grayscale and vray displacment

[mdi]

Hi All.

im doing a job that needs displacment. If I make a grayscale image thats 50% gray I would think that that would have an effect on the displacment, but it does, its raised?

Is there somthing Im missing?

[joconnell]

Heya mdi, the default displacement will raise up a surface on any value over pure black. If you use the displacement modifier with a displacement of 100 for example, a 50% grey value will raise the surface 50% of the displace value so 50 units in this case. Pure white will raise the surface by the full 100 units and black will raise the surface by 0 units.

Now say for example you wanted the surface to go both upwards and downwards you need to make a displacement map where 50% grey is your middle value. Parts of the map that you want to raise up with the displacement you make lighter than 50% grey and parts of the map you want to lower down you make darker than 50% grey. The most important thing is in the vraydispacemod there is a value called shift - this is a master control to raise the surface of your displacement overall. If you set this value to half of your displacement value and make it negative, if means that the displacement can go inwards and outwards equally.

[mdi]

thanks joconnell...thats a great help!

[studioDIM]

The most important thing is in the vraydispacemod there is a value called shift - this is a master control to raise the surface of your displacement overall. If you set this value to half of your displacement value and make it negative, if means that the displacement can go inwards and outwards equally.

Jo, there's also an option to "shift by average", that does just that, allowing you to specify just one displacement value, and having the modifier take care of finding the middle.

Lele

[ene.xis]

i ll never stop learning!
thank u both!