Slow 2D/3D preview confuses
Hi,
i just stumbled upon the buttons "2D Preview" and "3D Preview" which i did not use before. After first try i thought they would not work because nothing happened after clicking them. Then i realized it takes 30 to 60 seconds to display the according previews (on an Raspberry Pi). Because this behaviour is confusing i thought about adding some visual feedback that UI tries to load the requested data so the user knows something is happening
![Image: https://i.ibb.co/bRN5dR1/fail-both.png fail-both](https://i.ibb.co/bRN5dR1/fail-both.png)
Comments
Could you open debug tools->network and see if request take that long in your case to get answered. All these functions use regular downloads to retrieve the data. Question one is does requesting files start immediately and when does download start. It is no time intensive work so should only depend on sd card and web speed and a bit of the size. But 3d preview is just a 380kb image so not really that long.
The other thing I wonder if that is a object in vase mode - that might also explain the delay. Vases have not a few hundred layer but many thousand layers as they change Z all the time. That makes the layer file quite big (I see 17mb in your case) and that file is not just copied but it gets converted from a small binary to a json formatted file which also slows down sending a bit. In that case it could be the bottleneck to convert it to json. I tested it with a vase and for the 8.4mb it took 2.5 seconds on a pi 4.
Maybe I should add a extra test that a new layer must be at least > 0.01 mm above layer start height. In my example I had an average layer height of 0.000484 mm. That makes not much sense anyway and is the reason the vase looks so transparent. Not that 0.01mm would change much for this.