ArmA Modelling Basics

[Sennacherib]

Oh dear

YES you CAN use a smaller normal map with a larger texture, <span style='font-size:9pt;line-height:100%'>AS LONG AS THE RATIOS REMAIN THE SAME</span>. I.e. if you have a 1024x512 texture, then the normal map needs to be 512x256, or 256x128, or ofcourse 1024x512.

[Edit to add] Although this brings little to no benefit (aside from saving a little bit of gfx RAM) so theres really not much point. [/Edit]

And lets not even begin to go down this "Bump mapping Vs. Normal mapping" road (again, for the 4346456456 gajillionth time) ArmA supports a very specific set of normal maps, as listed on the wiki:

# _NO - normal map
# _NS - normal map specular (with alpha)
# _NOF - normal map faded (mipmaps fade the texture in distance, usefull for terrain)
# _NOHQ - normal map high quality
# _NOVHQ - normal map high quality

However, technically speaking, normal mapping is a variation of Bump mapping. But for simplicities sake, lets just call it "Normal mapping" since thats the standard used throughout the engine.

What you describe as the "high polys model- low polys model method" is not called "bump mapping" but is a method for generating bump (or more usually) normal maps, by using the details of a high-poly, high-detail model to generate a normal map for a lower poly mesh.

thx i didn&#39;t know that but i agree with Neph, it&#39;s better to have the same size for the normal map and the diffuse map, to have better details.

and when you use 3dsmax, you can see the difference between 512x512 or 1024x1024; it&#39;s not the same quality. And if you use the cage tool, it&#39;s better to use the same size for both maps.

[cl10k]

@ d@nte: neph said it would be clever to have a large normal-map for adding lots of prezise details and a smaller diffuse...

[Sennacherib]

lol, i need to buy glasses

but one thing is also important. when you make a normal map (bump map method), with the texture which is used in the diffuse map, i mean an overlay metal texture, if your bump map doesn&#39;t have the same size, you will have some problems (i use the same metal texture for the diffuse and the normal map texture, but with modifications; i use the bump map method for the vehicles). this is the same thing for the specular map, which is used to add realistc lights on the texture.

[DM]

but one thing is also important. when you make a normal map (bump map method), with the texture which is used in the diffuse map, i mean an overlay metal texture, if your bump map doesn&#39;t have the same size, you will have some problems (i use the same metal texture for the diffuse and the normal map texture, but with modifications; i use the bump map method for the vehicles). this is the same thing for the specular map, which is used to add realistc lights on the texture.

Could you please clarify exactly what you mean by the "bump map method" so as to prevent any ambiguity.

(I have a feeling you&#39;re probably using the wrong name for a method, but please describe it so we can either correct it, or you can proove a point )

[Sennacherib]

second part of the tut:

http://forums.cgsociety.org/showthre...?f=46&t=373024

[DM]

Ahh, ok.

So you ARE making bump maps... But...

You are aware that they wont work in ArmA right?

ArmA REQUIRES the RGB Normal Maps (the ones that look blue) and wont work with greyscale bump maps...

[Johannes]

normal map:


bump map:


While bump mapping perturbs the existing normal (the way the surface is facing) of a model, normal mapping replaces the normal entirely.

[DM]

Cheers Jonny, that should clear that up once and for all

[cl10k]

take a look at the (real) normal mapping tutorials on cgsociety...
bump mapping is something different&#33;

i dont want to provoke another bump/normalmapping fight, but as far as i know you can either create your normal map in 2d using a photoshop plugin or similar tools (quite ok for hardsurface stuff) or you use a highres (usually done in zbrush or mudbrush for organic surfaces) and a lowres model and let your application create the normal maps automaticly based on the highpoly-surface...

one example for using the highploy/lowpoly method (quite impressive imo)

http://forums.cgsociety.org/showthre...?f=39&t=479896

good night

edit: deadmeat and jonny were faster

[Adumb]

See why i didnt get into much about normal/bump mapping?