Starting with Art First

Unicole

I want to start creating 3D art for eventual use in hololens, are there rendering or filetype restrictions? Is this based on the system that it runs on, like Unity? I'm just starting so I want to make sure I head in the right direction.

Jarrod1937

As long as you can export to FBX, everything's fine Unity wise. Other than that, the usual performance considerations apply. The Hololens is more like a phone performance wise, so keep that in mind poly count wise, avoid multiple UV's and textures which will increase the rendering computation. Ideally have multiple models use the same texture. However there are automatic tools for texture atlasing in the Unity Asset Store, so don't put too much thought into that.

Jarrod1937

As long as you can export to FBX, everything's fine Unity wise. Other than that, the usual performance considerations apply. The Hololens is more like a phone performance wise, so keep that in mind poly count wise, avoid multiple UV's and textures which will increase the rendering computation. Ideally have multiple models use the same texture. However there are automatic tools for texture atlasing in the Unity Asset Store, so don't put too much thought into that.

Unicole

Thank you!

HoloSheep

@unicole to add a couple of points to @Jarrod1937 great answer.

I recommend you put some thought in to the location that you set for the origin point of your model (and the pivot points of any children in the hierarchy of the model) before you export to FBX since Unity does not let you edit that in any of its tools. The origin tends to be quit important when it comes to placement, rotations etc.. The common workaround for handling an adjustment to the origin of an object once it is in unity is to dump the object inside an empty gameobject and then offset the model such that the desired origin of the model coincides with the origin (center) of the empty game object. Works, but is a somewhat awkward and a bit of a messy hack. Much nicer to plan that one out and set it before exporting from your modeling tool.

The other thing that is worth considering is that bump maps and some of the fake 3D effects are much less effective in MR and VR since movement in 3D space and stereoscopic viewing allows for angle of views where the bump maps do not add the same kind of value as then do when rendering to a 2d screen. In the MR and VR space you really need real vertex points on the mesh, but of course you have to be careful as @Jarrod1937 mentioned to keep the count as lean as possible in order to maintain 60 frames/sec.

HTH

Unicole

@HoloSheep How interesting! Are you saying it depends on the users height? What if your user base is comprised of people of all different heights? Would you create two versions? I assumed the spacial mapping would account for the location of the users vantage point with regards to the art like it does from a side-to-side but maybe I'm misunderstanding completely.

HoloSheep

@Unicole apologies, I used too many words and poorly in my description.
I think a couple of pictures might help:

Here is an example of a simple model I created in 3DS Max where the origin was not well thought out in Max, and after importing into Unity I realized the origin was not really where I wanted it.

So I used the workaround that I mentioned above to wrap it with an empty object so that I could locate the origin in a better spot on the model for purposes of placement in Holographic space.

With the origin in this second location it is much easier for me to place it on surfaces, where as the exported FBX had an origin that when the model was placed on a surface part of the model would end up below that surface which in my case was not the result I was looking for.

And no, this issue should not have a direct impact on how tall your user needs to be to use your app. Sorry for the confusion.