View Full Version : Odd shading issue

10-01-2009, 04:41 PM
Has anyone else ever seen this one?

Here are two images, one from a still scene, the other from an animation. The larger still image is in a simple scene with a few lights. The smaller image is a frame from an animation that takes place inside the hangar of another object, and has roughly 500 lights in it. But the main object is exactly the same.

Right down the front of the ship is an odd seam. It is on the border between the left and right UV Textures, but is otherwise unremarkable. There are no duplicate/unmerged points or non-planar polygons. The shading angle for both sides is 35 degrees. I even played with dropping it even lower to see the point at which the surrounding polygons started tessellating; that was all the way down to 3 degrees.

Any suggestions?

10-01-2009, 06:57 PM
check for a poligon beteen them _______|______ that is not seen because it's inside.

10-02-2009, 11:16 AM
I can't find any errant polys or points. Well, there were 4 overlapped polys, but they were elsewhere in the mesh.

The issue only appears on the boundry between the polys using the UV texture(s)- the two bands around the body and the window frame don't exhibit the smoothing issue.

I'm uploading a packaged scene with the Harridan mesh - it's not the scene that shows this issue, but is the complete object.

If anyone feels like taking a look, I'd really appreciate it. This is just a hobby for me, so I don't care if people use/dissect the model. Just give me a post or PM if you do, please! :)

10-02-2009, 11:40 AM
I think it may simply be due to the fact that the left and right side are 2 separate textures.

10-02-2009, 11:46 AM
It's possible, but if that's the case, it seems more like a bug. I see the exact same issue in FPrime, so it's not unique to the native renderer in Lightwave.

I've never really played with UVs before this, so I've never seen anything like it. But in all my other objects with two different surfaces next to each other - even with different smoothing values, as occurs elsewhere in this object - I've never seen this issue.

10-02-2009, 12:19 PM
I've been playing around with your scene, moving things around and I can't get it mess up. it always renders fine. could it be single sided light or a shadow on the other scene?

10-02-2009, 12:39 PM
The scene from the animation takes place in a hangar with several hundred lights. They're all spots of varying brightness, all open to 90 degrees. It's possible it's something odd in the engine - I might un-parent a bunch of the lights, kill the hangar mesh, then try another render.

I appreciate you folks looking!

10-02-2009, 01:01 PM
If anyone is curious, here's the scene with the main hangar lights, but almost everything else cut out. It does exhibit the issue, especially around frame 180. Odd.

Thanks again for looking!

10-02-2009, 01:38 PM

I am a dumbass. I took just *one* more look at it, and sure enough, the right side surfaces were using the Right UV for Diffuse, but the Left UV for Spec/Gloss.

What a tool. :(

Thanks again for the help!!