gPoly status update #11

I have made some progress again on the gPoly tool. The two main features I worked on today are finishing the Bezier curves and extending the user interface so that you can edit the texture mapping of the polygons. Since these feature are difficult to explain with text or pictures, I have made a little preview video showing how you could use them. You can view this video here.

Next item I am going to work on is vertex snapping. When that is done I will start laying down the polygons for my test airport. I am looking forward to actually make some real polygons for a scenery.

NL2000 v4.0 release

Over the last three years the NL2000 team has been working hard on making their scenery compatible with FSX and many improvements have been made to the scenery during these years as well. Tonight was finally the moment of the release, the new version is now available for downloading. Given the huge size of 32 GB don’t hold your breath while downloading. You can find all details here.

Compared to the previous version I design less parts of the scenery myself. My involved was mainly with technical advice and with converting objects to the FSX format. In the end that was what I started to develop ModelConverterX for.

I hope you enjoy the scenery!

gPoly status update #10

This evening I have been working on a feature for gPoly that will make it a lot easier to draw curved edges of your ground polygons. By using Bezier curves you don’t have to add many points to get a nice smooth curve. All you have to do is set the begin and end point and use a couple of control points to determine the shape of the curve. In the images below you see a few example I made while testing. The two points at the top are the control points that determine the shape. You can see that by changing their position, the curve has changed.



As you can see from the images I can draw the curves in gPoly now. Tomorrow I will continue working on this feature and check if the texture mapping is assigned correctly and see if exporting works fine. But I am sure this feature will be very useful when drawing your airport layout.

ModelConverterX 1.2 released

A new stable version of ModelConverterX has been released. Especially for users converting COLLADA and SketchUp objects this should mean that they can use the stable version again. Since version 1.1 I changed so much, that we always had to tell those users that they needed the development release. Have a look at this post in the forum if you want to see the most important changes in this new version.

At the moment I am focusing a bit more on the gPoly tool, but I still have enough interesting ideas for ModelConverterX as well. So for the short term the amount of updates in the development release will probably be quite low (many bug fixes).

gPoly status update #9

Just a quick status update for the gPoly tool. I think I got the code working now that will ensure that your polygons are automatically sliced into segments of no more than 100 meter. This ensures that there will be no issues with the curve of the earth in FSX. The same code can also be used to divide the polygons of the airport into different segments, so that not everything uses the same reference point and will be rendered at the same time. Especially for big airports I am sure this is important to keep the performance good, although I will have to do more experimenting later on to find the best parameters.

With the exporting side now sort of working, I will move over to the user interface again. Next on my list are improvements to the drawing of polygons (vertex snapping for example) and making it easier to update the texture mapping of the polygons. While working on those features, I will also be drawing the rest of the polygons for my test airport.

gPoly status update #8

I have now chosen the airport that I will use as a test field for developing the gPoly tool. It is Marshfield Municipal Airport (KGHG) in Massachusetts. So I have drawn some of the aprons and taxiways and am testing now if I can export them correctly to FS.

At first I was exporting with the FS2002 style code used for ground polygons most of the time. As long as I export everything with one reference point things looked fine, but when I divided the polygons over different reference points, to have better control over the performance, I noticed that there are gaps visible between the polygons. In FS2004 the same approach worked fine, so it seems the gaps are caused by the curved earth in FSX. At the moment there is a very useful discussion going on at the FSDeveloper forum about this issue. I still hope that once I understand how FSX corrects the polygons for the curve of the earth, that I can export them again with a compensation so that they line up correctly.

To learn more about this curved earth, I decided to start with exporting the ground polygons as FSX MDL files as well. In these MDL files I am bending the ground polygons so that they follow the curve of the earth. This approach seems to work quite good, although I still have some issues with gPoly not always triangulating the polygons correctly. Between the different MDL files I still see a small gap sometimes, but it is much smaller than in the FS2002 style approach. I hope that by improving my math a bit I can get things aligned correctly again.

The fact that the FSX MDL files seems to work quite well is quite exciting, that would open a lot of possibilities to make better ground polygons. For example with reflection when it is raining or with bump maps. I am looking forward to continue the experimenting.

Which airport?

Now that I can export some basic polygons from the gPoly tool, I am looking to go one little step further. I am looking for an airport that I can use as a test case to develop the tool further, since there is no better way to find bugs than while actually working with the tool on a project. In the end I will be using the tool for the EHAM Schiphol scenery of NL2000, but that airport is a bit too complex for a test airport.

See this thread on FSDeveloper for a little more background on “my requirements” for the airport. But basically I am looking for an airport that is not too complex and not too simple. And since having imagery available is a must, I am likely to end up in the US with the free USGS data available.

So let me know if you have any suggestions for a nice airport. As a side effect of using it to develop gPoly further I might even finish a scenery of it.

Abcoude church in FSX

And here is a screenshot of the church made with SketchUp in FSX. It has been converted with ModelConverterX and is showing on the NL2000 v4 scenery. I am not completely satisfied with the textures yet, they seem a bit too light when viewed in FSX, so I think I will change them a bit.

Oh, and don’t expect to find this object in the coming NL2000 v4 release, since I am too late now to still add it. We are already further in the testing and release process.

SketchUp texturing and FSX conversion

Let’s start with the good news, I finished my model of the church in Abcoude. All the textures have been applied as you can see in the screenshot below. But I learned some interesting things while trying to get that far.


Let me start with explaining my approach to texturing the building. I had decided to make separate texture files for each of the different walls. Mainly because I have not yet found a way in SketchUp to define the UV coordinates very accurately. So trying to map a sheet with many different texture elements would become hard that way. If each wall has its own texture though that becomes a lot easier already. And of course I will use the drawcall minimizer of ModelConverterX later on to still make one combined texture sheet for FSX.

One of the things that I encountered is that I needed to position the texture very accurately, because even a small error would result in the textures repeating over the surface and then I can not combine them into one texture sheet in ModelConverterX anymore. So especially for the textures that do not simply fill the entire face that took some trial and error.

One performance related lesson I learnt is that you need to export as COLLADA DAE and not as Google Earth KMZ from SketchUp. When exporting as KMZ (almost) all of the faces are exported double sided, which increases the polygon count a lot. And in the KMZ exporter I could not find an option to disable this, when exporting as DAE there is such an option (and by default they are not double sided anyway). So although it might sound easy that a KMZ has the textures in the same file, it seems better not to use it.

Another performance related issue is that while drawing geometry in SketchUp some additional polygons might be created without you really noticing it. So in the end I spend some time to remove polygons that could not be seen from the outside anyway. I guess this is the price to pay for the easy way to draw the geometry, but it is for sure worth the effort to check and remove such polygons in the end.

So if I look back to this SketchUp experimentation until now I think I have to say that the modelling itself is easier in SketchUp than in GMax (and it seems also more fun). It is very easy to just draw some more geometry. The texturing part I am not so sure about yet, it seems you do not have as much control over that as I am used to. Which can make it hard to make a model with optimal performance for FSX. But it might also be that I still have to learn some more options, so I will continue exploring. For sure it is a lot of fun.

At the moment I am installing the latest test version of the NL2000 scenery, once that is done I will post a screenshot of the church in its proper environment.

SketchUp texturing

After finishing the geometry of the church I am modelling in SketchUp, it was time to move on to the texturing of the object. So also for this part I tried the different options that SketchUp offers.

First I tried to use the project texture function when using the match photo feature. This allows you to align your model to a photo and will then project this photo as a texture onto your model. I guess this might work well if you have an object that is not so complex in shape, but for my church it did not work that well. Since the shape I modelled did not match the real church 100% and because some photos had some distortion as well, the texture never fit properly on the model. I think later I will try this function again with a more simple (rectangular) object, but for now it does not allow me to make textures with the quality I want.

So after that I just tried to import my photos directly as textures (without letting SketchUp projecting them). You can then map them in SketchUp quite easily by putting the pins at the corners of your faces in the photo and then aligning them with the face. This gave slightly better results than the projecting, because you have more control over where the texture goes. But still it is quite hard to align different photos correctly and let the textures continue smoothly over different faces.

So I guess in the end it sounds too good to be true that you can very easily make textures using only photos. My next attempt will be to make the texture in the normal way, by composing it manually from the photos using GIMP. I am sure that will result in the quality I am looking for, just a little more work. I will post the results again once this phase is done.