Having to reduce models for viewing VR mobile. a few questions


(Michaelduva) #1

Hey folks, Im having to reduce models for viewing VR mobile. a few questions....

  1. would a VR Viewer vs iPhone allow me to not have to reduce models that look great on desktop web browser ?

  2. are there 3d settings y'all can recommend (such as 1 face vs 2 face) that allow a larger model to "get through" an iPhone safari browser and into VR mobile without it crashing ?

  3. any FBX file format users care to comment if an OBJ does "better" w same render on crashing not crashing on mobile ?


(Rémy Bouquet) #2

Hello
1. By "VR Viewer" do you mean a VR headset? It you do, you have to understand that a headset is just like a new screen for your computer. So the performance depends more on the computer behind the headset.
That said, desktop computers are usually more capable, graphic wise, than an iphone, so you may have better performance on them, and may not have to "reduce" your models.
Note that viewing a scene in VR will be slower than the same scene in non VR, as we are rendering the scene twice.

2.Not sure what you mean by "1face vs 2 faces", but as a rule of thumbs, having as few separate geometries as possible is more important than having few faces. Drawing 1 geometry with 1000 faces is a lot faster than drawing 100 geometries with 10 faces (note that sketchfab does some optimisations on your models in this regard).
I can't give you a magic figure of number of geometries and number of faces that will ensure good performance on any devices (so many devices, so many differences) but keep the geometry number as low as possible, and then keep the poly count as low as possible (in that order of priority).

3.File format has little to do with rendering performance.So it won't make any difference if you use obj or fbx.

Though if you experience crashes, could you be more specific on the process that lead to the crash (url of the scene, phone brand/os etc..)?

EDIT: you can also report the issue from your phone, filling this form. https://help.sketchfab.com/hc/en-us/requests/new
It will gather technical information we need (browser version, os, etc..)


(Rémy Bouquet) #3

A little bit more precisio, as I forgot to mention an important thing.
Post process can also be a perf killer, some of them are automatically discarded once you switch to VR.
We only keep Bloom, Tone Mapping, and Color Balance while in VR. While Tone Mapping and Color Balance are quite cheap, Bloom can be expensive so you might want to disable it if you experience poor performances.

We also disable shadows for lights that are attached to the camera in VR mode, as it would require to render the shadows on each frame and would definitely be a perf killer.
As a side note, it's discouraged to use shadows for a light attached to the camera as it can lead to bad shadows artefacts.


(Lettucehead) #4

hey nehon
do you know of any tutorial or flowchart or howto about doing this specifically for sketchfab uploading for any specific software utility
this would be YUGE