I am a Newbee. I can't see my model. I migrated from SKU to Twinmotion where it loaded perfect. Then as a datasmith to UE5.2 game model 1st person view. I see all the materials. But where is my model?

Although I have been here before, the Forum tells me I only joined 7 minutes ago? Now why is that? I can find anything of my multiple previous postings. The forum recalled my name and login etc
I am also at a loss on where to post my question as I don’t know all the lingo.
My biggest problem with Forums and tutorial,s they don’t tell us the “why” they click on one button or setting rather than another one and all the name and vocabulary a newbie like myself don’t know.
All this adds to the difficulty to ask the right question about the right issue in the right section of this huge Forum to get help.
I think a Youtube tutorial on how to use this Forum would help. Just minutes ago I could not find this frame where to put all this text although I am on a big screen .

So after two years of intense 3D building work, I finally managed to take a 2GB SKU file as an fbx (that took 5hrs to write with my 32GB of Ram I think I need the double) into the newest Twinmotion.
To my GREAT enjoyment it loaded very well (as per 1st render without new materials foliage cars and people)
I have done many before in Lumion with no issues and have over 1000 renders.
as per one example shown here.
I never managed to make Datasmith work with my SketchUP 2019 and UE.

In a previous post long time ago someone told me that Datasmith does NOT function with SKU19 since then I have been reading up and finally thought how about if I can get my file into Twinmotion and then Datasmith it would be a good way to load it into UE 5.2
I did this two days ago and here I am stuck like a understandably like a newbie again. I see all my many materials loaded as per screenshot
but I am lost for words and tutorials one where to find and see the structure of my entire building?
It is 18 levels over and underground. (as per SKU render)
Did they not migrate arrived within the “export to UE Datasmith file or not?”
What did I do wrong when exporting from Twinmotion?

Please as beautiful as they are,
I can’t bare watching one more tutorial about creating castles and Alice in wonderland surrounding.
Please anyone show me a tutorial of importing a real sharp architectural oriented building and not just a villa in a garden all about the great reflection of the windows.

This is my first at building a game, I am no big studio and I am dying to put a capsule on Steam to get onto the “wishlist bandwagon”
(that I should have started two years ago as a learned not long time ago.)

So for me to show my project in UE is so much needed to go ahead.

It’a all happening in a weird wonderful and surprising city block (to grow later)
and it’s not about running and killing.
Thank you for anyone’s help

PS: Anyone on YVR BC Canada. I am dying to get to know someone else who is
into UE …none of my friends are.

maybe is an issue about normal, flipped normals. if you go inside the building can you see the missing polygons?

if not then is a nanite issue. if you have nanite enabled. check the nanite visualizations mode see if the polygons are create correctly

you should also double click the model and play with nanite settings to see if ou find a percentage where the polygons show correctly.

(even if the missing polygons related with nanite was different for me on 5.1, they always appeared black. but maybe something changed)

finally check if the UV are correct. also try to create a default one color material with no textures and shaders and apply it to the model, see if the polygons show up

Thank you very much
I will attempt all that
I need to find everything
I did export the model FBX double sided
to Twinmotion (where currently I am trying to find how to make very detailed lettering
as per Lumion render) to show in Twinmotion
I am battling to get out of paying software packages
I worked to hard to get so much detailed signeage that simply
vanished in Twinmotion. I found out by limitting the emitter colour light from the sides and the edges of lettering (created in in SketchUP) that the letters look much sharper.
(compare the words “light” and RAINBOW that was not constrained then as “Light”
Thanks for taking your precious time to reply to me
truly appreciated
May I ask what is DORU software?
But yea this is another problem that does not address your initial reply
sorry for that.