Hey folks,

I'm just trying to figure out why a surface extrusion I'm doing in Maya isn't being lit properly.

So, I have a nurbs circle at the origin that I'm trying to extrude around a curve :

After selecting the circle, then shift-selecting the curve the resulting extrusion looks like this :

It looks like the geometry is being lit from the inside out as the interior of the extrusion looks fully lit & shaded.

Any idea what I'm doing wrong here?

Thanks!

t looks like the geometry is being lit from the inside out as the interior of the extrusion looks fully lit & shaded.

I don't know maya, only blender, but I guess that the normals are inverted. I typically select all affected faces and flip the normals. In blender you have although an option to re-calculate all normals to point outward, I guess that maya has a similar option.

but I guess that the normals are inverted

Yeah definitely what it looks like - no idea why the normals are flipped though - or how to recalculate them :)

Hmmm, managed to fix it by flipping the normals of the nurbs circle I extruded around the curve... I wonder if I've been building my model upside down :)

I wonder if I've been building my model upside down

It just happens from time to time. Sometimes the tool can't predict the right normal direction (eg. when filling holes/connecting points etc) or you accidentally use a negative value for scaling.

It is due to normals, you can select the object and check the normals. Look at the trouble area and you will see that the normal is pointing in an inverted direction. To fix you can do a few things, the simplest answer is to average normals. This does not work for all models so keep that in mind.

EDIT: In maya

(make sure polygon is selected for the menu layout)

1) select the object / faces you want to normalize

2) click the menu option for normals

3) click average normals

Some times, you might need to set the normals to face first. This resets the normals (the inverted ones) and then you can perform the above actions.