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Messages - Paolo_Giandoso

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1
In the parameters of a substance, is it possible to create a new Input Parameter which is a Integer1 slider and it is only stepping through odd numbers?
If I select step 2 it only goes through the even numbers, even if my min is set to 3.

Tanks
Paolo

2
When creating graph, use for example transform 2d node, than expose offset parameter and in parameters tab change it's mode from slider to Position or Transfrom Offset. This will grant you this circular handle when using your graph inside another graph.
https://i.imgur.com/cD7r1pe.jpg

THANKS @mottomo.jk !!! :D

Do you know what would be the difference between Position and Transform Offset?

3
Hi
Does anyone know if it is possible inside the Pixel Processor (or FX-Map node) to numerically calculate Integrals?
Specifically I was thinking about the Incomplete elliptic integral of the 2nd kind.

Thanks
P

4
Also interested into this, as I have the same issue
+1

5
Totally agree on the road textures case.
+1

7
Hi all
I have been trying to solve this problem for a while which I need for my project. Is there anyone with a strong passion for math and geometry and with time to spare who is willing to give me a hand? :)

I want to create, using the Pixel Processor, a gradient representing all the Normals to a semi ellipse (origin centered and with the 2 semi-axis parallel to the x and y axis respectively) defined by 2 attributes,  Height (b) and Width (a).
Something like this.

orginated by something like this

The parameter Height is basically the minor semiaxis and Width the major semiaxis multiplied per 2.

Every point in the plane should get the value of the angle formed by the x axis and the one normal to the ellipse that passes for it.


It has been quite complicated for my non mathematical brain and so far I only managed to find partial solutions. I solved it using an FX map (the images below) rotating a very thin line around the ellipse circumference exactly in this way https://commons.wikimedia.org/wiki/File:Normal_lines_to_the_ellipse.svg#/media/File:Evolute1.gif but the result is not as good as a gradient done with the pixel processor, as it creates a stepped effect even with thousands of iterations (ugh) and if I make the line thicker (tried that too) it becomes even more stepped.





I also solved it using a distance node on a regular angular gradient masked with the ellipse alpha. This works too, to a point, but is not perfect either. The result is stepped and wobbly (I think because of the jagged edge of the ellipse shaped mask).




Can anyone help me see the light? I'll be forever thankful :)

Ellipse equation:
      y²/b² + x²/a² = 1
Point P on the Ellipse:
      for every x where -a<xP<a
      yP= b√1-(x²/a²)
Point K where the NORMAL in P to the ellipse meets the x AXIS:
      xK = xP [1-(b/a²)]
      yK = 0
Equation of the normal to the ellipse in P:
      (a²x/xP) - (b²y/yP) = a² - b²
Angle  between the Normal and the X Axis meeting in the point K:
       atan2 (xK- xP,yK- yP,) (in Radians)
       atan2 (xK- xP,yK- yP,)/2Pi  (in Turns)


8
 :) Anyone?

10
Thanks Galen! :)
I found also the Normal map documentation quite confusing to be honest. Although maybe is not the right topic here.
Took a while here on the forum to wrap my head around it what to check and uncheck.
As far as I understood:

Normal maps can be exported in 2 formats: Open GL and DirectX
Maya works with OpenGL (normal direction +Y) .
Substance Painter defaults to using DirectX (normal direction -Y).
If your Substance Painter project is set to use DirectX normals and you export maps using the "Arnold 5" export preset, the normal map will be converted to OpenGL.
If your Substance Painter project is set to use DirectX normals and you export using the "Document channels + Normal + AO (No Alpha)" export preset, the normal will be exported in DirectX format.

In Arnold for Maya, in order to correctly display the normal, you will need to adjust the Arnold attributes as follows:

If you are using the bump2D node:

OpenGL normal map [exported using “Arnold 5” export preset] - Uncheck Flip R Channel and Flip G Channel
DirectX normal map [exported using “Document channels + Normal + AO (No Alpha)” export preset] - Uncheck Flip R Channel

If you are using the aiNormalMap node:

OpenGL normal map [exported using “Arnold 5” export preset] - do nothing
DirectX normal map [exported using “Document channels + Normal + AO (No Alpha)” export preset] -Check Flip Y Channel

11
How can I create these dots that drive the coordinates of the node from the 2DView (the ones indicated by the arrows in the attached picture)?

12
Got it.
And I found out what is the equivalent parameter in the displacement node, it is the Scalar Zero Value.

Therefore there are 2 options to obtain the same thing:
Option A: In the texture2D node set the Alpha Offset to -0.5
Option B: in the displacementShader node change the Scalar Zero Value to 0.5

It’s the same thing but the Scalar Zero Value is not supported by the Viewport.

Wish they made it more clear in the Arnold  6 online guide.

13
Thanks Nicolas !  I studied it and it worked well.
Sorry for the delayed answer.

14
Out of curiosity, is it -0.5 or 0.5 then?
Isn't there a parameter in the displacement node to change the midpoint? Is it the same thing then modifying the texture's alpha offset?
I can not find a definitive answer on the official documentation.

15
Hi Luca.
Somehow I missed your reply sorry!
Luckily this was a problem that only appeared in the version of the program I had at work. After an update it disappeared :)
Thanks for the help!
Paoli

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