Jump to content
  • Advertisement
Sign in to follow this  
roos

Graphics terminology questions

This topic is 4974 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

Hi, In Doom 3, they used diffuse and specular textures + normal map. What's this "specular texture"? Is it the same thing as a gloss map? Basically, a grayscale image where lighter areas are higher value for K_s in the lighting equation? Also, is "dot3 bumpmapping" the same thing as "normal mapping"? If so, then aren't bump mapping and normal mapping more or less the same thing? (since, afaik, dot3 is the most common method of doing bump mapping anyways) Thanks in advance, roos

Share this post


Link to post
Share on other sites
Advertisement
Yes, bump mapping and normal mapping are basically the same.

Normal mapping uses an RGB texture map where the RGB value represents a surface normal.

Bump Mapping typically uses a single channel as a heightmap, that just defines how much displacement there is from the surface. Take the normals of this heightmap and you have your normal map.

edit: Both terms are quite often used interchangeably.

Share this post


Link to post
Share on other sites
Quote:
Original post by WarAmp
edit: Both terms are quite often used interchangeably.


I hadn't seen that, especially as bump- and normal- mapping are completely different underneath, surely (even if they do produce a similar effect, though normal mapping looks better as the normal can be used to light a model more accurately).

Share this post


Link to post
Share on other sites
Bumpmapping is used a general term for all the methods that have as a goal to give the surface a "textured" appearance, giving the impression of small bumps on them without the use of more polygons.

Normalmapping is one of those methods, where you use a normalmap and you dot3 it with the light direction. Emboss bumpmapping(old), EMBM(enviromental bumpmapping(DX6),where you used a set of uv coordinates to pertubate the texcoords), modern environment bumpmapping(where again you use a normalmap to compute the reflection vector) are some others. I'm not sure if parallax mapping can be called "bumpmapping", but I think it could.

Share this post


Link to post
Share on other sites
Great, thanks a lot for the explanations, makes sense now :)

As for specular texture... that's same as gloss map, right?

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!