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Re: Sketchup furniture objects frequently lose a lot of detail on import. Is that normal?

It's normal. Even if You use AOI.
Here is my acceptable practices:
1. Download a model from 3DWarehouse (in my sample this ) BUT the Collada file format)

2.In a empty SH3D file: Menu ->Furniture->Import furniture (choose the model)

look ugly but continue
Change name and save

In SH3D will look like this (ugly)

3.Select and right click to modify furniture -> Materials

Some of models have some edge components usually in black; select and mark as invisible and OK

4. Save the modified furniture:Menu->3D view->Export to OBJ format...->Selected furniture;
5.Open a new file or clean the previous and Menu ->Furniture->Import furniture
Select the saved furniture and import it under characters (or whatever)
Will look like this

Hope is useful for someone.
A computer program does what you tell it to do, not what you want it to do. Murphy's Law (Greer's Third Law)
If all else fails, get the instructions back out of the rubbish bin and read them. (bluewater - the aptosid manual maintainer)
[Oct 3, 2016 9:12:55 PM] Show Printable Version of Post    View Member Profile    Send Private Message    Hidden to Guest [Link] Report threatening or abusive post: please login first  Go to top 
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Re: Sketchup furniture objects frequently lose a lot of detail on import. Is that normal?

Kevin -

There are several different things going on here.

All right: There are a lot of different things going on here.

The bad news is, you've managed to find one of the very few SketchUp models I've seen so far that can't easily be sanitized for SH3D use.

The good news is it probably doesn't matter.

As you noted, when this model is loaded into SH3D, its textures do not display correctly in the 3D window. Seemingly, some areas of the model become mapped with an incorrect texture ― or at least an incorrectly positioned texture; at times, portions of the model seem to disappear. In addition, as the model's position changes relative to the user's viewpoint, the failure changes: Missing sections reappear, texture positioning changes, and the like. The problem is easily seen in the 3D window, but for the individual models of figures making up the collection, the problem can be seen in SH3D's furniture importer itself. (In the collection, the problematic textures are too small to detect.)

The problem doesn't just affect SH3D's loader and 3D window; as you can see from the following image, the problem is also found in renders at the two lowest quality levels, Q1 and Q2. (Interestingly, the Q1 and Q2 renders fail differently [and somewhat more rudely] than the 3D window does.) However, in scenes rendered using SH3D's high-quality, ray-traced mode ― Q3 and Q4 ― the glitch disappears. Since final renders are typically of high quality, it's likely this problem will have no real impact on your projects beyond minor annoyance during design creation.

[click here for full-sized]

That the problem is limited to the 3D window and Q1 and Q2 renders suggests this is a GPU-related issue. That the problem doesn't occur in high-quality renders suggests the model itself isn't seriously broken. We know this is an extremely rare occurrence ― it's the first incident of the sort I've ever seen, and a scan of problem reports doesn't turn up anything obviously related ― so SH3D's GPU code, if broken, doesn't appear to be badly broken.

<<< Originally, at this point I included a description of how I tracked down the culprit, along with some [most likely unnecessary] background on polygon mesh geometry. >>>

What we can say, then, is while there may be an issue with the code driving SH3D's GPU-based windows, in this case the problem seems linked to the model's somewhat non-standard use of texture files, when those file contain transparency.

I suspect this isn't, strictly speaking, a SketchUp --> SH3D migration problem, but an [Unknown modeller] --> SketchUp --> SH3D problem; that is, this model most likely wasn't originally created in SketchUp but with some other modeling program and then ported to SketchUp. Neither the model's entry in the 3DWarehouse nor its one in 3DModels.vn, seemingly the source for the one in 3DW, discuss its origins. However, based on the extremely complicated texture mapping in use, I can only assume it was created elsewhere: Seemingly, every polygon in the model has a texture applied to it individually ― an insanely time-consuming task if carried out from within SketchUp, but one conceivably easy to automate as part of a model export/import conversion routine.

Still, even this overly complicated mapping scheme doesn't appear sufficient to trigger the problem in and of itself. It's when this complex mapping is paired with textures supporting transparency, though, that the failure appears. Something in this combination manages to confuse the GPU code, causing some polygons to be incorrectly mapped and others to disappear completely.

To test this hypothesis, I extracted one of the original texture files, removed its alpha channel, thus disabling transparency, and replaced the original image within the model with the now-transparency-less version. When this modified model was imported into SH3D, the affected areas of the model display correctly in the 3D window and in renders at all quality levels, as shown in the following screenshot of the 3D window. In it, the figure on the left is the original model, showing the texture issue, while in the figure in the center the texture file against which the dress is mapped has been replaced with one lacking transparency. As you can see, the image now displays correctly.

Unfortunately, this is a work-around of limited utility. SketchUp modelers often use transparency in textures as a way to display more finely defined details than would be practical using model geometry alone; as a result, removing transparency by necessity eliminates these details. For example, in the original model, the designer uses transparency to create the ragged hemline on the dress and the lightly fringed bangs and loose tendrils of hair along the hairline. When the dress texture file is replaced by a non-transparent version, the dress's full geometry becomes visible, with the previously invisible areas now filled with whichever color replaced the transparent areas in the file ― in this case, white.

The rightmost figure in the previous image shows one seeming compromise solution to be unworkable: In this version of the model, the dress texture image was replaced with one making use of transparency only where explicitly needed: namely, immediately beneath the hemline. (In the original texture file, all background areas are transparent, regardless of whether or not they are ever mapped against a polygon.) Unfortunately, the presence of transparency anywhere in the texture appears to be enough to trigger the display failure.

In theory, it might be possible to rework the model extensively so its texture design more closely resembles that typically used in SketchUp. In such a case, areas predominantly of a single color ― the figure's arms, leg, and chest; those parts of the dress without lace or other decoration ― would contain a simple color-based material rather than a photo texture; the latter would be reserved for use only in those areas where they were needed explicitly. Such an undertaking should not be attempted lightly, as it would no doubt require much time and effort to match colors and photos ― and, in the long run, still might not succeed. Assuming it did succeed, the only difference would be a marginally more attractive display during scene construction and the ability correctly to generate low-quality renders: High-quality renders would be unchanged, at best, and more than likely would be inferior to the photo-texture version.

Accordingly, I think your best course of action is to ignore the problem. Do your best to ignore the garbled textures while designing your floorplan, and be sure to render your final plans at Q3 or Q4.

- - - - - - - - - - - - - - - - - - - - - - - - - - - -

Additional findings

During this investigation, I discovered (or rediscovered) a few more interesting tidbits. First up is a rediscovery of a lesson I forget and relearn repeatedly: Namely, the importance of selecting 'Triangulate all faces' before exporting from SketchUp. In the following image, the row of figures nearest the camera was exported with triangulation selected; the row further away was exported without triangulation. The difference is immediately obvious ― and, as the second image illustrates, can be seen in the 3D window, as well.

The second discovery was occasioned by Dorin's comment regarding edge removal from models downloaded from the 3DWarehouse in Collada format. While he offers an imaginative solution to the problem he encountered ― that is, how to make use of a 3DW model exported with visible edges ― and one I suspect will prove useful in a number of contexts, I'd earlier demonstrated it wasn't applicable to the case at hand. For one thing, you exported the .DAE version of the model with 'Export edges' unchecked; for another, the Collada version available from the warehouse does not contain visible edges. However, it does contain other problems making it unsuitable for use in SH3D.

In the image below, the figures are from a model downloaded from 3DWarehouse in Collada format and imported, unchanged, into SH3D. As you can see, most notably in the hands and faces of some figures, object textures do not render correctly throughout. (Based on the way the failure behaves, I suspect the problems are ones that can be corrected by following the steps I lay out in my forthcoming guide to making use of SketchUp models in SH3D. Unfortunately, other issues with the model make this a more complicated process than usual ― especially when the version created by loading and exporting a native SketchUp object needs no modification to render correctly.)

Interestingly, when I attempted to import the 3DWarehouse's Collada model into SketchUp, a warning appeared saying the model could not be validated. The importation seemed to proceed without error; however, the resulting model retained no information regarding 'edge smoothing' (in practice, Gouraud shading), with the result you see in the following image: The model containing the nearest row of figures was created by importing the Collada-format model from the 3DWarehouse; immediately exporting it as, again, a Collada/DAE object; and importing this second Collada model into SH3D. During the initial importation into SketchUp, the model appears to lose all data influencing edge presentation, resulting in all edges being rendered visible, unsoftened, and unsmoothed.

This is presumably a SketchUp issue, as the same Collada file, when imported directedly into SH3D, retains edge smoothing ― as can aslo be seen in the preceding image, where the row of figures in the back belong to this directly imported Collada file.

Unfortunately, though, both models based on the 3DWarehouse's Collada-formatted object contain the surface rendering bugs mentioned earlier. Accordingly ― and supported further by the issues Dorin encountered ― it's probably safest to download objects from the warehouse as native SketchUp objects, load them into SketchUp, and export them in Collada format for later use in SH3D. Please note 'safest' here is a relative term: A vast number of models from the warehouse, on being imported into SH3D, will have textures fail in any of a number ways. Fortunately, virtually all of these failures can be prevented by a simple chain of processes implemented immediately prior to final export ― as documented in my upcoming white paper, "Using SketchUp-Originated Models in Sweet Home 3D," due imminently.
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