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Best way to model the INSIDE of a shape
jeff_mcaffer
Member Posts: 87 ✭✭✭
I've been working on a relatively straightforward fireplace wall model. See first pic below. Not too complicated. The complexity arises because there are several different surfaces and thicknesses and I have to translate this user/homeowner view into drawing/dimensions that a framer would use. For example, the brownish area is 3/4" cabinet plywood on 1/2" drywall. The lower gray area and mini "hearth" is 1/4" steel on 1/2" drywall, the hole where the fireplace unit goes has no surface, etc etc. There are about 5 different thicknesses ranging from 0" to 1.25". For even more fun, some areas that appear to be one plane for the viewer are actually multiple different thickness materials side-by-side so the framing underneath has to be different. I would also like to be able to flip between both the user view and the framer view as I talk to both and we need to collaborate in the right dimensions/views.
To do this I built the part shown and:
- make the part into a really thin Shell.
- for each different thickness of material, Thicken with the relevant dimension and faces for each material.
- use the fortunate fact that the back plane has clear line of sight to the entire inside front wall and Extruded the back wall outline upto Next (the inside of the shell) to get the basic volume
- Extrude a full depth hole for the actual fireplace and a few fix ups.
That gets the big blue part in the second pic. The cool thing here is that it's just a part inside the shell transparency or explicit hide/show gets me the views I need. The bummer is that it feels like a bit of a hack and I'm left with a bunch of oddities where the Thicken doesn't thicken corners. The third pic shows an example where the sill/hearth was thickened down and the vertical wall was thickened back (red arrows) and nothing thickened the "joint", so you end up with a "ridge" in the corner. The profile in that area should look like the blue lines. While not the end of the world, this detail shows up on drawings and, while people eventually understand, it needs to be explained and casts doubt as to which lines they should believe.
I could of course go through and fill these out in the shell before Extruding to fill the inside but that hassle combined with the hack spidey-sense makes me hope there's a better way. Is there?
Answers
do you want to solve the root cause by cleaning up the model?
or are you looking for the fastest way to clean up the blue part? I'm guessing that would be 'delete face' set to heal…
Well, I like learning better ways to do things so sort of the first. For example, I run into issues because creating the shell requires some thickness. So even using .01" there is a tiny difference between bits faces that are thickened and those which are not. While I can deal with that with dimension tolerances on drawings, they line still show up. What's worse is that my strategy of fixing up the inside of the mold (i.e., the shell) is more complicated as there are little shades of (un)thickened solid keep popping up and I have to account for that all over.
I honestly don't know that my usecase is that common and would/should be directly supported but it sure would be nice to find a clean way to do it.
Having said that, cleaning up the model is an immediate goal. I was not able to get anything to work with the Delete Face approach. At least part of that was due to the aforementioned "hidden shards" but I also don't fully see which faces to delete in that third pic that would allow it to heal appropriately. But I've never used Delete Face seriously. Hints would be awesome.
A quick fix would be move face.
Oh, right. yah know, onshape (and the community) just keeps on giving. Every time I discover some new genre of feature I realize just how much I've been banging rocks and sticks together and I get to rethink design approaches.
This or using the corresponding Extrude/remove works. There is still fussing because of the shell thickness shenanigans but I've accomplished what I needed. Perhaps if I thought of it as a surface or just did a better job of modeling the parts for real, it would get better.