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View Full Version : How to make a Bump Map Correctly



Cunhambebe
03-28-2005, 06:44 AM
I've donwloaded Fabio Passaro's Jupiter version 1 at LWG3D and noticed that the planet map used for the surface was the same one for the "bump map" (although in grayscale). This may be a silly newbie question, but I'd like to know how to create a bump map correctly for an image, let's say the same one. I've done this:
1.Open Photoshop, select the Jupiter map (or any other planet map you have), go to Image>Mode>Grayscale;
2.Go to Image>Adjustmentes>Levels;
3.There, you drag both Input Level dark and white arrows to the center.
4.Use this image for the Bump Map.
Is that correct or I'm missing something?
Thanks in advance.

Silkrooster
03-28-2005, 03:25 PM
I don't have photoshop, so changing the levels, seems a liitle odd to me. I could see adjusting them if you did not want pure white or pure black, to lower the amount of bump.
The only other thing, I could add to your list is check for hotspots and shadows. An example a texture taken with a camera and flash.
Silk

Cunhambebe
03-28-2005, 03:37 PM
Thanks for taking time to respond and thanks for your help. Some people at lwg3d have also helped me...please go to:
http://www.lwg3d.org/forums/showthread.php?t=24207

Now the problem is...how to make a spec. map........pffffffffffff
;)
Can anyone help me? Help will be greatly appreciated. Thanks in advance.

Mdust
03-29-2005, 02:12 AM
You seem a little stressed out about this. That is to say it sounds like you think that the images have to be manipulated in some way for them to be maps ( bump specular etc.) Is this the case or are you just trying to do it the best way possible?

You CAN use the same image in color and Lightwave will just use the light and dark areas for mapping.

The advantage of going to grayscale is to be able to have feedback on the data that Layout is actually using to create the bump/specular/transparency/luminosity etc.

From here you can use your bightness/contrast type adjustments in photoshop or whatever and fine tune the effect.

I don't think there are any hard fast rules, just use your eye. And it depends on the images of course -as rooster pointed out. Looking for particular problems etc.

Hope this helps.

Mdust

Cunhambebe
03-31-2005, 11:05 PM
Is this the case or are you just trying to do it the best way possible?
LOL...No stress here...I live near that beach (avatar). Anyone with a "park" like that near home shouldn't be stressed at all, isn't it? I'm used to diving there...You're certainly invited. LOL - I'm trying to do it the best way :)
Now, thank you very much for taking time to respond. I'm new with Photoshop (2 years playing with it and yet, a newbie), that's why trying to make some bump and spec maps is a bit difficult for me. Please I invite you to follow this link..

http://www.lwg3d.org/forums/showthread.php?t=24207

...we came up with a solution for that problem. Thanks again and please don't forget; you're invited.

faulknermano
04-06-2005, 01:42 AM
dont know if this is relevant, but i've found a way to to make bump maps from relief maps. relief maps are lit from one side so there's a shadow area and highlight area.

using photoshop, apply Curves adjustment. then sample the the "highest" point in the relief map using the default eyedropper tool. you will see a marker in the Curves window pointing to the values you are sampling along the Curve. that create a "key" on the Curve based on the mark of the highest point and drag it all the way up. the two other "keys" must be dragged at the bottom so that (usually) it looks like an inverted "U".

the idea is to remap the middle values (which is usually the highest parts of the reliefe map) to something bright (which means height in a bump map), and the shadow and highlight areas into something dark (depression).