surface quality question

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 From:  BurrMan
4358.1 
Hi Michael,
I'm doing some preliminary tests getting ready for a more detailed project and wanted to check on this surface result before i get too deep in...

My question regarding this surface, is if it looks "stressed" or somehow malformed..

Aside from what is an intended undulation, I'm not sure when I zoom in a bit more if the stuff I see is just a shading glitch or an indication of something wrong.

Also, maybe a good means for me to determine this without bothering you about it? Would applying zebra stripes with Rhino tell me anything about it??

So here is a picture from a bit away showing intended surface with some slight change from front to back.



If I zoom to the surface a bit, I'm not sure if what I'm seeing is just shading glitches show up, or a sign of a poor, stressed surface...



This surface isnt something I drew outright, it's extracted from an area resulting from some blends with booleans and fillets attached.

I examined the point structure and didnt see anything overlapping. Maybe some lack of symmetry from side to side (My original creation method)

And a second question would be if there would be anything for me to gain in my model, after i get deeper into it, by running seperate on what would be now many surfaces and running shrink on the trimmed surfaces and rejoining into a solid?

Thanks for your time.

EDITED: 19 Jun 2012 by BURRMAN

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 From:  Michael Gibson
4358.2 In reply to 4358.1 
Hi Burr, that kind of display most likely means that you've got a kind of slightly lumpy/bumpy surface.

When the bumps are small in size, the regular display mesher will not always be able to pick up on them all that well and you'll get that kind of slightly darkened bands where the bumps are at.

One method you can use to rule out a display problem is to export to a mesh format like OBJ and turn the mesh density up to a very high level by using the "Divide larger than" setting, like this:



Then switch the Display option on that mesh dialog to Display:Shaded and you'll be able to see a higher fidelity view of the surface. Also try switching Metallic lighting on and off - bumps do get exaggerated with metallic lighting on, but it kind of makes for a more busy display as well and sometimes the less busy regular shaded display can help to focus in on the shaping.

Then when you're done looking at it, just push escape or push the Cancel button to cancel the export instead of actually writing the file. If you do this frequently you can set up a keyboard shortcut with the command part as:
SaveAs c:\test.obj
that will supply a dummy filename to use with the SaveAs command as part of the shortcut key so you won't have to see the file dialog.



> And a second question would be if there would be anything
> for me to gain in my model, after i get deeper into it, by
> running seperate on what would be now many surfaces and
> running shrink on the trimmed surfaces and rejoining into a solid?

ShrinkTrimmedSrf can actually work fine on joined surfaces as well, so you don't need to do a separate first before doing it.

The main thing that it can do for you is to reduce file size, since it will reduce the amount of data that each surface is using. But on the other hand it also makes doing object repair type tasks like untrimming and retrimming things a bit different - after you shrink it you won't be able to do an untrim to recover the full original surface anymore, you'll only be able to get the shrunken surface.

There is no hard and fast single rule about whether to shrink things or not under normal circumstances. But if you are doing something like cutting out a tiny fragment from some monstrously large and complex surface, then it's a good idea to shrink it though so that the little fragment won't be carrying around the monster huge surface underneath it.

- Michael

EDITED: 28 Jun 2011 by MICHAEL GIBSON


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 From:  BurrMan
4358.3 In reply to 4358.2 
Hi Michael,
"""""""""""""""""Then switch the Display option on that mesh dialog to Display:Shaded and you'll be able to see a higher fidelity view of the surface.""""""""""

Oh yeah baby... That is a GEM!!! Thanks!

That makes me feel better about my surface..

Can you comment on it? Do you think it is a good surface to proceed with (Or maybe, do you see anything wrong or stressed about it)? Or is that kindof an arbitrary question?
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 From:  Michael Gibson
4358.4 In reply to 4358.3 
Hi Burr, well there's nothing exactly wrong with it - it is a bit bumpy there though so it won't win any beauty contest for smoothest surface, but functionally it should be fine. And the bumps are really quite small in size.

> Or is that kindof an arbitrary question?

Well, it does kind of depend on what you are going to end up doing with it...

- Michael
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 From:  BurrMan
4358.5 In reply to 4358.4 
Thank you kind sir!
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