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Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 8:49 am
by face_off
You say that feedback so far says that people dont want their specular color to be reproduced? I dont understand. Many materials need colored specular... How about translate it to grayscal value if the color is 100% white and an rgb color if its anything else. I dknt see the value of ignoring the specular color. If i set an rgb specular color in modo i want an rgb specular color in octane period. And i dont want to have to set up an override for two dozen materials that come in from clients that dont have octane for modo. I want as LITTLE work as possible to render from an already set up modo scene to an octane rendered scene.
It was originally an RGB Color node, but the feedback was that this was unnecessary, and that is should be changed to a Greyscale Color node (embedded in the material node). I am just doing what I am told
I will add a Preferences option to convert the Specular color to an RGB Color rather than a Greyscale Color.
Paul
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 8:56 am
by cakeller98
You say that feedback so far says that people dont want their specular color to be reproduced? I dont understand. Many materials need colored specular... How about translate it to grayscal value if the color is 100% white and an rgb color if its anything else. I dknt see the value of ignoring the specular color. If i set an rgb specular color in modo i want an rgb specular color in octane period. And i dont want to have to set up an override for two dozen materials that come in from clients that dont have octane for modo. I want as LITTLE work as possible to render from an already set up modo scene to an octane rendered scene.
It was originally an RGB Color node, but the feedback was that this was unnecessary, and that is should be changed to a Greyscale Color node (embedded in the material node). I am just doing what I am told
I will add a Preferences option to convert the Specular color to an RGB Color rather than a Greyscale Color.
Paul
I get that. You could do it as a preference, but wouldn't it be 100x better if the color was pure white to convert to only use the % as a grayscale value! but if the Modo specular color is not white (1.0,1.0,1.0) then convert to an rgb color * specular%
That would, IMO, be the simplest and most faithful way to represent the conversion. And for those that believe the rgb color is unnecessary, they would default to have their way too. As long as they leave the specular color at the default white they'd get the grayscale value as it is now!... Right?
Thanks for listening to your users.
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 8:58 am
by face_off
I get that. You could do it as a preference, but wouldn't it be 100x better if the color was pure white to convert to only use the % as a grayscale value! but if the specular color was not white(1.0,1.0,1.0) then convert to an rgb color * specular%
Good idea - if it's B&W it will be converted to Greyscale - otherwise an RGB Color. Then no Preference setting required. I like your thinking.
Paul
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 9:06 am
by cakeller98
I guess that works too IF you multiply the percentage times the b+w rgb value. IOW...
Specular % = 50%
Specular color = 0.5,0.5,0.5
Then use a grayscale color value of 25%
Right?
Just don't ignore the spec color since if you do.... It won't work match
Though I was actually suggesting to only use a grayscale value if and only if the specular color was pure white. Which is the default.
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 9:13 am
by face_off
I guess that works too IF you multiply the percentage times the b+w rgb value. IOW...
Specular % = 50%
Specular color = 0.5,0.5,0.5
Then use a grayscale color value of 25%
Right?
Just don't ignore the spec color since if you do.... It won't work match
Though I was actually suggesting to only use a grayscale value if and only if the specular color was pure white. Which is the default.
I have looked at this some more - and it is not so simple. At the moment there is a formula to calculate the specular value and index according to the rules that Funk has posted previously in this post. This formula does not accommodate a colored specular value. Happy to adjust the formula however you all see fit - but suggest you consult with Funk to determine how the current formula needs to change to do this.
Paul
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 9:38 am
by cakeller98
face_off wrote:I guess that works too IF you multiply the percentage times the b+w rgb value. IOW...
Specular % = 50%
Specular color = 0.5,0.5,0.5
Then use a grayscale color value of 25%
Right?
Just don't ignore the spec color since if you do.... It won't work match
Though I was actually suggesting to only use a grayscale value if and only if the specular color was pure white. Which is the default.
I have looked at this some more - and it is not so simple. At the moment there is a formula to calculate the specular value and index according to the rules that Funk has posted previously in this post. This formula does not accommodate a colored specular value. Happy to adjust the formula however you all see fit - but suggest you consult with Funk to determine how the current formula needs to change to do this.
Paul
There are 30 pages in this thread... And many posts by Funk. And I couldn't find the post you are referring to.
I also didn't mention that I almost always tick the reflection match specular. Not sure if that had anything to do with the math.
Would it be way too much work to post the conversion rules as pseudocode, but actually include the math? If so, don't worry bout it.
. I work better in codespeak than trying to follow humanspeak at least when it comes to reading algorithms.
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 9:41 am
by funk
It's OK. I'll talk to Paul and get the rules updated. My initial rules all used specular color and can be seen here:
http://render.otoy.com/forum/viewtopic. ... 40#p177988
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 9:47 am
by cakeller98
funk wrote:It's OK. I'll talk to Paul and get the rules updated. My initial rules all used specular color
7-up!
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 12:14 pm
by funk
I'm just doing some tests with modo specular/reflection color values and discovered some interesting differences between octane and modo.
1. Modo preserves energy using a monochrome method, while Octane uses an RGB method
NOTE: To see the difference, check out the vray docs:
http://help.chaosgroup.com/vray/help/15 ... htm#energy
Therefore modo and octane will only match if you use a greyscale modo specular/reflection color
2. Modo's fresnel reflections (at 90 degrees / edges of objects) are always colorless like a mirror. Octane tints them with your specular color.
Therefore modo and octane will only match if your modo specular/reflection color is white
The differences become more obvious on highly reflective materials.
I just wanted to mention this so people don't expect perfect matches when Paul adjusts the glossy rules to take color into account.
Re: OctaneRender for Modo Beta 1.52 [TEST]
Posted: Wed Apr 09, 2014 1:21 pm
by riggles
Hmm, it seems to me like there's two different goals here. 1) Convert MODO materials to Octane ones while keeping the look as close as possible to the original and 2) taking advtange of Octane's more physically accurate materials to achieve a better looking result than MODO.
So, is it still necessary to color the specular value of an Octane material like I often needed to in MODO?