PDA

View Full Version : possible to make a bump to overlay (Add) another bump?

aphexx
04-09-2009, 04:09 PM
hi, is it somehow possible to make a bump of one material to overlay the bump of another, when blending it?
example:

2 shaders (dust and groundplate) -> blended by a mask -> make the bump of one material, to add above the other bump

the dust should look as if it would had a thickness that lays on the groundplate.
the problem is, that the bump of the dust seems to inlay into the metalplate and is NOT actually on the plate but in it.

currently i only get the desired effect, when using the inverted blend mask as a displacementmap on my mesh. but this increases my rendertimes too much.
and when i put the mask into the bump of the dust, it has no additional effect.

or do i have to put the whole blend shader into another blend shader or comp?
i'm clueless

thanks for any input!!
japetus
04-09-2009, 07:48 PM
Yes, if you are using max 2008 and above check out the Composite map. It works like photoshop layers and you can place a series of layers with bitmaps or procedural maps inside there and use functions like Add, Multiply, etc. I think it would work great for what you wanna do.
soulburn3d
04-09-2009, 09:33 PM
Yes, if you are using max 2008 and above check out the Composite map. It works like photoshop layers and you can place a series of layers with bitmaps or procedural maps inside there and use functions like Add, Multiply, etc. I think it would work great for what you wanna do.

That doesn't work with bump maps. No matter what mode you place the layers in, the composite map will only take the highest level map and use that if you're in the bump slot.

- Neil
aphexx
04-09-2009, 09:45 PM
thanks for your answers!
do you have any other suggestions neil?
i think normal maps could work this way? but they wouldn't be procedural.
soulburn3d
04-10-2009, 01:08 AM
There were two plugins that do the photoshop blend thing called sciananacomp and composite mode, but neither got recompiled for more recent copies of max. What version of max are you running? feel free to go to www.maxplugins.de and look up the term "photoshop" in whatever version of max you're running to see if such a plugin exists.

The other way I've mixed bumps maps is to use an actual mix map. Place the first bump in slot 1. The second bump in slot 2. Set the mix amount to 50%. And then go into the output panel and set the bump amount to 2. That effectively adds two bumps together.

BTW, a bit more on the composite map problem, just in case you're interested...

http://www.neilblevins.com/soulburnscripts/wishlist/wishlist_wrong_bump.htm

- Neil
aphexx
04-10-2009, 05:26 PM
thank you neil!
fortunately scianacomp (http://www.maxplugins.de/r9_files/gohara/sciAnaComp_max9_32bit.zip)is available for max 9 32bit, which we currently use for our rendering project. i will give it a try as also i'll try your trick with the mix map! thanks for that.

concerning your page about the bump problems, i only can assist you!
additionally to your mentioned problems i also always stumble upon problems about the bump colors. meaning, that when using cascading noises in the bump slot, sometimes black and white are switched at rendertime..this also makes the set up of proper bumps somehow frustrating.

i wonder if in 2010 some things have changed concerning bumps, but i fear this problem stays disregarded

btw.: perhaps i'm able to meet you in holland next month.(when my boss will contribute to this journey!) i'm looking foward to it!
soulburn3d
04-10-2009, 10:41 PM
additionally to your mentioned problems i also always stumble upon problems about the bump colors. meaning, that when using cascading noises in the bump slot, sometimes black and white are switched at rendertime..this also makes the set up of proper bumps somehow frustrating.

Yup, that's the same issue.

i wonder if in 2010 some things have changed concerning bumps, but i fear this problem stays disregarded

I don't think anything has been fixed, although my copy hasn't shown up yet, so I can't be sure. All I can do is keep spreading the word about the issue and hopefully it'll get dealt with one of these releases.

btw.: perhaps i'm able to meet you in holland next month.(when my boss will contribute to this journey!) i'm looking foward to it!

Cool, glad you're coming all the way from Germany (well, I guess it isn't THAT far really). Feel free to say hi after any of the talks.

- Neil
CGTalk Moderation
04-10-2009, 10:41 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.