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BadEddy

Mesh land impact

21 posts in this topic

I got a mesh made for me. What was delivered is a .dae file I can then upload to SL. So far so good, the mesh look awesome. 

Now the prim: my only disappointment. While I see some very complicated mesh items can sometimes take only 1 land impact, this one is 77. I'm sorry but 77 prims is not very acceptable for a very simple item. 

So could anyone help me figure how I could help this land impact problem? Is there anyway I can reduce it? 

 

Thank you

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As I understand it you have the dae file and have to upload it all by yourself

You have quite a few options to reduce land impact in the upload process

See Uploading a mesh model in the knowledge base

:smileysurprised::):smileyvery-happy:

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If you got only 1 dae file, a way to reduce the LI is take it into Blender and build the lower LoD files.

You can try making it phantom. If the cost is from a high physics cost, that can help.

There is also a matter of scaling. Since you didn;t say if it is large or small, I don't know whether to say scale up of down.

The LI Cost algorithm is complex as a whole and certainly not intiuitive. But, it is not that hard to understand. Numerous small triangles used in the phycis model will drive up cost. Large items with lots of polygons will dive up cost. Lots of polygon will drive up cost.

Look through the Mesh section of the forum. There are loads of posts on how to reduce LI Cost. But, most of the tips are about how to build them so they will be cheap.

I have numerous articles about mesh cost in my blog. Try: Mesh Related.

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As the others already said it depends on many factors.

- the amount of triangles used in the model (if it's has a lot of polygons and could possibly have been made having the
  same look and shape by using quite less)
- Along with the first point comes the LOD levels of the model. When you build them yourself, and when you build very good
  and optimized LODs for your model you can decrease the impact quite a bit.
- The scale / size of the model
- The physics shape that was build for it, or the used offered algorythm to create a physics shape in the uploader.

But as you see it breaks down into several categories. Physics impact, download weight, rendering cost etc.
Thus there could any of these  - or all of them together be the 'troublemaker' here.

If you could provide a bit more information about the model. (Wireframe screenshot out of blender), the amount of tris/faces, its scale etc) That could help to identify what is causing the high landimpact.

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I suppose you're not going to change the model in Blender or any other program, so let's see what can be done without.

If the physics cost is too high, link your uploaded mesh to a box in SL and set the mesh to physics type "none" (edit menu, features tab). It will remove all load on the physics engine, but you can no longer walk into the object.

If the download cost is too high, you can set the numbers in the uploader for triangle limit lower for medium, low and lowest. Depending on the model this could make a small or huge difference, both in looks and in landimpact. You could go as far as setting low and lowest to zero. It really depends on the shape and size if this works.

For a possible next time, make sure you tell the builder your landimpact limit. Also ask for instructions on how to upload the model.

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If it has lots of cyclinders, torus, or spheres shapes in the construction of the mesh, it very well indeed could be 77 prims or higher. You might be able reduce it some if you change it from convex hull to none when linked to another prim.  Is there any sculpts linked to this item?  If so, unlink them and check the LI.  Some of the older sculpted objects and run your LI off the scale.

You could import the .dae file into blender (or another modeling program)  and try to reduce some of the geometry.  If someone created this for you as a custom job, contract them to see if they can proved you with a lower LI cost mesh.  BUT, be aware whne you start reducing the geometry, not only will it impact the LI but how the mesh may look.

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So everyone answered your questions, but I am going to take a little big SIMPLER approach assuming that if you contracted a mesh item, most likely you do not MAKE mesh.

If that assumption is correct, disreguard all references to "make your own LODs".  Blender is a hellish program to learn and I used to make my living doing multimedia Flash so I have some background in tough programs.

SIMPLY as I can -- your best first step is to look at how you are trying to upload. Again I am going to assume that you just let the uploader tell you what to do in the options area.

First -- there is SIZE. If you want your object to be 1 meter by 2 meters say and the default upload size states 10 x 20  --- change the number in the size upload box to reflect a close to correct size.

Second - SERVER cost.  The minimum server cost is .500 (that is for ONE JOINED OBJECT -- think of it as a linked object that you can't take apart). If your item says 10.000 then that means there are 20 pieces in the linkset (you can "unlink" them in world and use the parts individually - theres a more complex answer but let's skip that).  You may NEED or want that for your project. It is unlikely that is the part of your problematic upload equasion though because that would be 154 pieces. :smileysurprised:

Third PHYSICS cost. If that is the high number in the uploader AFTER you have changed the size, then that's a pretty big issue and one you probably can't address on your own (again assuming you don't make mesh).  If it is indeed a simply object and all ONE object then you can use a simple cube DAE file for the physics model. Again, kinda complex so let's hope it is ------

DOWNLOAD  ::::::

This is where a LOT can change easily. The important thing to remember is that you need to TEST these choices to make sure your item will look as you will like it -- not have horrible LOD at 20 meters away for example. So that means the ADITI grid (formerly called "beta grid" ) where you can test for free. You need to do a separate test for the ADITI grid in order to upload mesh.

Uploader.png

Here is a good example of what you might have seen when just using the defaults of the uploader. Way more complex than I usually do.

Note the server cost is .500 (this is ONE mesh object and cannot be unlinked).

Note the physics cost which isn't awful but still too high. I used the "cube" trick to get around that and it worked just fine as physics wasn't all that important. There are BETTER ways, but not if you don't build mesh regularly.

So look at the download number. 51 land impact.  By changing the 3rd and 4th  LOD numbers (and possibly the 2nd I really don't remember), I got a complete build with great LOD holding. I tested extensively before final upload. This is a complex items with lots of parts that you can't see. Book, papers, beakers, etc.

It came in at ONE Land Impact.

Mesh can be daunting, even if you are "just" uploading it. Hope this helped some.

 

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Sounds like whoever made this mesh was not aware it was going to be used in SL. Either that or he doesn't know much about SL.

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Not necessarily. As you can see by my example, they may have made a perfectly good mesh but figured the person buying knew (or should be able to figure out) how to upload. Perhaps not the best plan, but there is really no reason to assume the mesh is faulty since we don't even know what the mesh IS :D.

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Yes I had not read the whole thread and I see your point, ESP about the last two LODs.

 

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I logged onto the test grid to try out some Mesh creations but it wasn't clear where I could go to work is there a dedicated sim somewhere?

 

Confused....

 

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It's a testing grid, so LL owns all the land. As long as you don't stand right on top of someone elses work you should be fine. I usually go to one of the mesh sandboxes. just type "Mesh Sandbox" in the search field of the map, there are several, not always all of them online.

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There is NO reason a 3D Model of a table with some glass bottles on it should ever be 14,000 tris that is stupid as heck. At most it should of been 5K or less. I did an entire mech walking spider that was only 10K as a non-physical vehicle.

Snapshot_003.jpg
I'm sorry but the sl modeling community is the most uninformed group of people I have ever met when it comes to game modeling. They refer to 3D models as mesh, and call it "meshing" not realizing anything in a 3D world is called mesh. (unless its a voxel engine) They really need to watch some serious game modeling tutorials for something like garrys mod or the Unreal engine even. With Normal map support and Specular map support they really REALLY need to catch up with the industry standard if they are going to be playing with a modeling format.


Please watch this video if you are interested in how to make PROPER 3D models.

As for land impact and physical impact make custom LoD's and custom Physics shapes. You can drastically decrease both from that. The land impact calculation algorithm is a tricky one but if you understand how it works it will help out. :)

How Land Impact Is Generated

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I recommend the grid area named Balance its a general vehicle testing sandbox with no linden damage. I use it to test all my stuff before uploading.

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Tomos Halsey wrote:

I'm sorry but the sl modeling community is the most uninformed group of people I have ever met when it comes to game modeling. They refer to 3D models as mesh, and call it "meshing" not realizing anything in a 3D world is called mesh. (unless its a voxel engine) They really need to watch some serious game modeling tutorials for something like garrys mod or the Unreal engine even. With Normal map support and Specular map support they really REALLY need to catch up with the industry standard if they are going to be playing with a modeling format.


In SL you meet all kind of people and it is by no means a 'modeling community'.

A lot of us don't know a SIM from a prim and we just find the 3D building options overwhelming and fantastic

New starters getting a helping hand may become professionals

You can't blame anyone you don't know for being uninformed just because he don't know what you know, but you can share your wisdom

:smileysurprised::):smileyvery-happy:

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Tomos Halsey wrote:

[....]

Please watch this video if you are interested in how to make PROPER 3D models.

[....]

 Thank you. That's a well done series of tutorials.  As you have discovered in your short time in SL, this is not a "community of 3D modelers."  The most distinctive feature of SL is that it is a user-created world.  Most of what you see in world has been created by amateurs, so it doesn't have the polished look or the efficiency of stuff made by professionals.  As a non-professional myself, I see that as a fantastic drawing card, although I realize that it probably frustrates a few professionals.  (It's also responsible for a good share of the lag that we all experience.)  Those of us who are amateur creators have a grid-sized sandbox to learn in, and we have the good fortune to have a small cadre of excellent professionals who share their talents to help us grow.  Working alongside the pros gives us a feeling of accomplishment and involvement in our world that we would never experience in a static "game" world.  Anyway .... thanks for sharing.  :smileywink:

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Yeah thanks for your nice replys I kinda blew up after seeing another piece of modeling content be ineffecient. I grew up as a 3d modeler for game mods far before I came to sl. I learned from game designers and modders so I learned from the start about poly effeciency, normal mapping, specular mapping, detail mappinhg, and paralax mapping. I talked to professionals on polycount forums and cgSociety that worked on major Gearbox and Epic Games titles. After that, I came to sl a little too early because they didnt support 3D Model formats. On my first day I was asking how to upload models and nobody had a clue what I was talking about. So I waited a little and went back to making games with design teams as a freelancer for consoles such as the Xbox and PC. Some of the titles I did were Red Orchestra, Quake 3 Rally, Killing Floor and a few others like Day-Z. I came back to sl and was disgusted with the content I saw so I started puting together a group of 3D modelers that have worked on real game content. This is a tough task considereing most of them just have their own store and dont have time to work or talk in a group. I'm sure you will understand after growing up exposed to professionals and a game modding community why I get so heated on the topic of modeling. When I hear someone say meshing i think of picturing a picture. It just sounds completely wrong D: 

If anyone though has any questions about modeling and approaches/insdustry standards I would be happy to help :)
I work with 3dsMax, zBrush, photoshop, and bodypaint. I do not reccomend blender nor can I help you if you use it, but I will reccomend techniques to approach a model :D Blender is not supported in most game companies because nobody writes code for it in AAA title games nor is it a standard so thats why I don't recommend it. Also it has issues with n-gons and normal lighting, it's mostly tuned for CGI at the current time. However this is coming from someone that has worked with game design teams for about 8 years now and didnt have any room for blender in their workflow(that and blender didnt exist when I started modeling xD), as an ameture in sl I don't see anything wrong with it but please watch your polybudget on models. 



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I have been uploading .dae (aka collada) into SL for a year and this is what I know of it from experience and from picking up tips in the forums and the in-game Builders groups (whose staff mostly specialise in pc's / prim / blender / gimp):

1st method: reduce complexity of original object, using built-in (Blender apparently has this) or bounce the model between eg; BalancerLite (is free and works on mac) and your 3D app (I use Cheetah3D for mac).

2nd method: lower the physics setting (high, low, extra low) for the upload in the SL viwers mesh upload screen. This renders the object in its full glory but without the avatar and the shape interacting as if the shape is solid, only some of it will be solid. This is not recomended for building sections eg; door frames.

3rd method: upload and set it to Convex Hull so it reads as 1 Prim no matter how complicated the shape is. You will need to set it to Phantom otherwise the hull will push avi's away from the object. If you need the object to have physics, Link it to an overlaid Prim which is set to Alpha texture (making it transparent which is not the same as Invisible texture, invisible texture can be still seen from some angles in some viewers because it has a dark patch on it).

4th method: link everything together to reduce Land Impact (does not reduce prim count). There are some restrictions on this (see the Convex Hull link above for a great article by Jeremy Linden detailing everything about this). 

I picked Loki's link up from this thread, it has taught me a lot about LoD Level of Detail: check it out.

 

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Hello, reading your take on loading mesh with the lower LOD and noted in your pic that the Generate Normals was not checked, does this have any effect on the LI of the build? the other question is, what does the Generate Normals do for the build being brought into SL...Thank Ric

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OvaUk2 Gutter wrote:

Hello, reading your take on loading mesh with the lower LOD and noted in your pic that the Generate Normals was not checked, does this have any effect on the LI of the build? the other question is, what does the Generate Normals do for the build being brought into SL...Thank Ric

First, please note that it's a very old thread you restarted here and some of the info may be outdated. It would have been better if you had started a new thread, especially since your question really is a completely different topic.

But since you asked:

The normals determine which way a surfaceor point on a  surface is facing. Flat, or sharp, normals means that the whole surface is facing the same way and you get very sharp and clearly defined angles between surfaces. A good example is the basic prim cube. Smooth normals mean that the normals are "rounded off" towards the edges giving the illusion of smooth curves rather than sharp edges. A good example here is a sculpt which always have smooth normals.

With a mesh you can mix smooth and flat normals any way you like. Usually you want to do that in your 3D editor before uploading since that gives you complete control over them but the uploader does include a very simple function that can adjust normals automatically for you. When you check the "Generate Normals" box, all edges with an angle less than the one specified in the Crease Angle field. Edges with sharper angles will not be modified.

The normals do affect land impact. Usually smooth normals give slightly lower LI than flat ones but I'm not sure if that is true for ones auto-generated by the uploader. Also, there are occasions where flat normals actually give the lowest LI and besides, smooth normals often require more detailed LOD models to look good and that may increase the LI quite a bit.

There's no definite answer really. Except: go to the beta grid, play around with the options and see what happens. It's a good way to gain experience and can be quite interestign and even fun. :)

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