This is a question about imported models:
Most of the time, I create models in sketchup and export them to a renderer/slicer/etc. but from time to time, in order to save time, I attempt to import models (mainly obj. or .fbx) from the internet.
Almost every time that happens, the imported model is far heavier than its polycount would suggest.
As an example, I am uploading a minaret I downloaded from thingiverse as an stl.
It had half a million polygons so I used transmoutr to reduce its polycount to around 150k polys but still it is very heavy. I decided to recreate it within sketchup and as you see they have roughly the same polycount but behave very differently:
The one created within SU is light as a feather while the imported is almost too heavy to handle.
(I have a decent system, of 64Gb ram /1080 GTX so the effect is not so noticeable but if I make a few copies it really starts to show)
From my experience, the usual suspects that make an imported model heavy are these:
- sometimes while importing, a single texture ‘breaks up’ into as many textures as the polygons of the model.
- other times, depending on the units of the imported model, each polygon is not attached to its neighboring ones, so the model looks the same but you have a very big edge count.
In this particular example, neither issue applies, so I am buffled as to why this happens. And yes, the imported model has a slightly bigger polycount (170k vs130k) but even if I have two of the native model it is still more responsive than the imported one.
The reason I am asking is to understand better how things work so that I can improve my workflow even with models I create within sketchup.
P.S. I am attaching a link to the file with the two minarets (26Mb), and I have 3 scenes:
“created in sketchup”,“imported” and “both” so that you can notice the effect. (if you don’t notice it you can multiply them a few times until your system starts halting)