Stange anomalies in Sketchup8
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Hello everyone. I hope this is the right forum to post this in. I'm not really sure if this is a bug or something that "I" am causing by lack of knowledge or incorrect modeling technique, but here is the problem.
I recently started using Sketchup8, and am not familiar with the "solids" tools yet. But I have a model of a computer case I've been working on and during a recent "move" operation, some very odd visual elements appeared in the material "image". Since I'm not familiar with the solid thing yet, I modeled the metal panels by "extruding" a "surface" 1/32", after makeing various cutouts and holes. One unusual aspect of the REAL case, is various "indentations" in the sheet metal, which I couldn't figure out how to make the model indentations appear correctly, so I simply made them another piece of sheetmetal offset 1/32", and then I tried to "soften" the edges, which was successful on those indentations which were "raised" above the top plane of the sheet metal, but those that were opposite(true indentations) would not soften, as I believe it was due to the edges being on the INSIDE of the element vs the outside edge.
After creating one of the "indentations" as a element, I tried to move the entire element, but all of a sudden, all kinds of triangle shaped "images" appeared in the material, with no visible lines at the edges. I rationalized this was due to some kind of math the program uses to identify hidden points in space but that is pure conjecture. However, I am curious what causes this, and how I can prevent this in the future.
Not only did I come across this anomaly, but some other unusual things have occurred as well. One is a doubling and offset of a surface such as one of the surfaces in the sheet metal. It appeared out of the blue, and at first, I thought maybe I had accidentally "copied" a surface, but after seeing the first one, I was very careful when copying cutouts in the model. I might add that I may not be doing things in the most correct way, and if someone sees a better way of doing things I am all ears.
I am working in very small units(1/32") and maybe this has something to do with it. But as a long term Pro detailer, I am very oriented at drawing things in real scale and as much detail as possible. Anyway, any one have any ideas on what could be causing these anomalies?
Here is some .jpgs of the computer component I am working on. This is the Hard drive cage.
This is on the underside of of the cage panel
And here is an example of the "surface copy" anomaly. What is really wierd is the copy is where the "real" surface is supposed to be(1/32"), and the real surface is not where it's supposed to be. I assume this because of the "corner edge" connects the two "real surfaces" and not the copy. Anyway, maybe someone can shed some light on this for me.
This is the cage "sectioned"
and this is a closeup of the section point.
Thanks for any insight.
fitZ -
@unknownuser said:
After creating one of the "indentations" as a element, I tried to move the entire element, but all of a sudden, all kinds of triangle shaped "images" appeared in the material, with no visible lines at the edges. I rationalized this was due to some kind of math the program uses to identify hidden points in space but that is pure conjecture. However, I am curious what causes this, and how I can prevent this in the future
If you grouped that before moving it will be fine, ungrouped it will effect all geometry attached to it.
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Wow! that was fast!DOH!! No wonder. What a dummy.
I knew there was something I forgot. Dang, old age sucks.
Thanks a mill. I'm curious though, "what" is this "geometry" you speak of that causes these strange image anomalies? Are there "hidden" trianulation geometrys or something?One other question. How do you make things like sheet metal "solids" instead of hollow entities?
BTW, here is the whole front panel of the case.
And here is the rest of the panels
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The long skinny triangular highlights are "virtual edges" or OpenGL "stress lines" created where you punched those holes and I believe it is Sketchup and OpenGL trying to justify the face fills, especially if the major faces have been moved out of plane. That is, some of the surfaces may have become ever so slightly distorted out of plane.
Like Solo said, group the geometry and then copy.
Real scale in Sketchup and Blender? Naah. There is some window dressing called Imperial and Metric units and fractions of an inch. In fact, these programs use proportional units, if any. That's why metric works so well. You could call it Angstrom units or nano-blips for all it would matter.
Sketchup and, I believe, Blender are surface modelers.
Autocad, which has been a 3d modeling app from the getgo, is a solid modeler and has the capabilities for the precision you seek, but it might cost a little more.The drill[in a nutshell] for Sketchup work is to scale the model, or component up 10's to 100's of times for intricate stuff and then scale back down when complete.
Even after these revelations, I and many others are still using this program. -
@unknownuser said:
Even after these revelations, I and many others are still using this program.
Hey mitcorb, thanks a mill for the insights. Yea, regardless of the i compromises Sketchup uses, I still love the program and use it daily. I would like to know one more thing in regards to this latest "anomaly".
After punching these holes, to represent the "bend" in the metal when it's forged, I used the ruby for "beveling" the inside edge so I could simply add the component to it that looks like it is the face of the indentation. Well, when it performed the operation, I forgot that some of the holes need a reversed bevel as those have a raised element instead of an indentation. However, when I tried to erase those beveled edges, it appears that Sketchup somehow manipulates the "material" as an image...ie...there are NO geometry or lines that define those bevels. The "texture image" is somehow modified to create an illusion of a bevel. See the "texture" highlighted when I click on the surface of the metal? Now I can't erase these. Dang this gets complicated for such a stupid model.
Anyway, how can I change these bevels after the fact, as I've done many other operations since I "beveled" those edges. 
Another thing is copying a hole. When I place it on the surface, SOMETIMES, the hole automatically appears, but other times, I have to trace one of the lines, and then the outline of the cutout or hole appears as a surface, which I then have to erase BOTH cutouts on both surfaces. I can't figure out why sometimes it works, and other times it doesn't. Maybe something to do with groups as sometimes I have groups within groups. Anyway, thats my problem now.
ps..HMMMMMM, after making a jpg...the surface wasn't shown as highlighted. Oh well, just another anomaly to work around
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This may not be the answer, but select something in the model and call up Entity Info( either right click it or Window> Entity Info. These bevels may show to be Softened, Hidden and Smoothed. Uncheck all 3 of these. See what happens. I am just speculating here, I have not actually done this. Anything you change can be undone.
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@unknownuser said:
These bevels may show to be Softened, Hidden and Smoothed.
Hi again. Sorry for the delay getting back to you. Thanks a mill for some more insight. I was wondering though. What's the difference between "softened" and "Smoothed"? Another thing, when I edit these groups, I can window the opening with a bevel, and a blue "highlight" DOTTED line appears as the outline of the bevel/opening. But I can't make it do anything..ie...erase. But I'll experiment with these. Always good to know what to expect when doing these kind of things as far as workflow goes. I HATE having to do things two or three different ways to make something work.Also, today I did some research on the difference between "surface" modeling and "solid" modeling. I came across this site that had an animated video, showing a surface that is being modified in a way that I've never seen. Take a look. I hope the animation works here.
Ok, if you can see the animation work, do you know what kind of program allows you to "stretch" a surface in the way this animation is doing, or even the name of an application that does this. I'm quite impressed with this tool. Kind of like when I found the Sketchup "Push/Pull" tool. That convinced me to use Sketchup. But this "tool" in the animation is a total mindblower.
Is there any tool in Sketchup or maybe a plugin that does something similar? Thanks a mill. -
That looks like Thom's not-quite-ready Bezier Surface:
YouTube - Bezier Surface - Development Demo
[flash=480,385:6zzh3sy1]http://www.youtube.com/v/2tLC0oIbKS0?fs=1&hl=en_US[/flash:6zzh3sy1]What else is available now? Possibilities:
http://forums.sketchucation.com/viewtopic.php?f=323&t=25801&start=0
http://forums.sketchucation.com/viewtopic.php?f=323&t=5475&start=0
http://forums.sketchucation.com/viewtopic.php?f=323&t=22709&start=0 -
@fitZ:
What is the source of that animation that you show above? The geometry is highlighted as if in Sketchup. I have not explored any other model programs but Rhino, Blender and Autocad due to time restrictions. Just curious. -
Hi guys. Thanks for the links Jim. I checked them out. Very cool. Gotta try some of this stuff as soon as someone links to a physics Ruby for MORE TIME
@unknownuser said:
What is the source of that animation that you show above?
Hey mitcorb. Sorry it took a while to get back here. Too many irons in the fire. But here ya go....http://fireuser.com/articles/solids_vs_surface_modeling_what_and_why_you_need_to_know/
I did some more research though, and I'm curious about NURBS now. I recently purchased a new i7/975 computer and am in the process of researching GPU's for SLI as my motherboard is an EVGA 3xSLI Classified. I want to get into Rendering stuff, but lack of $$$$$ keeps getting in the way.
In the meantime I'm researching which way to go for Sketchup/Rendering vs $$$$$ vs 2x or 3x GPU's vs overkill vs budget. 
I'm actually holding off on downloading anymore plugs for Sketchup untill I get my new computer GPU upgraded and my apps loaded. Which may be a while. So, for now I just have to keep modeling simple stuff on my old P4. Well, enough babbling. Time to get to work. Thanks guys.
fitZ
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