sp3 vector displacement

[nizzen]

Very nice procedure for the grass indeed!

[samuel_bubat]

Some tips for Vector Displacement with Handmade Maps or Procedurals
as far as I understand it. Ok actually most of the things, I found out
with the minimal informations from the manual and a lot of Brute forcing
There are still some things I do not understand.

In case you have a simple noise as displacement Map. Adjust it so you only
have Black and white as colors left, no mid grey tones. Use "High" and "Low" Values
to get a result like this when rendering without Vectoring.



I call black, basecolor and white diplacement color.

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Let´s turn Vectoring on.
We know from the manual that blue is the Z Vector. So set displacement color to
a pure blue RGB 0,0,255 while the basecolor remains black.
The result looks like this.


It looks like it works as expected. But it doesn´t. I did not change the camera for this
rendering. You will notice, the whole object was shifted to the lower left corner.
This is because black acts as a vector as well.

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We know that red and green is the vector for x, and y. So you can just mix in 50% red
and green to shift the object back. (Not 100% !)
So for the basecolor RGB 128,128,0 while the displacement color remains RGB 0,0,255
The result looks like this.


Now the object is back in place, but the displacment still remains in the wrong location.

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Same procedure as with the basecolor, mix 50% red and green to the displacement color.
basecolor is untouched and the displacement color is now RGB 128,128,255



Now the displacement works as expected.

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To make it easier for the next steps we will decrease the blue of the displacement color
to 128. This will effect the displacement ammount. As we know blue is for the Z Vector.

Now we are actuall at the starting point, were vector displacement really starts.
Your base color is 128,128,0 and your displacement color is 128,128,128.
The image looks like the one above, just a little less displacement amount
because of the lowered blue value.


--------------------------

Now we can control the direction of the displacement.

Our values from the last step were
BaseColor = RGB 128,128,0
DisplaceColor = RGB 128,128,128

Set the Red value of the Displace Color to 255
this will result in a displacement vector to the right

BaseColor = RGB 128,128,0
DisplaceColor = RGB 255,128,128



Setting the the Red Value to Zero will result in a vector to the left.

BaseColor = RGB 128,128,0
DisplaceColor = RGB 0,128,128



Same for the Green Value just in the y axis.

Setting values in-between like
BaseColor = RGB 128,128,0
DisplaceColor = RGB 50,128,128
will result in a less stronger vector of that direction.

To make angles that are not 90° you can for example use values like
BaseColor = RGB 128,128,0
DisplaceColor = RGB 255,255,128
wich result in a 45° angle



You can fine adjust angles now by increasing or decreasing
green and red values. Always keep in mind, that you will also adjust
the vector amount when you change the RG Values. If you have a
certain angle, but you want a less stronger vector you need to decrease
RG in the same way. For example, let´s take the 45° Picture.

BaseColor = RGB 128,128,0
DisplaceColor = RGB 255,255,128
Setup for a 45° angle

BaseColor = RGB 128,128,0
DisplaceColor = RGB 200,200,128
result in the same angle but a less stronger Vector

and goes visa verse if you are below 128.

For example

BaseColor = RGB 128,128,0
DisplaceColor = RGB 0,0,128
Setup for a 45° angle in the opposite direction as the previous example.

BaseColor = RGB 128,128,0
DisplaceColor = RGB 50,50,128
result in the same angle but a less stronger Vector



Pretty weird stuff.. to do by hand. I´m also not yet that far
to make a controlled gras or something like this. And for the moment I only tested with a simple plane.

I see that it´s neccessary to use this way for geometry that comes
out of programs like mudbox.

But it would be really great if we could have simplified values
for displacement that is not generated from a high poly geometry.
Like. Value would give the displacement ammount, Hue the direction
and Saturation the strength of the Vector.

But anyway, a great feature.

(I hope I didn´t confuse any pictures or RGB values )

[gagui]

Great post and great information. thank you.

[pnel77]

Thanks for that posted max file!

I'm also a bit in the dark of exactly how that displacement map works, but the end-result looks pretty amazing!

I've done a test with the displacement as in the file, but getting this artifacts on the quad patch (I just saved the displacement map, created a 50 000mm x 50 000mm quad patch and applied it to the patch, 300mm amount - also UVW mapping to fit)

What am I missing?

[Mnietek2707]

Can you post max9 file?

[pnel77]

Sure - here the max file

[skogskalle]

My grassattempt with vector displacement... I think it looks pretty good, not sure how well it works on large surfaces though. The plane used here is 5x5 meters.

I did about 7 or 8 differently colored radial gradient maps. Then I used printscreen to copy them into photoshop where I scaled them down and multiplied them many many times over a 1024x1024 image.





here is the displacementmap if anyone wants to work some more on it.

[percydaman]

cool! mind sharing the max file?

[skogskalle]

You dont need the maxfile... Its just a 5x5 meter plane and a vray sun. The key to getting good quality on the displacement is setting the edge-length to 1. The rest of the VD settings are at their default i think.

I did a test on a much bigger plane, about 40x40 meters and it looked great, but the rendering used 4 or 5 gigs of ram without anything else in the scene... This is greatly reduced if the edge-length is higher ofcourse, but then you lose detail.

[TheMulf]

Thank you skogskalle for the map. Have you or anyone else performed any time comparisons between vector and standard displacement? It appears rather good looking so far, but I have yet to do any deep comparisons.