physical properties when worn.

It would help if you could say what causes the high landimpact. Edit the object inworld or look after calculating in the uploader and post what number is so high. 650 verts shouldn't be an issue, as long as you don't use it for all LoDs. It could be a scaling issue aswell. It could be many things, but I doubt it's the way you built the model. 650 verts or even double that can easily result of a landimpact under 100, possibly even under 10.

[Spinell]

Ok, I took screenshots: the first one is the one which has the solidify modifier applied. The second one does not:

 

If I rezz the object on the ground, it's actually really big, but I have no idea why that is, since I used the avatar workbench to model the mesh to the avatar's size.

Hope you can give me a hand. If you need more info from me, just tell me.

[Kwakkelde Kwak]

Everything is perfectly fine it seems. You'll need some blender user to figure out why your model is too big, it's a common issue. According to the screenshots you posted the landimpact shouldn't be higher than 13 when you rezz it on the ground.

In the upload options you can set the scale of your object, the uploader will directly tell you the size it will be in SL. Scale affects both physics weight and download weight. The bigger your mesh, the higher your download weight. Very small meshes can have very high physics weights.

So once uploaded, does your object have a LI of 3000 when big, as you uploaded it, or when scaled back to normal proportions?

[Spinell]

I am very very confused...

Ok, scaling down the object in the uploader menu helped quite a lot. From the original 12k+ LI I managed to reduce it to 4360, which is a great improvement.

So I uploaded it and rezzed it on the ground (it's very tiny now, but no problems when I "wear" it) and then I edited it and looked at what the land impact was. It said 3. 0.0

Land impact of 3?! How?! The uploader said 4360!

Is the uploader lying? What's going on?

[Dilbert Dilweg]

You have to use blender in a scale that Sl recognizes. I am not sure what blender version you are using . but you can set the scale to metric or NONE on the scene panel ... 1 blender unit to equal 1 meter. after you have set the scale. In Object mode you should be able to hit alt-a to apply scale. try to get in the habbit of applying scale

If you rez the item and it is huge. just scale it down to the size you want. . Some cases large scaled objects in world will increase the land impact. but should not increase it that much

when you rez it on the ground. right click the object and edit, then go to the object tab and change object type from convex hull to Prim.. some cases leaving it was convex hull it increases the land impact. mostly when linked mesh is involved

I have a hat that has more verticies than your cloak and only has a land impact of 5 and I used the solidify modifier

Also look into removing doubles. Depending on how much modeling you have done you may have ended up with a lot of double verticies... thats a simp[le click on one button with the cloack highlighted in edit mode

 

[Kwakkelde Kwak]

The uploader gives you the number for landimpact with 3 decimals, the english/american way with a dot not a comma.

So what you see in the uploader is not 4360, it's 4.360 (or 4,360). Coudl the solution to your issue be that simple? I guess:)

 

Anyway, the landimpact is a pretty useless number for worn objects, since the physics do not count and the LoDs change differently from rezzed items. Furthermore, if anyone tells you clothes with a landimpact around 3000 are fine, they need to get their head checked. As you noticed yourself a couple of prims worth of mesh is plenty.

[Spinell]

OOHHHH.... So it's a english/american thing. I didn't know. So it's telling me the land impact is 4 not 4k. Got it.

That might have been the problem, since I was the one telling people it was 4k LI. No wonder they flipped.

Thanks for clearing that up for me. A very simple reasing problem but I was getting desperate in figuring out how I could reduce the number of vertices.

 

I'll work around the scale inside blender, it might be something worth getting used to like you said.

Thank you very much for all the help, guys! This land impact thing was certainly confusing!

[Dilbert Dilweg]

yes thats decimal point. not a comma

After you upload it and rez it, you can right click edit and look at the land impact number and it will be a true number without decimals