Weird shadows on polygons

[Anonymous]

Hi, everybody. I have been modeling a helicopter more than a year. From time to time I have been noticing strange shadows but I ignored them. Now, there are too many shadows, and it is hard to guess that the model is a helicopter. What can I do to solve the problem?

[kgokhangurbuz]

Hi;

This is because of Smoothing Groups are not properly adjusted.

First of all, remove all smoothing groups from your object by simply adding a smooth modifier from modifier list. By default, this modifier removes all smoothing groups from your selected object.

If you want to assign the same smoothing group for the whole object, you can either set it to Auto Smooth under the Smooth Modifier options, which will only smooth by the degrees of your polygons, connected to eachother (usually preferred method);

Or,

If you are familiar with assigning smoothing groups, simply do not select anything under your smooth modifier after applying it, convert your object into an Editable Polygon and after selecting the desired faces, assign them different smoothing groups under Editable Polygons > Polygon: Smoothing Groups.

Regards;

[Anonymous]

Thanks, removing all smoothing groups removed those shadows. Of course, now everything is so square. If I try to add any smoothing groups to the problematic polygons, weird shadows appear again.

Also, the second problem I have now is that in front viewport some polygons are dark. This is the problem because I make the material opacity 25%, so in viewport dark polygons turn into transparent polygons. Auto smooth partly solves the second problem, though raises the old one. Any suggestions?

I know that this is a newbie question. It appears when the viewport is shaded. I cannot use "realistic" because the material becomes grainy in the viewport

[kgokhangurbuz · Accepted solution]

Hello, 

These dark polygons are more likely because of the default lighting / shadows of viewports, and less likely because of flipped normals.

I usually use "Hidden Lines" option in Viewport Shading types when i'm modeling with blueprints, i can suggest you that too, since it disables default lighting. Unfortunately, this option does not work with material transparencies, so using ALT+X (Right Click > Object Properties > See-Through) is your "opacity" option with this view mode.

For turning the shadows off, simply click on the viewport shading type, go to Lighting and Shadows, Turn Shadows Off, and Ambient Occlusion Off (Ambient occlusion option here is what causes grainy outputs in Realistic view type of viewports, just for your info). (See the screenshot below)

Regards;