Why is certain parts of my model invisible?

This may be another issue but maybe someone can tell me…

Sometimes when I import a model from Blender to UE4 certain sides of the mesh are only visible if I’m on certain kinds of the mesh…and literally sometimes I can see straight through certain planes…Does anyone know what I’m fighting with?? If It’s something in Blender?

thank you.

Its not event that theyre not always visiable…
the new sci-fi hallway for example…on the other side of one of thwe doors you can look right through the model…same thing im dealing with…
expect its doing it in an incorrect manner…what exactly causes that??

Hi AttemptD,

What you’re seeing is called a one-sided polygon (or called ‘faces’ in Blender). You will need to flip those polys in Blender and re-import the model. One-sided polygons are actually very important in game design, they maximize performance because if the player isn’t going to see it then it shouldn’t be there.

Check out this Blender Wiki page for more info on Face Tools. http://wiki.blender.org/index.php/Doc:2.4/Manual/Modeling/Meshes/Editing/Faces

With that said, there are ways to allow both sides to be seen in UE4 but you are essentially doubling the polygon output of your model. See the documention on two-sided texturing: Texturing Material Functions in Unreal Engine | Unreal Engine 5.1 Documentation

I hope that helps.

Thanks, TJ

Excellent information sir. thank you.

Just experienced this, your answer helped me solve it in 5 minutes. Awesome info, thank you so much.