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View Full Version : render artifacts at seams of contiguous objects



Archigram
06-25-2004, 08:02 PM
If you want to render continuous surfaces composed of two contiguous objects (say two adjacent cubes forming a rectanglular solid) how do you get rid of annoying render artifacts at the seams? I can't use smoothing since the objects need to be animated into their adjacent position, and smoothing only works on seams within a single object; for the same reason, I can't simply merge or weld shared points (unless, egads, I would need to artfully substitute a new object whenever contiguous surfaces were formed!) No amount of anti-aliasing works. This seems like such a simple problem--I must be missing something obvious. Thanks for any help,

db

G3D
06-26-2004, 12:18 AM
that will help identify whats going on.

Archigram
06-26-2004, 06:38 AM
OK here's an image.

Archigram
06-26-2004, 06:56 AM
Sorry, can't seem to successfully attach either a .jpeg or a .png file.

liquidpope
06-26-2004, 07:09 PM
Is this what you're talking about?

With two same-sized objects, it's pretty easy. But I have a feeling you really need many, irregular (or at least different sized) objects, that fall together to form one object. Not as easy, but it can be done, no problem.
But if the edges of your objects are rounded or beveled, it's never going to look continuous. Because physically it isn't.

What I did was map the same picture on these two cubes, but I offset the position of the image by half of the size of the cube. In this case I mapped on the z, moved position on the x.
I was exact about the measurement, which was easy because I had the same size and shape object. Anything else will follow the same basic stategy, it'll just be harder to line up the image. For instance, if you're trying to create each of the United States coming together to form the whole country, you'll have to offset the position of the image differently. Same technique, though.

If you can post a picture, I'm sure we can help you better.

Archigram
06-27-2004, 08:14 AM
I'm sorry about my incompetence, but every time I seemingly attach an image (of permitted size and file type) it fails to show up in the preview or post. Anyway, liquidpope, thanks for your detailed response, but I'm not mapping anything, my surfaces are very basic-- no bevels or curves, it's just a matter of forming a larger continuous surface out of lined up objects, as you've shown with the 2 cubes. I sometimes get a thin light or dark broken up line here or there along the seam, and over the course of an animation the lines move up or down the seam noticeably.

Wait a minute: On testing a hunch it looks like the problem here is my large zoom factor (I'm going for an isometric look.) When I render a problem frame from close in the lines disappear. I guess I'm doomed since LW8 still has no true isometric camera, right?

db

JamesCurtis
06-27-2004, 09:23 AM
You are right - it doesn't! But there are plugins that can create isometric views. Right now I can't think of the names of 'em, but you can search www.flay.com using the word isometric and it should give you a list.

Archigram
06-27-2004, 12:19 PM
Yeah, I've looked at these in the past, and of the few that work with Macs (my platform), they seem to be all versions of the pull back, zoom in type, which leaves me where I started. Anyone know different?

db

liquidpope
06-27-2004, 02:44 PM
I just tried the "pull the camera back and zoom way the hell in" trick, and I got the same results as I did in my original post.
Doing the "camera out/zoom in" thing didn't give me any render problems at all.
I'm going to guess it's a texture problem, not a camera problem.

After re-reading your posts, I'm thinking maybe it's simply an alignment problem. How did you build all the pieces, and how are you animating them?
I built mine with the joining edges on "0" x, as one object. When I animated them, I started with the pieces together at frame 30, and moved the one piece up, and KF'd that at 0. That assured the alignment was perfect throughout the animation.
A little backwards, actually exactly backwards, but there's no eyeballing the final placement of parts.

All of these are guesses, as we haven't seen any posts yet.
When you're posting, look down to the left at the Forum Rules. Does it say "you MAY post attachments"?
If all else fails, you could e-mail us a screenshot or whatever image you might have.

Archigram
06-28-2004, 07:11 AM
I checked the original alignment of my objects, which I made with grid snap on, and all the points exactly line up. Then in my scene file, I checked the position of the objects (and their parents) at problem spots and they are numerically exact. (I don't line up by eye but rather enter end points for animation in numeric fields.) Again, my surfaces are simple: no textures, no mapping, no shaders.

I have 2 images (png files) which I will try once again to attach (it says I may--though I wonder if the problem is "html" off. Can this be changed?). Liquidpope, your email link doesn't seem to allow attachments. If this doesn't work, apologies for my denseness. In any case, the images show 1) a thin black dashed line along the seam between two simple rectilinear objects forming a continous plane at very high zoom value and 2) the artifacts gone at low zoom value (same frame.) I do really appreciate everyone's help and concern.

db