Modeling Parameters to generate a low XML file

[SusanLL]

Hello,

I am a 3D Modeler new to Ogre. I have reviewed some of these threads in hopes to find a general consensus for parameters to build characters with animations. I am looking for a poly count or as some of you programmers would look at it as triangle count.

I am testing the Ogre to Maya Plug-in which we downloaded from Ogre. And I have reviewed the LFA add-on and videos.

Can anyone shed some light on this topic. I have produced a 4600 (give or take) triangle character with a rig and animation of 75 frames.

Problem 1: mesh.XML generated way to large. Programmer wants a 300-400kb file. Not sure how to compress anymore than reducing model even more. (which I am testing now)

Problem 2. In the viewer the animation was very slow. Thoughts on that?

Anyway, If some of you experts could assist in this I truly would appreciate it, as I am trying to streamline our production pipeline for this engine.

-Thanks
Susan

[jacmoe]

I don't really know what I am talking about
(Programmer here)

But maybe the problem is that the animation is too fine-grained?
And thus making the xml file a lot bigger than it would be if the animation was sampled more sparsely.
Just a thought.

[SusanLL]

Jacmoe,

"Fine Grained" not sure what you mean. Too many frames? If that's so, what would be the recommned animation clip?

Thanks for your suggestion-
Susan

[jacmoe]

Yes, I meant too many frames.
I've no idea what a good 'animation frame rate' is, as I am a programmer.
Hopefully, this will spark the interest of fellow Ogre modellers.
They know for sure.

[Kojack]

mesh.XML generated way to large.

The .mesh.xml is just a temporary file (some exporters don't even make it anymore) which is used to generate the final .mesh file. It's the size of the .mesh file that matters. The .mesh.xml is usually something like 4 times bigger than the .mesh (based on looking in my media directory).

The number of animation frames shouldn't affect the size, since they are stored in the .skeleton file. Unless you are doing morph animation though, that has to store entire snapshots of the model for every keyframe instead of just bone movements.


Been a LONG time (6 years or so) since I used the Maya exporter.

[SusanLL]

KoJack

Thank you. I have been pulling my hair out. I figured that the .mesh file was what mattered. I will pass this along to my programmers.

Thanks again,
Susan

[SusanLL]

Well still need some input on this particlular topic.

I have reduced my mesh to 3700 poly's and still get a 3000kb (+/-) .mesh.XML file.

I need to figure out why so much data is being added to the .xml.

Is there a place for me to look over a few character sample models so I can get an idea as to the poly limitations.

Again I work with Maya2011, testing the OgreMax to Maya plug-in, I've even downloaded and installed the FLA add on, which incidentally will not work unless you have the full paid for version of Ogre. At least that's what my test has revealed.

If any modeler working in Maya and has a programming background as well, or not, please chime in and give this gal a hand. I'm meeting with my team tomorrow and need solid answers to give them on this product and if it will perform the functions we require.

Thanks in advance,
Susan

[jacmoe]

Susan: Don't worry about the *intermediate* format.
Convert it to binary and judge that.
model.mesh.xml => model.mesh.

[Kojack]

If we assume that polys are quads, no smoothing is done so there's unique vertices per face, position/normal/uv per vertex then 3700 faces will require roughly 750KB of raw data (around 700KB for vertex buffer, 50KB for index buffer). Apart from using tricky techniques or removing things like lighting (so normals not needed) or textures (so uvs not needed), that's how big it will be in memory.
As I said previously, the xml file is around 4 times bigger than the real final mesh file (which doesn't really matter because the xml file can't be used by ogre anyway. Only the .mesh can be loaded). As it happens your 3MB xml divided by 4 works out to 750KB, which matches my guess above.

Now of course that guess isn't based on an optimal mesh. A simple mesh like a cube looks like it only has 8 vertices, but really it needs 24 vertices to get sharp edges without texturing flaws. But meshes with smooth faces and no creases or instant changes (like texture coords) can reuse the same vertex many times. So if your 3700 faces are all triangles and they are smoothed, it might take maybe 3700 vertices in the file. But with quads instead of triangles (most modellers are referring to quads when they say "polys", but graphics cards only understand triangles) and no smoothing, those 3700 quads become 7400 triangles which become 22200 vertices.

If you are using more advanced looking models with shaders, instead of just position/normal/uv per vertex, you might need position/normal/tangent/diffuse/specular/uvw1/uvw2/uvw3/uvw4/boneweightings/etc.

It's very hard to say how much space something will take on disk without knowing how it's modelled, how efficient the exporter is, what features are required by the shaders, etc.

Of course you can also put meshes in a zip file and ogre can still read them. Looking at torchlight's media zip, most meshes get halved in size by zipping.

Again I work with Maya2011, testing the OgreMax to Maya plug-in, I've even downloaded and installed the FLA add on, which incidentally will not work unless you have the full paid for version of Ogre.

I'm guessing you mean OgreMax or Ogre FLA at the end, because there is no paid for version of Ogre, it's free and open source.

[metaldev]

FLA add on, which incidentally will not work unless you have the full paid for version of Ogre

If you are referring to the LFA add on, I second what Kojack said - you should be able to use it together with Ogre for free - and I should know because i wrote it

@SusanLL
Just to clarify, the LFA Tools were not designed to work WITH OgreMax. They are an alternative to OgreMax.
(Not that you can't use both on a single project, I'm just being clear that neither was designed to work with the other and they both have a lot of parallel functionality)

[SusanLL]

metaldev,

Thank you for clarifing. I need to go back over your setup because I can't seem to get the all the features to work. Can't remeber what the error message was, something about not finding the path to Oger.... Will re-install and try again.

I was wondering, since I can't recall, was the download from your site for the FLA, is it compaitible for Maya2011 64x vista?

Thanks for all your help, will likely have to touch base with you at a later time if that's ok.
-Susan

[SusanLL]

Kojack,

Thank you for following this strand. I showed your responce to my programer/team and you helped to support my findings.

Now I can tell you that based on our end product we have to utlize the XML files, but it's possible that my latest testings will work for their current and future needs. Will let you know if interested.

On the issue about Ogre not for sale but open source. That I'm still not clear on. When we look at the site (http://www.ogremax.com/?q=downloads ), which is where we downloaded the OgerMax Scene Exporter plug-in for Maya, it shows a purchase price for a full version. Not sure what that intells. Or if we really need to purchase it. If you work along side the developers of Ogre maybe you can clarify for us.

Anyway, thanks again all for your expert knowledge. I have found most info very helpful and informative. Looking fowrard to shairing info as the weeks go on.

-Susan

[mkultra333]

What matters, the size of the file on disk or in memory? If you must use xml, and the size on disk is the issue, then perhaps you can simply zip the xml and incorporate a zip decompressor into the project. I'm guessing the xml will be 1/3 to 1/4 the size or less once zipped.

[metaldev]

I was wondering, since I can't recall, was the download from your site for the FLA, is it compaitible for Maya2011 64x vista?

It should work fine since its written in MEL.
The thing about 2011 is that i don't think anyone has compiled the plugin yet for 2011. You can get the source here (The latest I have is the Ogre plugin for Maya 2008). After compiling and installing the plug-in, if you have any problems you can post here or on my site.

That I'm still not clear on. When we look at the site (http://www.ogremax.com/?q=downloads ), which is where we downloaded the OgerMax Scene Exporter plug-in for Maya, it shows a purchase price for a full version. Not sure what that intells. Or if we really need to purchase it.

At the very top of the page you linked, it tells you the limitations of the free version of OgreMax:
- Only one texture coordinate set will be exported per mesh.
- Only one texture unit will be exported per OgreMax material.
- No support is provided.

[SusanLL]

Wooo WHOOO.

Well I finally produced an .xml file with animation that was around 1100kb. Now waiting to see if that's an acceptable parameter for programmer.

Now the crummy part. I updated the viewer and converter to the latest release. Was able to generate a small enough size after playing with the export settings. But I have two small problems.

1. Seeing some geometry pull but it's never in the same direction in test export. Not sure if it's the viewer or a weight issue. Awaiting programmer to see if anomaly is in game.

2. Figured out how the LOD generator feature works. But it causes texture display distortion. My question is, do I generate the lesser LOD with proper texture mapping, and if so how do I tie them together in the export without increasing my .xml to much more?

Well that's where I'm at as of yesterday. If anyone could offer some feedback that would be great. In the mean time, awaiting second character rig and animation and see if I can duplicate production.

Adios compa
Susan

[SusanLL]

1. Seeing some geometry pull but it's never in the same direction in test export. Not sure if it's the viewer or a weight issue. Awaiting programmer to see if anomaly is in game.

Well this is not an issue anymore. Must of had some weight issue on an influenced point.

But still working on the LOD issue.

-Susan

[Banano]

Hi Susan, still there???

I recommend you to try this exporter:
http://www.ogre3d.org/forums/viewtopic. ... 00&start=0
it worked for me. Its from a german Animation Institute.