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How to determine the number of vertices of an FGFS plane

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How to determine the number of vertices of an FGFS plane

Postby abassign » Sun Jul 29, 2018 11:53 am

How to determine the number of vertices of an FGFS plane and what is the maximum acceptable limit ?

This morning a guy who is making a plane with a very high quality level, he showed his work to my friend who is making the 3D models of the FIAT G91-R1B and asked the question: currently my model has about 80,000 vertices , are too many ?

How many vertices are there in our FIAT G91-R1B?

Working in Linux it was easy to answer the question with the following method:

Code: Select all
find . -type f -name '*.ac' -exec cat {} + >> allfiles.ac


Without this we have a directory with all the .ac files (you can of course do it differently, but I was interested in having the .ac files all together)
Then we can extract only the lines present in the .ac files that report the number of vertices:

Code: Select all
grep -r "numvert" ./ > counter.txt


I then opened the file in an electronic spreadsheet (Libre office Calc) and I find this:

Number of vertices: 1,385,684
Number of object: 1600

1,385,684 vertices are too many ?

For now I would say definitely not ... I'm using a PC I7 5 years ago without the NVidia graphics card, but only with the internal I7 graphics card that uses, with internal memory, the RAM about 1.8 GB ... Despite this configuration does not change much if I use the reduced version of the plane (about 600,000 vertices, as it is possible to activate only parts of the plane) or the full one (1,380,000). The loading time is about 20-30 seconds, which becomes half when I use a PC 5 years ago with i7 and NVidia 1050 with 4 GB of RAM. With the NVidia 1050 card the full scree frame rate on 2K video is between 20 and 30 with the highest quality effects, clouds, and trees (medium density) that I think is an excellent result for an aircraft with resolution and high quality .

The only difference is that with the i7 machine without a video card (for any type of FGFS airplane I fly) the frame-rate is reduced quickly if I increase the resolution of the video, or I increase the quality of the effects, the clouds, the trees (these are real frame-rate devourers!).

At this point I do not know what the "practical limit" of the number of vertices of an FGFS plane is, but it certainly is much higher than the average size of an FGFS plane.
Reading the indications that are given on the correct use of the Open-GL the real limit is to use too large and too frequent textures as these have a less efficient management, but on this topic I think that others are much more experienced in this argument.

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For the instrumentation we try to maintain a resolution of 50 um with the tolerance of 10° circles. The 3D of the instruments is done by Freecad. The resolution of the textures for all the instruments is 1024x1024 px.

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Our desire is that other friends begin to make their aircraft with greater accuracy in the 3D model because the technology of 4-3 years ago allows you to fly, with pleasure, aircraft with a much higher quality. When you make the 3D model with Blender or a CAD you can be more open-minded to adopt a higher quality, the frame rate is affected much less than the amount of vertices of what you believe.
Last edited by abassign on Thu Aug 09, 2018 8:34 pm, edited 5 times in total.
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Re: How to determine the number of vertices of an FGFS plane

Postby Icecode GL » Sun Jul 29, 2018 12:02 pm

At this point I do not know what the "practical limit" of the number of vertices of an FGFS plane is, but it certainly is much higher than the average size of an FGFS plane.


The number of vertices is not usually a problem. The problem comes when you use too many different textures and many individual models. The GPU doesn't mind getting a million vertices at once, but it suffers when you upload 1000 vertices a thousand times or upload 10 textures instead of a single one.
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Re: How to determine the number of vertices of an FGFS plane

Postby abassign » Sun Jul 29, 2018 12:27 pm

Icecode GL wrote in Sun Jul 29, 2018 12:02 pm:The number of vertices is not usually a problem. The problem comes when you use too many different textures and many individual models. The GPU doesn't mind getting a million vertices at once, but it suffers when you upload 1000 vertices a thousand times or upload 10 textures instead of a single one.


Absolutely true, this is the reason why we prefer to have a higher resolution on details, such as the all-3D instrumentation, which has many textures. This makes the plane look like "out of the factory", which I like, but not others, it would be very interesting to activate an artificial aging through effects as already done, in a very interesting way, for the terrain and the effects of reflection. The only use that we borrow of the textures, in our model, is that related to the textures of the instruments (on average 1024x1024) and of the UV-Maps made to give roughness to the elements obtained by casting (for example the handles). The 3D model of an airplane, if you want to run a high quality criterion, requires some attention and some trick, but in the end the result is excellent.
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