How To Deal With Face Shading Issues?

krispy1001

Resource contributor
#1
Hi Everyone!

My question is how to remove problems with face shading issues. Below you will see a test piper arrow that I am testing. And you can see by the markings in red that shows the shading issues that I am having with this model. I know that there are several different ways to try too eliminate this issue. Method 1: adding loop cuts and dragging the loop cut to both sides of the area that is giving you the shading issue. There by making re-leaving edges for that area and decreasing the angle of each face. Method 2: Using edge split. Method 3: Marking hard edges and then applying the edge split modifier.
I have tried all of the mentioned methods and I can not remove the shading issues. Is there something else I can try?
Does anyone know what else I should try?

I also have a question, what is the best method for starting aircraft design; Should a person start a model using an object like a cube? Or should you start a model with a plane?
I would be very thankful for any help in this area!

Images Below for first Question:

Face Shading Issue:

Wire Frame of model. I am using mirror and subdivision Surface modifiers





Thank you very much Krispy1001:)
 
#2
It is really up to you how to start to model. To me the cube is not the best option to start with. If you are polygon fan then start with face plane (extrusion method). The best one is NURBS, NURBS curve.
Shading issue:
Apart of your 3 methods that have mentioned, try to Remove doubles and Check your normals, recalculate or flip. But because you have subdiv surf modifier on it may not help.
Honestly I cannot see the big trouble there... What about smooth/flatten shade, try flatten it, see what happens..
It also may be an optical illusion, add some light source and move around, try to render with some reflection on...
 

tgibson

Resource contributor
#4
Your shading issue below the cockpit window is possibly due to the non-linear track the edges of the polygons take. Look at the polygon edges that form the horizontal line 3/4 of the way down the fuselage directly under the cockpit window (left edge). Not linear at all.
 

krispy1001

Resource contributor
#5
It is really up to you how to start to model. To me the cube is not the best option to start with. If you are polygon fan then start with face plane (extrusion method). The best one is NURBS, NURBS curve.
Shading issue:
Apart of your 3 methods that have mentioned, try to Remove doubles and Check your normals, recalculate or flip. But because you have subdiv surf modifier on it may not help.
Honestly I cannot see the big trouble there... What about smooth/flatten shade, try flatten it, see what happens..
It also may be an optical illusion, add some light source and move around, try to render with some reflection on...
Hi Mr. FsFox! Starting with a cube is not the best option that I can see as well. It seems that when I start a model with a cube you run into a lot of trouble when you start adding windows. No matter what I do it seems that I have to add a triangle, and as soon as you do that you are asking for normal shading problems. I think I will go back to starting a model with a plane.

I have checked my normal and they are all calculated for exterior. But I did not think about check to see what it looks like when adding a light source.

Thank you Mr. FsFox I will try that!:D

I'm not at all familiar with Blender, but here's a thread on cross-section modelling which might give you some ideas. Remember it's how it looks in the sim that counts!
Hi Mr. HairySpin!

I will read that thread. Thank you very much.
And I would like to thank you for the prop tutorial that you wrote. It helped me a lot.:D

Your shading issue below the cockpit window is possibly due to the non-linear track the edges of the polygons take. Look at the polygon edges that form the horizontal line 3/4 of the way down the fuselage directly under the cockpit window (left edge). Not linear at all.
Hi Mr. Tgibson!

Yes, I know you are very correct. I was not having good results using the knife tool making the window in a model that I made that was very linear. So I tried something new. It was even worse than using the knife tool. I am going to delete that model and restart, but this time I am going to start the model with a plane not a cube.

Actually the Judel that I am working on is the first model that I created using a cube that is turning out half decent. But I had a lot of help from a lot of you guys. Just to name a few: Capt_X, Dutcheeseblend, Hairyspin, Lionheart, Heretic, N4gix, Ronh, and Kevintampa5

I thank you all very much for all of your input!!!!!:D

Thank you, Krispy1001:)
 
#6
:twocents:These shading issues are why I prefer to control my meshes directly, rather than through subsurf (which is very unforgiving about small imperfections of the base mesh)... You can try to realign the vertices on the side and bottom of the fuselage. Or you could add in some loops in the engine-section. In general, don't move loops after placing them unless you have to (like for the windshield). You could remove the offending loops (X-key > Edge-loops) and redo them with Ctrl+R, see if the result is better. And then only shape the windshield.

I hope this mumbo-jumbo was somewhat understandable. o_O

Take care :)
 

krispy1001

Resource contributor
#7
Hi Capt_X!

Yes, any input helps.

This is a model that a very nice gentlemen that watched one of my video tutorials. He asked me to help him. He is a 79 year old vet that is modeling FSX planes. That is so awesome!:) I think it is awesome that a person from that time period is not afraid to work with a computer. I have worked as a network administrator for several years for a company. And I had a very hard time getting people from that time period to use a computer. So I am trying my best to not let him down by not being able to help him model it in the correct way. I do not want to make it harder than it really is. I hope that make since!

Thanks Krispy1001:)
 
#8
If you're making a game model, sub division is a NO-NO while it how it looks that counts.....you really have to understand how HEAVY this model will be when it comes to vertex or polygon count...too many and the sim will come to a crawl. Subdivision is a form of GENERIC modeling, meaning you create the template which is the low poly mesh that infact represents the high definition mesh. For animations and illustration this recommended but for a game model, you really should get into the habit of working with the mesh directly and adding only the detail that you need!

Wasted polygons are just that WASTED when in fact you could be using them elsewhere! I've seen some rather ridiculous modeling on this forum, of buttons on cockpits that look beautiful only to find several cylinders with over 116 cross-sections.....heck, I've seen guys model aircraft that have over 1 million polygons on here and the same aircraft can be modeled with possibly 1/4 of that!!

The reason you also don't want a lot of polygons is because texturing and rendering will be hard on the cpu or the gpu, the more dense the model is the longer it takes to render it! It can mean the difference between an enjoyable flying experience or an add-on to take pretty sim pictures, as is the case these days, nobody cares about FPS anyway and this attitude is what has led to some rather insane add-ons pushing FSX to the limits! :rotfl:
 
#9
Also, to get back on this conversation on the positive side...can you please show us the "end-result" of the sub-division mesh? That way we can certainly tell why you are getting that rough shading bt I can guarantee you right now that you have too many sections in that area and mesh is real dense .... I'll take a guess and say that it is hitting about 180,000 polys right now xD
 
#10
Hey Mr.FaosFX,
you really should get into the habit of working with the mesh directly and adding only the detail that you need!

Wasted polygons are just that WASTED when in fact you could be using them elsewhere!
You've made a point there that I endorse fully, but don't be overly pessimistic about polygon count. When used moderately, subsurf is not a real problem polycount-wise on today's machines. He's barely hitting the 6,000-mark at the moment...

Cheers :)
 
#11
Everyone has their style of 3d modeling I guess. In gmax when I created fuselages for aircraft, I never started with a cylinder, instead, I created entire spline sections of the aircraft and then created planes and skinned them by snapping it to the spine points, it was time consuming but I got some really good results, the final step after that was tinkering with the polys to get the shading right here and there.
 

krispy1001

Resource contributor
#13
I'm not at all familiar with Blender, but here's a thread on cross-section modelling which might give you some ideas. Remember it's how it looks in the sim that counts!
Thank you Mr. HairySpin!

I think that is the best way to model a fuselage. That is how I learnt when I started with GMax. But I was hoping that it could be done faster and easer with all the new tools that are in Blender. But every time I try to short cut the process I run into problems with the windows.

Thank you Very Much!!!!!!!:D

Krispy1001:)
 
#14
I'm not sure this technique would work in Blender but you can try! I haven't done any spline modeling in Bledner because it would appear that Blender doesn't fully support splines the way gmax does. In Blender if you want to insert a point into a spline in a specific location, you can't, you have to select the two points and then sub-divided it and then drag the newly created point to the new location....why it works like this is beyond me but it is very inefficient.
 
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