Sign in to follow this  

Just how alright will I be if I were to skip normal-mapping?

This topic is 1320 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I don't really get the use of normal-mapping. Graphics cards have triangle output ability, fillrate, and math power.

 

Normal-mapping uses fillrate in the form of an extra texture lookup (right?), and even more math power, to save triangle output.

 

The problem is, math power and fillrate are much more precious on a graphics card than triangle output. You'll hit limits on them faster.

 

I've seen slides showing a 20k model using a 1 million k normal map, being 10x faster than using a million k model with no normal map. The only problem with this test is that a 20k model with a 1 million k normal map, is going to end up looking like a 60k-500k model, not a 1 million k model.

Share this post


Link to post
Share on other sites

Thanks guys. You saved me from the mistake of not using normal-mapping!

Share this post


Link to post
Share on other sites

It's also important to point out that one really useful property of normal maps in modern games is in detail maps. Forgelight (the Planetside 2) engine and probably others have a normal map atlas they use a UV channel for detail normals on a lot of their meshes. When you get close to models the pixel shader looks up the detail normal and uses the atlas to map it along the object creating much finer details. Like being able to see stitching on cloth and fine patterns when zooming into surface rather than a pixelation. You can't really get that detail without really pushing the tessellation shaders.

Share this post


Link to post
Share on other sites

It's also not always 20k vs 1000k; there are other kinds of geometry too, such as a 4-vertex model representing a flat floor.  So 4 vs 1000k can be a big win.

Share this post


Link to post
Share on other sites

I think you'll burn in hell when chosing not to normalMap tongue.png

 

But more seriously, the needs depend on the situation I guess. Pumping an extra 10k triangles into a character model instead of using normalMaps may also get you where you want, without bringing the videocard to its knees. But think about the environment. How much tris would a level cost if every brick-wall was modeled like, well, a real brick wall? The polycount would explode with every extra square meter you make.

 

You also see more and more "detailNormalMaps", a secundary (frequently repeating / tiled) normalMap to simulate the micro-structure of a certain material. Cotton, bumpy skins, leather, rough concrete spickles, wood nerves, et cetera. Even if the video-card would laugh about it, the artist that has to model your stuff won't! NormalMaps can often be recycled for various cases, and in some cases its enough to "cheat" by converting a greyscaled photo into a normalMap. Production-wise easier than modeling each and every detail.

 

Then again if you won't see the surfaces from nearby, there is less need to have a normalMap of course. When peeking around in other game's texture packs, you may notice that ceiling textures are often a bit simpler, without normalMaps. Reason? You're not looking at the ceiling all day, are you?

 

 

I think/hope that rendering will get more towards displacement mapping, or whatever its called these days. So (nearby) geometry would get tesselated into much smaller patches, and have their vertices offsetted by a "bump-" or "heightMap" kind of thing. That may kill normalMaps one day maybe, although you still need that extra texture of course.

Edited by spek

Share this post


Link to post
Share on other sites

This topic is 1320 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this