Faking Bump Maps With Math Node
Skill Level: Beginner / Views: 1623
Quick and dirty method for faking bump maps in Poser based on existing texture map instead of adding another image to memory.

Faking Bump Maps With Math Node 1
Not everyone has the supercomputer they dream of using for their renders; I am one of the crowd that has to cut RAM corners wherever I can just to get a scene to render. I have one dear friend whose computer cannot even handle rendering shadows at the same time as the rest of her scene, and gods help her if she should want ray-tracing! This is frustrating, and if you have an old machine limping along and whining any time you try to render an image you learn that the fewer images you load into Poser the better it runs.
Here is one of the little tricks I use to save RAM--instead of making a bump map for a texture, I just use the original texture.
I am using Michael 4 as an example. Here he is without any bump maps or special shaders, just plain (hi-res) texture map plugged into the main diffuse channel.

Smoooth. But with that scruff he'd much rather be craggy, so I'm going to throw some bumps on the poor man.
Open up your material room and select the material zone to be bumpified. Then go to the Bump channel and right click to open a new node, and navigate to math_functions, as below:

Set your bump value to whatever you like--.0005 is a little high for my taste but it will show the results more dramatically for tutorial purposes, so that is where I've set mine. On your Math node, select Subtract from the drop-down menu and give value_2 a value of 1.00. Then drag a connection from your texture node to value_2:

Note the dark areas now turned bright--these will be where your bump map is raised. Obviously this will work better with some maps than others. You'll just have to eyeball it and make sure you are not causing warts or blisters (unless you want those). But there it is, and the result below:

Voilà! Now you have a bump map of the same resolution as your master texture without adding the few megabytes of RAM that a real bump map would take up. Enjoy!
Here is one of the little tricks I use to save RAM--instead of making a bump map for a texture, I just use the original texture.
I am using Michael 4 as an example. Here he is without any bump maps or special shaders, just plain (hi-res) texture map plugged into the main diffuse channel.

Smoooth. But with that scruff he'd much rather be craggy, so I'm going to throw some bumps on the poor man.
Open up your material room and select the material zone to be bumpified. Then go to the Bump channel and right click to open a new node, and navigate to math_functions, as below:

Set your bump value to whatever you like--.0005 is a little high for my taste but it will show the results more dramatically for tutorial purposes, so that is where I've set mine. On your Math node, select Subtract from the drop-down menu and give value_2 a value of 1.00. Then drag a connection from your texture node to value_2:

Note the dark areas now turned bright--these will be where your bump map is raised. Obviously this will work better with some maps than others. You'll just have to eyeball it and make sure you are not causing warts or blisters (unless you want those). But there it is, and the result below:

Voilà! Now you have a bump map of the same resolution as your master texture without adding the few megabytes of RAM that a real bump map would take up. Enjoy!
Tutorial Comments
RainerM 1:45PM Fri, 14 August 2009
LaQuiet 1:33PM Thu, 13 August 2009
RobynsVeil 6:59AM Thu, 13 August 2009
visionastral 12:13PM Wed, 12 August 2009
Minyassa 9:55AM Wed, 12 August 2009
IsaoShi 9:42AM Wed, 12 August 2009
AntoniaTiger 6:26PM Sun, 09 August 2009
nruddock 3:33PM Sun, 09 August 2009
eschen 9:55AM Sun, 09 August 2009
JudibugDesigns 3:52PM Sat, 01 August 2009