F12: wierd dark areas in models

I am new to Blender, but have about 10+ years’ experience in other 3D apps, including Lightwave.

I’m trying to get up to speed in Blender and making simple shapes to get my feet wet.

I’m noticing wierd black areas or splotches that aren’t remedied by the command for making sure normals are aligned.

the obvious guess is that I’m new to blender, yet I can’t see any glaring blunders in my modeling.

Any tips to get me back on track would be appreciated.

Thank you!


We can’t really help you without seeing the render, as there are a couple possible reasons this could be happening.

Wrong forum. But to answer your question check your model has no internal faces.

Ha! yeah, fair enough… here’s a pic of what I’m working with:


on the left is how it looks like in modeling window…a basic cup. at right is a render after hitting F12. the stuff around the perimeter of the base is what I’m talking about.

thank you!

PS…which is the correct forum to post with these questions?

OK…I see…they’re down lower in the list…my bad!



Looks like that’s a ‘feature’ of edge sharp.

Drop it down to around .9 and see if it goes away.

can you help me out with this…I’m not seeing a tool or button in a panel called edge sharp…

still looking…



I believe it’s inconsistent normals. Go into editmode (Tab key), press A until everything is selected, then Press Cntrl-N to recalculate normals outside. Good luck!

try using the edge split modifier or smoothing your geometry F9 sub panel

My analysis that you need to move your light sources about and see if this changes anything - it’s quite similar to shadows being there.
And a personal preference tip for your bowl - if you are going to render this, let the bump maps do the work for you at the rim where you are having the problem. Ofcourse you are free to ignore my suggestion . …
Welcome to the best 3d program and all the best !

I’d bet you have a non-manifold mesh. Smoothing cannot be done properly because normals are not continuous in that case.

That happens when you have T junctions between faces. Like if the faces making the bottom of the cup join with the sides in a T, where one side is the interior of the cup and the other is the exterior.

It’s best if the bottom is made to have a thickness, like a fat U shape.