FSXA Popping models

[Tako_Kichi]

Having sorted out some previous issues it now looks like I have one more to solve before I can release my latest project but I've not had much luck finding an answer so far.

I have a number of vehicle models in my scenery (all made by myself) and some (not all but some) are 'flashing' or 'popping' in and out of view as you pan around. I have double-checked all the material settings and modelling settings between the models that are OK and the ones that 'pop' but nothing obvious was found. Interestingly in the models that 'pop' the glass parts always remain visible so you end up with a line of glass windshields where there should be a row of parked trucks!

Anyone seen this before and if so what was the cure?

 

[arno]

Hi Larry,

From your description I assume you are not using levels of detail, so it is not the switching between them that you are seeing. Is that right?

Two things come to my mind. The first would be to check the bounding box of the objects. If they are too small, it could result in the object appearing later. Do you use animations in the object as well maybe?

The second thing that comes to my mind is missing textures. Did you verify all textures are there? Missing texture can have weird influences on the display of an object.

 

[Tako_Kichi]

Hi Arno

From your description I assume you are not using levels of detail, so it is not the switching between them that you are seeing. Is that right?

I am not intentionally using LODs but it is quite possible that I may have clicked the 'Populate the LODs' button on a couple of the models.

Two things come to my mind. The first would be to check the bounding box of the objects. If they are too small, it could result in the object appearing later.

Can you expand on that as I have no idea how to check the bounding box size.

Do you use animations in the object as well maybe?

There are no animations on any of the models.

The second thing that comes to my mind is missing textures. Did you verify all textures are there? Missing texture can have weird influences on the display of an object.

Each vehicle model has it's own single texture sheet and they are all in place in the 'Texture' folder.

It's very odd that this is only affecting some vehicles and not all so there must be something different in the problem ones but I haven't found the cause yet.

 

[arno]

Hi,

Looking at your answers the textures should be ok. About those bounding boxes, are these cars a separate MDL file or are they part of a bigger file? If they are a separate MDL, the reference point of them is in the middle?

 

[Tako_Kichi]

Looking at your answers the textures should be ok. About those bounding boxes, are these cars a separate MDL file or are they part of a bigger file?

Each vehicle type is a separate MDL file.

If they are a separate MDL, the reference point of them is in the middle?

That's an interesting question for the following reasons:

1. I have variations for some models where I hide certain parts and re-export as a different model i.e. some are open topped and some have canvas tops (I hide/unhide the canvas top) or some are just the vehicle or the vehicle with a trailer (I hide/unhide the trailer parts).

2. At the moment the origins are at the mid point of the vehicle at ground level (X0, Y0, Z0) but in the case of vehicles with trailers that would put the origin off centre on the X axis but still within the model. In the case of the trailers on their own the origin is still at the vehicle mid-point even though the vehicle itself is hidden and therefore the origin is outside the trailer model.

3. In the case of vehicles with trailers I have one type that displays correctly (with no popping) including just the trailer on it's own and two other types that pop in and out of view whether they have trailers or not so I don't think the offset origin is the issue.

I have been closely examining one of the problem vehicles (the least complex in terms of variants) to try and eliminate issues and get that one object displaying correctly in the hope that I can then go back and fix the others. I have discovered that it has numerous colocated vertices when I verify the model using the ACES tool and going through every single part reveals that some parts had vertices or polygons still selected when I exported (I have since made sure nothing is selected but I haven't exported and tried the model yet). I have also made the model have a single root node as it originally had multiple root nodes i.e. all parts are now linked to a parent.

Do you think that either the colocated vertices, active sub-object selection items or multiple root nodes could be the underlying issue?

I just checked two of the working models and one has a parent/child(ren) set-up and the other has multiple root nodes and both are reporting colocated vertices (even though the parts have been welded) and yet both display just fine in FSX with no popping issues.

This is a weird problem for sure!

 

[arno]

Hi Larry,

I doubt co-located vertices or still selected polygons would cause such display issues.

But on the other hand, I have seen a lot of weird bugs over the years, so it would not surprise me .

 

[Tako_Kichi]

This problem has just taken a very interesting new twist!

I took the model I had cleaned up (no active sub-objects, parent/child set up correctly) and exported and placed it as a model in my testing airport using ADE9X and it did not pop at any distance or viewing angle.

I then deleted the model in ADE9X (and it's listing), saved the file without the model and then re-opened and placed the same model but this time from the model library I have (which I had already updated) and recompiled the airport. I then tested and the model from the library also did not pop at any distance or viewing angle.

I then opened my project airfield which has multiple instances of the model. I am using the same library items so in theory the new model should be read. I recompiled the project airport (working on the theory that it should pull the model data from the new library) and on testing the model in question popped again!

I am now going to try deleting all the instances of that model and replacing them with the new library model in case ADE9X is keeping the old data for some reason.

It's odd that it works fine at one airport but not another. I'll be back after testing.

EDIT:
I just deleted all instances of the model in my project and replaced them with the new model from the library. I then deleted the airport .bgl file from FSX to be sure of getting a new build and recompiled the airport. On testing the model popped again!

It works at one airfield but not at the one I want it to! GRRRRR!!!!!!!!!

 

[arno]

If it doesn't happen with any instance of the object and only at certain airports, can it be that some other object is causing this issue?

 

[Tako_Kichi]

After a lot of extensive testing and getting nowhere today I finally decided to try a different approach. Just out of curiosity I deleted all references to the vehicles from the vehicle library I made and instead placed one of each vehicle as a 'model' directly into my ADE9X airport. On testing every single model displayed as it should with no popping from any vehicle at any viewing angle!

I am now wondering if the issue lay with 'LibraryCreatorXML_203' which I used to create the vehicle library originally although using that same library at other airports displayed no problems.

It's still an odd issue but at least I may have a work-around if I place them as models.

EDIT:
It seems that placing only one of each type as a model results in no popping. As soon as I add multiples of each then the bad ones pop again (but the good ones do not!)

 

[jdhaenens]

Larry PM'd me on another forum and although we never figured out what the problem was, here's how we fixed it:

I suggested Larry try to merge the model into a blank GMAX file, A trick Fr. Bill told me about at one time. That apparently worked for one of the models, but not the rest.

I tried everything I could think of for the textures, used the RADItor to check all the bounding boxes, and in desperation, imported the model using Model Converter X. After changing the names and textures, exporting the models from GMAX resulted in visually stable models.

Don't know where the problem was, but importing it from a .mdl and exporting it as a .3ds file with Model Converter X, then importing it to GMAX and exporting it as a .mdl fixed the visual problems. Some of the models required further work like splitting them up by smoothing groups, but overall it was probably much quicker than rebuilding everything.

Jim

 

[Tako_Kichi]

Thanks for all your help on this problem Jim as I was really up against the wall and could not find a way forward. Hopefully tomorrow I can get all the new models placed correctly and get things packaged ready for a final beta session.