New to blender - Strange mark


I’m very new to Blender and I’m following this tutorial on modelling a basic house. When I render, the roof has a small mark on it. And when I’m in edit mode there’s a little triangle near the top right darker than the rest.

What is it and how do I remove it? Thanks for reading.


Not sure what tutorial you’re following but it’s not a very good one.

I can’t see clearly from the pic,post the .blend file.

Care linking to the tutorial,that model is using way too many edge loops.

Hi - The .blend file.

The tutorial I’m using is

Welcome deniedaccess!

Could be a number of things there… a duplicate polygon or an unwelded vert. It’s best to let us check out your .blend file so we can identify it for you. When I first started modeling, I used to do all kinds of crazy things accidentally and not know how to fix it. It’s all part of learning cg. :slight_smile:

Ok… yeah, you have some faces on top of each other. Just select the faces and delete them (x button and select ‘face’). When you have a nice hole there, go to vertex mode (you can click the button or hit cntrl + tab and select vertices) and notice that you have 2 extra verts on that edge that you don’t need. Delete them with x and select vertices from the list. Now select the four verts surrounding the hole and hit “f” (think ‘f’ for face) and make a polygon face there and voila!

This stuff happens sometimes so don’t be too discouraged. Just be brave about deleting faces. You can always rebuild them with that “f” trick. :wink:

Thanks for your help, Tommy.