Same material, difference in lighting objects

[Anonymous]

When rendering with Design 2011, mental ray without FG and Raytracing, both default material, both meshes, I get one darker object.

I'm used to think I've tried everyting, but don't solve this problem.

What could this be?

[PROH]

Hi. Could be caused by a number of reasons, and your description doesn't quite cut it. What is your light setup? What do your mean by "no Raytracing"? What do you mean by "default material"? We need a lot more information.

A quick guess would be the two object got different materials applied to them. If not, then zip the file and attach it here, so we can have a look at what's going on.

[Anonymous]

My file is attached. See for yourself. 

[Stefan_L · Accepted solution]

The dark one has its normals flipped.
(And scaling objects at object level is bad, evil, sinister, wicked... 🙂 )

[Anonymous · Accepted solution]

Indeed! Never heard of normals...and never knew scaling was something evil. Maybe that explains why my texture keeps messing up compared to the other objects.

Thanks!

[Stefan_L]

Well, they keep messing up when scaling on subobject level 🙂

The scaling thing:

Draw a box, 1x1x1 units,

draw another box 0.5x0.5x0.5 units,

scale the latter by 200%.

Now select the two "identical" boxes,

apply an Edit Mesh modifier,

go to polygon subobject level,

select both top sides,

extrude them by one unit,

note the difference 🙂

[Steve_Curley]

But you're not scaling the 2nd box at a sub-object level. You need to apply separate Edit Mesh modifiers to the 2 boxes. On the 2nd one select all the vertices and scale them 200%, then extrude the top poly. Extrude the top poly of the other (first) box and the extrusions will be the same. It is scaling at the Object level which causes the problem.

Actually, you can do it with just one Edit Mesh if you select the Element which was the smaller box (because it is now, effectively, a sub-object) and scale it before extruding the 2 top polys.

[Stefan_L]

Yes, you're right, as always. 🙂

Spoiler

I - uhm - I just wanted to post an example why scaling at object level is bad, evil, sinister, wicked...

No one understands me...

[Steve_Curley]

Ahh - I see. Kind of misinterpreted your post - sorry about that.

p.s. You can't hide from me, at least not in a spoiler 😛