Bump mapping help
 

Hi,

just been experimenting with bump maps before starting for real. On my grey base image in photoshop, if I paint one white stripe and one black, in my renders, the white one appears sunken in, but the black one has no effect at all.

Have I got a setting wrong?

thanks,

gubar.

if youve got the grey set to mid greay then you need to change the colour gain to -0.5 in the file node

Hi,

do you mean the alpha gain? I've tried altering it, and the alpha offset values. It makes a difference to how the white is rendered, but the black still has no effect.

cheers,

gubar.

Ok, just tried it with a new scene and it is working now. Don't know why it wasn't in the previous scene.

Another question if I may - even using a fairly high resolution texture (1024 x 1024), after I blur my lines (to fade in and out of the shadow, I'm trying to do some inner chest muscles), the bumpstarts to look pixelated when I render. Are there any ways to avoid this, or are normal maps a better solution? I'm hoping there's a way to sort the bumps, since I've not looked at normal mapping yet.

thanks,

gubar.

Here's an image to show you what I mean:

No one able to advise on this bump mapping issue? Could it be that bumps are only suited to small wrinkles and creases, and not larger bumps?

thanks,

gybar

for something like that I would probably use a displacement map. as it looks loke your trying to get a lot out of the bump map.

I only use bumps for small/medium things, wood grain on a table top, brick textures etc etc.

A bump map alters the normal to make it look displaced where a diaplacement map actually creates geometry to give the detial.

You could try saving your map as a 2048 and give that ago to see if its any different.