Ornament(al windows) in games

Coffeehouse

Hello,

what is a prudent way to do things like these in 3D (3dsmax) for games (UnrealEngine)?

https://www.google.de/search?q=india+window&safe=off&rlz=1C1SFXN_enDE605DE605&espv=2&biw=1559&bih=1307&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjJkbO2qJrKAhVDchQKHY7UA90Q_AUIBigB

Does it make sense to have those ornaments as alpha maps  or is it better to have them as real polygon meshes or is there even something else?

I was thinking of tracing the ornaments in Illustrator and importing the paths and then extruding but was thinking that there might be a lot of polygons to handle if you do a whole building (or city) this way.

musashidan

Build it as high poly as you like and bake the normals down to the low poly game mesh. Then create an opacity map. There are different methods to create the opacity map. You could detach the faces where the cutouts are to a separate mesh and bake a material ID map for instance.

Coffeehouse

Thank you, Muashidan.

If I have a high poly mesh and a normal map that is projected on a low poly version. (Why) do I still need an opacity map?

I mean if it is really modelled it will have the actual see through areas already in it, won't it? So there is no need for further opacity maps, right?
I thought it made sense if I just have the extruded silhouette of the window and then apply an opacity map with the ornaments in it ... or am I misunderstanding something?

I am still a beginner who has not really done anything presentable yet.

Thanks.

Coffeehouse

musashidan

Well, you have both options: Model it into the low-poly and trade off your opacity map for a higher vert count, or: Model a simple facade in your low-poly and let the normal/opacity maps fo the work.

Coffeehouse

I just did a dirty test to illustrate what I was thinking about. I took a AI path, extruded it and set it next to each other to create an ornamental window. I especially want it in conjunction with atmospheric light and interesting shadows. But these five windows already have 200.000 polys, 40k each. That seems a bit too much, right?

I also dont see a lot of possibilies to reduce the polycount while keeping the overall shape.

I didnt successfully try the opacity thing already. Didnt see how to add depth to that. It is probably possible though. Would that give me a comparable effect at low gpu/cpu cost?

Coffeehouse

So I just tried to add an opacity map. See window 1 and 3 from left. I suppose that will be good enough. If I find out how to add depth/thickness to an opacity map it would probably be nicer.

musashidan

Use a normal map for the depth. Just make sure to bevel the high-poly as a flat surface won't read well, and will lack depth.

DRoss3d

I found this on the forums a while back. I hope this helps.

Coffeehouse

Thanks Dross3d. Yes it helps. I don't even know what albedo maps and paralax maps are, not sure about heightmap either (is that the same as bump?), but I will read up on it.

Thanks again.

LaurentiuN

Coffeehouse said:

Thanks Dross3d. Yes it helps. I don't even know what albedo maps and paralax maps are, not sure about heightmap either (is that the same as bump?), but I will read up on it.

Thanks again.

Here you go.

Paralax - > https://en.wikipedia.org/wiki/Parallax_mapping
Hight - > https://en.wikipedia.org/wiki/Heightmap
Albedo - > http://www.marmoset.co/toolbag/learn/pbr-practice

Coffeehouse

Dross3d, do you still have a link to that post you mentioned? I researched a bit more about this and am not getting it done ...