Exporting .STL format issues

bcrozzy

I recently finished my first sculpt. Its very heavy with detail. When I export it, its a massive file. 1.04GB to be exact. This is way too large for printing purposes. How can I compress the file down to a more reasonable size? Other highly detailed models I've seen are usually around the 30k kilobytes range. Below is the sculpt before adding textures.

I also noticed that it doesn't show any subdivision levels and very low remesh. I didnt do much remesh on this piece. I subdivided 3 or 4 times after primary forms were laid down.
Here is what I see currently

EDIT:
I also spoke with a buddy of mine who uses Zbrush. I sent him the file to see if he could make heads or tails of the issue. He pointed out that all of the model faces are shattered. Like something went wrong in the export stage.

Frank4472

bcrozzy Im guessing the issue is the massive amount of polygons (very dense mesh). To shrink the file you’ll need to reduce your poly count. This will reduce the amount of detail so it’s a hard balance.

Another thing to try:
Which format STL are you exporting in? Binary will usually be significantly smaller than ASCII. Did you try exporting on OBJ format? Sometimes the OBJ will come out slightly smaller as well.

JavierEdo

bcrozzy it looks like the file was exported as an ascii STL file, that will make it very big in disk size. Binary STL should make it smaller.

Most 3D printing softwares allow importing OBJs as well, OBJ files should be smaller too than the ascii STL.

As @Frank4472 points out, the large file size is down to the amount of polygons, having said that, depending on the 3D printing software you use, it may be able to import the file.

How many polygons does the mesh have? Can you try rebuilding a sublevel on it and try exporting the lower sublevel as a test? Does your 3d printing software import OBJ ?

I was recently testing importing a 14 million quads (3GB) OBJ into forger and it turned out ok, only iPadOS itself (not the app) struggled with the file at times, and AirDrop was a bit inconsistent/wonky so I had to use the USB-C port and transfer it that way but other than that forger should be happy to deal with huge files.

Please note that the resolution slider is only used when performing a "Remesh", the value itself does not matter as long as it isn't doing a remeshing action, you could set it to the minimum or maximum and it wouldn't change anything as long as the "Remesh" button isn't pressed 😉

bcrozzy

Frank4472 i actually exported it again as binary. File dropped to 250mb which is far more doable. I wanted to test the limits of the app and my Ipad so I pushed the faces to about 2million+

bcrozzy

JavierEdo Exporting as binary was the key. I imported the file into Chitubox with no issues. I did have to resale it way up but it appears to be working just fine with its current polygon count.
I am curious though...is it a safe assumption to say that by scaling the sphere up before sculpting, that it will increase the memory being used? Having to rescale up in Chitubox by more than 500% to achieve a decent size bust of about 6" tall, will wash a lot of the detail out. So I need to scale up before exporting obviously.

Frank4472

bcrozzy scaling, I believe, doesn’t increase the number of polys or memory being used. You can duplicate an object, scale one, the remesh them both and see that the number of polys stay the same. The larger objects polys are just larger.

Essentially, you can just see the larger objects’ polys are bigger/ scaled up. In order to get “high def” when scaled up, you would just need to remesh at a higher level to break up the larger faces.

on another note, as far as scale, forger uses a measurement of “units”. There is no direct correlation to inches millimeters or anything like that **until you move it to another software. At that point, whatever unit of measurement the software uses, it converts Forger’s units into.

Due to this, it sometimes makes it hard to actually know how big your object is being sculpted. One thing I’ve done to give me an idea of the scale is to make a measurement device outside of forger and import it into forger. Kind of like a ruler with marks that protrude out of it every 10 mm and every 100 mm.

JavierEdo

file sizes depend on the data being written into them, some formats are easier than others to predict but in general it is possible to know a ballpark number of the file size depending on the amount of polygons the mesh being exported has, this does not have anything to do with the world-coordinates-location of their vertices if that makes sense.

You could have a mesh where all vertices are overlapping each other at the origin (0,0,0) and it would still take up just as much as with all vertices in their positions.

Scaling up/down should not cause any detail to be lost, if it does, something else has gone terribly wrong. A scaling operation is only a matrix * vector multiplication, as long as the matrix isn't wonky it should come out ok.

A separate issue would be that a human head model with a polycount of about 2 million printed at 1/6th scale size would look super detailed... but if you make it 1/2th or 1/1th scale you might find it needs "more" detail, in the 50+ million range (to say something) but then again, the scaling operation shouldn't affect vertex positions (there should be enough range for floating point accuracy to not mess up)

Since you mentioned Chitubox, I must say I use it as well, and OBJs load fine too, I personally prefer this format as it works well on all 3D softwares, but files are going to be certainly larger than binary STLs. 😉

bcrozzy

JavierEdo good to know. I have another question too. I managed to export as binary and get a clean model for printing except when I set up supports I notice the model isn't solid. Any ideas?

bcrozzy

JavierEdo is there any chance you might integrate a decimation system in the app? Is it even possible? That, I feel, would allow for much higher polygon sculpts and maintain the small file size for easy transfers.