When to make a HP version of LP...?

mobkon

Hey all -

Have a question about hard surface HP vs LP. In this example, I have my LP and also a HP version I created by throwing in some edge loops around the model. I find sometimes edge loops, especially with a bigger, more intricate model in general can get really messy and tends to have creasing in corners which can sometimes be a pain to fix etc.

LP:


HP:


First question is, when do you use edge loops on hard surface modeling? I went through a tutorial for hard surface modeling from 3DMotive where the instructor just softened/hardened the normals throughout the whole model. No edge loops. Looked ok, but definitely had some jagged areas.

If I have a big metal box type sign up on a wall, should I be bothering making a HP version of this? Or just bevel edges on the LP and forego the HP altogether? I sometimes see people making HP versions of things that don't really call for it. Seems like a waste of time. Am I wrong here?

example:


My understanding is doing a HP version is to be able to get the curvature from the HP into the normal map so it gives the LP better light information around curved surfaces in the normal map.

If anyone could shed some light on this for me, that would be great.
thanks!

huffer

Depends, if you have the texture space and resolution you can make a high poly from that sign and bake it (low poly will just be a box). You'll get soft (realistic) edges and it'll be easy to add a dirt pass, but it will look pretty flat from the side.

If you were to skip on the high poly, you can reduce texture space significantly by reusing parts, but you'll add plenty of geometry, plus now the edges of the letter will be very sharp unless you create a normal map bake for those too...a good solution might be a mix

mobkon

@huffer thanks for the reply. I guess my question really is, am I always going to be rounding edges on hard surface objects? Meaning, adding edge loops then smoothing? Let's say I had the resolution to make a AAA game asset, would I always be rounding the corners of a box and then baking that HP box down to a LP box? Or if the object is going to be far from the viewer, does it matter? Wouldn't I need to bevel the edges of the LP to show the roundness from the baked HP?

MooseCommander

You do not need to bevel the edges of a LP for your normal map to work properly, unless the bevel is so great that the general silhouette of the object has changed.

In regards to whether you need to model a high poly for this object - it depends. If it is really far away from the player's view, then no. If they never get close, it isn't worth it.

However, if this is a portfolio piece, you might as well show you know how to model a HP and bake a normal map. For a game production, though, this might just have a tiling diffuse and normal and no unique normal map. You can always bevel the edges to make it feel smoother. The extra geo is really not that expensive for a few bevels, and polys are pretty cheap on current hardware.

I would suggest exporting a beveled and non-beveled version into the level editor you are using and look at it from the distance a player would see it. If it is a noticeable distance, use the beveled. If not, use the hard edged.