I am working on a new, highly detailed, model which weighs in at nearly 10,000 polys. It seems to run fine in Train Sim as it has a good number of separate groups and lots of separate objects in each group.

I have created a LOD model reduced to 5,000 polys that kicks in at 40m. Again this runs fine in Train Sim.

However, I have had several attempts at creating a third LOD model, with varying number of polys, and cutting in a various distances, but every time I get the dreaded 'Send/Don't Send' message from Train Sim, sometimes just before, and sometimes just after getting the initial cab view displayed.

I have sucessfully created some smaller models with 3 LOD levels before. Has anyone else had this problem, and found a way around it?

I and others have experienced LOD problems.

Have you looked at the model in the shape viewer?
Does the faulty LOD appear to "explode" the model?

I think it is down to a single group using multiple materials and deleting all items of one material in a group.
My latest terrier had the problem.

I made the last LOD the same as the 2nd, removed one part at a time, exported as S then viewed with the shape viewer.
At the point where the model "exploded", I just undid the operation and removed another part instead.

Thanks for the advice Paul. I was thinking I would try this evening making the third level an exact copy of the second and seeing if that worked, then proceed from there.

Would it be possible for you to write a plug-in that would do pre-export checks, listing the following:

• duplicate named objects, and which group to find them in
  
• groups containing items with different specular, etc levels applied
  
• objects in the root level with transparency (if that really is a problem
  
• anyting else that will cause problems with LODs
  

I did once try creating a LOD hierarchy by hand, but the exporter did not like it. I had to copy the original hierarchy and move my new objects into it before it would work.

The newer version of my print hierarchy plugin is reasonably helpful for this - it no longer prints directly, but opens up a document in notepad with material info on the objects.

A more specific plugin would be a bit more useful.

OK, I have re-optimised and re-creased all the object individually, and created a third LOD model as a complete copy of the second LOD model, and it seems fine in Train Sim, and Shape File Viewer. I have also read through the heirarchy listing, and all looks ok.

So I guess I just have to cut down the third LOD model a little bit at a time, and keep trying it. Sounds like a slow process, but at least I can see it as a way forward. Thanks for listening and encouraging

quote:

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Originally posted by Paul Gausden:
I and others have experienced LOD problems.

Have you looked at the model in the shape viewer?
Does the faulty LOD appear to "explode" the model?

I think it is down to a single group using multiple materials and deleting all items of one material in a group.
My latest terrier had the problem.

I made the last LOD the same as the 2nd, removed one part at a time, exported as S then viewed with the shape viewer.
At the point where the model "exploded", I just undid the operation and removed another part instead.

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Paul, when you say materials do you mean object material settings or textures ? As you can probably recall I had the 'exploding' problem with one of mine and they all had the objects grouped by similar material settings.
Is it the fact that some objects are using more than one texture map that could be the culprit here ?

I'm not absolutely certain yet, but it could be different textures used within a group.

It looks like you need to keep at least one object for each texture within a group, rather than just one object in a group.

I have been slowly chipping away at my third LOD model, and have managed to remove a number of objects completely, but I am left with quite a few objects in each group that it won't let me delete, so I am deleting all but one face on each. This is tedious in the extreme.

I have not managed to figure out the rules, but it does look like different texture files, as well as the attributes, is a factor here. I had grouped for light (glow-in-the-dark), dark and normal attributes. I will try regrouping by texture file as well and see if that helps.

I'm expiriencing similar problems,
one of them is using translucency of 2 in LODs seems to crash Trainsimulator, and another thing is that every group in a model has to be populated with at least one object in the LODs. I hope a next version of 3DC can workaround this. BTW the Program Kuju used was able to do this...

OK, I have spent some time, and with the help of the 'Print Hierarchy' plug-in, I have created some new groups and moved objects around so each group contains objects that all use the same texture file and lighting characteristics. I found a few small items that used more than one texture file, so remapped them to use only one. Some big objects using more than one texture file were put into groups on their own (I will not want to delete these big items, just delete some faces from them.

Having done all that, I found I could delete objects at will (provided I kept at least one object in each group) to create multiple LODs without causing MSTS to crash.

Now I have figured out what it needs, I can be a bit more efficient with future models.

Keeping one object in each group is not a big problem as I can delete all but one face from these objects and bring the poly count right down.

Ahh, and now I have found a limit to the size of hierarchy report Paul's plugin will produce. It seems to be about 47k.

I don't have any answers for this as you might have guessed from my lack of a response. It just occurred to me how I could have figured this out. If I had an S file that worked and an S file that didn't work and the only difference between the two was the deletion of a simple object (say an object that contains a single face) I could compare the two files and see what went wrong.

So if you have a model where if you delete a single object the LODs fail then you could:

1) delete all of the faces of that single object that causes the failure except one.
2) Export it to S and verify that it works in MSTS.
3) Delete the single faced object and re-export verifying that it fails in MSTS.
4) give me the two S files and to compare to see what differences there are and what the cause of the problem is.

Richard

Richard, you should now have mail

Is there any definitive answer to the LOD problems experience above other than what has already been mentioned.

I have not found one yet, other than to make sure that all items in a group have the same texture file and lighting settings applied, then delete a few objects at a time, making lots of backup copies, and then trying it in MSTS before going back and deleting a few more objects, and so on. This makes is a long, slow, boring process.

I can sort of see why there is a problem with this from looking at my exporter. Unfortunatley I don't think there is an "easy" way for me to fix it. I don't like to make changes to the exporter since it is so easy to break.

The best "work-around" for this is to keep in mind "the rules" when modelling. A helper plug-in would be nice. But I would guess that Paul's plug-in makes it relatively easy.

Richard

Thanks for the update on that. Perhaps it might be fixed for v7?

Have you been keeping up with the latest developments on the alternative Train Simulators being put together in the wake of the announcement by M$ that there will not be an MSTS2? One of them, at least, will be using the same (or similar) file format as MSTS. There might be support for bump mapping too.

I had planned to make improvements for MSTS 2. But now that is down the drain...

I don't know about 7.0... It is more likely for that then for 6.6. That might be a good idea since I am breaking everything else for 7.0. May as well break the exporter at the same time. I'll have to wait and see where this all ends up on the priorities list. 7.0 is a ways a way and perhaps everyone will be on TMTS by then.

Yes, I am all up to date on TMTS. It looks like it is going to happen. I would guess there is money in it for the RailDriver people. They would probably sell a lot of copies if it is good. I think it is a good niche for a small company. As long as what they produce is a good "simulator" (like MSTS is and apparently Trainz isn't) and graphically it is superior to MSTS then I would think a lot of the more diehard train people will "upgrade".

Richard