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View Full Version : use as bump or tangent spaces normals


jgreen827
09-16-2011, 06:39 AM
so i was generating a normal map for the grip of a gun that i am working on. ill admit that i am still inexperienced when it comes to normal maps but i thought when u create one and assign it to your shader that you select in the drop down "use tangent space normals". so i created a normal map, but i actually get better results if I select use as "bump map". whats the difference between then two. why would a normal map yield better results in the bump map drop down? btw i realize the images below arent renders but they still reflect the same results.

normal map:
http://img594.imageshack.us/img594/8334/gripnormals.png (http://imageshack.us/photo/my-images/594/gripnormals.png/)


with bump:
http://img829.imageshack.us/img829/5054/bumpp.jpg (http://imageshack.us/photo/my-images/829/bumpp.jpg/)

with tangent space normals:
http://img408.imageshack.us/img408/5438/normalq.jpg (http://imageshack.us/photo/my-images/408/normalq.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

MasonDoran
09-16-2011, 03:20 PM
the normal map is also rendering the curvature of the handle which is blending with the fine pattern.

Nev4r
09-16-2011, 04:44 PM
normal maps are superior, you should use them whenever you can

a normal map contains more information, 3 channels vs 1.

you should be setting that to tangent space normals (if it is a normal map in tangent space, which they usually are as output from zbrush/mudbox)

I wouldn't necessarily say that the bump image is better, just more pronounced. if thats what you want you should increase the height/contrast of whatever you are generating the normals from, or alternatively you can adjust the levels of the r and g channels of the normal map in photoshop (the bump depth setting has no effect on normal maps)

jgreen827
09-16-2011, 05:51 PM
I am aware that normal maps are superior as they contain the light information or something but what surprises me here is that in the bump map screen it is still using the normal map texture. Either way yes I want the map to be more defined so perhaps I need to adjust some settings when creating the normal map. Btw I am generating the maps in xnormal

xstorm101
09-17-2011, 10:08 AM
You can also enhance the strength of the normal map using the Photoshop Nvidia Normal Map Filter plugin, or just duplicate the normal map on top of itself and set the blend mode to overlay.

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