• Which the release of FS2020 we see an explosition of activity on the forun and of course we are very happy to see this. But having all questions about FS2020 in one forum becomes a bit messy. So therefore we would like to ask you all to use the following guidelines when posting your questions:

    • Tag FS2020 specific questions with the MSFS2020 tag.
    • Questions about making 3D assets can be posted in the 3D asset design forum. Either post them in the subforum of the modelling tool you use or in the general forum if they are general.
    • Questions about aircraft design can be posted in the Aircraft design forum
    • Questions about airport design can be posted in the FS2020 airport design forum. Once airport development tools have been updated for FS2020 you can post tool speciifc questions in the subforums of those tools as well of course.
    • Questions about terrain design can be posted in the FS2020 terrain design forum.
    • Questions about SimConnect can be posted in the SimConnect forum.

    Any other question that is not specific to an aspect of development or tool can be posted in the General chat forum.

    By following these guidelines we make sure that the forums remain easy to read for everybody and also that the right people can find your post to answer it.

FSX, P3D Polygons

CWP

Messages
94
Country
us-nevada
I lost an old model that I had installed in FSX so I read around and found how to decompile it and get it back from the FSX mdl file. I was a bit shocked to find that all the polygons were three sided instead of the four sided that I created the model in.

So the big question is "Does FSX and P3D only allow importing three sided polygons into the bgl and mdl files?"

CWP
 
D

Deleted member 1281

Guest
You can export rectangles alright. Just make a test cube and export it, no problem.

However, in the compile process all polygons are converted to triangles in the mdl. So if you decompile the mdl, you get the triangles, and are basically stuck with them. Some progs such as Meshlab have a make-quadrangular function but it is not reliable. In gmax you can manually delete diagonal edges, but it's a lot of work. In FSDS I don't know if that's an option.
 

CWP

Messages
94
Country
us-nevada
Thanks Mjahn, I spend a lot of time correcting mesh to ensure four sided polygons but if the end result is three sided polygons in sim then there is little sense on doing it for FS models. The bad news for me is that my poly count has doubled for the most part but at-least I know now!...

CWP
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
Messages
32,859
Country
netherlands
The graphics card can only render triangles anyway, so that's why all objects are broken down to triangles.

And it has nothing to do with the polygon count of course. You should only count triangles anyway.
 

CWP

Messages
94
Country
us-nevada
Thank you Arno, that was the bottom line answer I needed to understand. So when considering draw call what is the best way to determine pixels over polygons? (example - let's say I have a flat panel on a model that would contain 1425 polygons because of the round window borders. To render it proper as a two polygon object it would need three 1024X textures split in to six 512 X 1024 sections with an alpha to exclude the window cutout areas. If I use the model part containing the 1425 polygons the part could be rendered using a single tiled 1024x texture split in to two 512 x 1024 sections. In my mind the lower draw call would be the modeled part using the 1425 polygons but I don't know the formula to confirm it...) Where would I look to figure out the best in sim results? Of course I can build the part both ways and try them in sim but I want to do it right the first time.

CWP
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
Messages
32,859
Country
netherlands
Hi,

I don't fully understand your math up there, but less materials and textures gives less drawcalls. So in general that's best for performance.
 
Top