High vs Low poly construction

pillowsama

Hi guys, any help would be appreciated, I'm trying to learn more about normal mapping, especially on non-organic objects..

Here is the question, for high poly, I understand that it's often done with many pieces put together, just like real life armors... now, when it comes to the low poly, which is recommended? all in one mesh or separate pieces? Or is it better to build the accessories and some obviously separated pieces with different mesh and leave the rest as one object?

Thnx guys! I've bought lots of books and looked at a lot of different game meshes from dominance war, some of them build it with one mesh, some of them build it separately.. so i'm not realli too sure...

Jesse Moody

hmmm well it depends to be honest. No mesh is the same so each one has it's own construction guidelines I would say. I don't think there is just 1 way to do things man. You just gotta find what will work best for your goal at hand.

Eric Chadwick

A few things that can affect the decision.

1... Silhouette. More pieces generally means higher polygon count, though it can help you with a better silhouette than just a single manifold. But usually all the items are a part of the same mesh, it's one entity, just made of unconnected pieces. Make sense?

2... Customization. Some games let you customize your character, and one way they do this is to pop on/off different chunks of mesh (belts, backpacks, coats, shoes, etc.). Different from the silhouette thing, this usually is done with multiple separate entities.

Often changes are done with texture too, either swapping UVs around within the same atlas so clothing changes between chainmail and leather, or by tinting a fairly-monochrome texture with different color multipliers (red vs. green, etc.).

3... Animation. Sometimes things need to slide across an underlying surface, like an armored shoulder plate over a naked shoulder, so separating that into a separate element helps. But still part of the same mesh entity.

Probably more points I'm forgetting.

Sage

There are a few other reasons to consider building an air tight mesh for low poly meshes.

1. Dynamic LODs. I was told by an AD I interviewed with that now games are going to need air tight models because the lods would destroy the model due to how the code made them.

2. Shadows caused by the game engine. If the model has holes in them the engine couldn't make them correctly. I encounterd this problem with my current client and I found it annoying as hell because I had to spend polies on crap that wouldn't be seen. But I guess that also depends on the engine and vert counts is what really bogs the engine down.

3. UVs, you'll have to model with those in mind. It doesn't make sense to have a huge poly taking up your texture space to save on polies.

4. like stated it depends, and take what I said with a grain of salt cause I don't know everything.

Alex

JKMakowka

Normalmap-lighting looks strange too where the two meshes intersect, and in older engines (depends on the precision of the z-buffer) you will get z-fighting in those areas too.