why do not absorbtion/scattering ramps work

3D Studio Max Plugin (Export Script Plugins developed by [gk] and KilaD; Integrated Plugin developed by Karba)
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coilbook
Licensed Customer
Posts: 3032
Joined: Mon Mar 24, 2014 2:27 pm

BK wrote:Hi guys :)

I am not really a Phoenix power user, however, my test worked fine with Volume Gradient ramp node. Please try setting up the volume gradient ramp shown below and let us know how it goes.
2017-08-01 17_48_32-Slate Material Editor.png
The attached file is created using a Demo version and the values will work according to unit setup. I hope you will find this helpful.
I will thank you. We have to set ramp value to like 2000 or more because if it is less fire is so bright even with power level of just 0.1 Not sure why emmission power must be so low or fire is very very bright. Also we have to lessen the emission scale
BK
OctaneRender Team
Posts: 1440
Joined: Mon Oct 31, 2016 7:54 pm

coilbook wrote:
BK wrote:Hi guys :)

I am not really a Phoenix power user, however, my test worked fine with Volume Gradient ramp node. Please try setting up the volume gradient ramp shown below and let us know how it goes.
2017-08-01 17_48_32-Slate Material Editor.png
The attached file is created using a Demo version and the values will work according to unit setup. I hope you will find this helpful.
I will thank you. We have to set ramp value to like 2000 or more because if it is less fire is so bright even with power level of just 0.1 Not sure why emmission power must be so low or fire is very very bright. Also we have to lessen the emission scale
Hi Coilbook,

Thank you !! I Please make sure the interpolation type is set to "Linear", also scroll the Max grid value to find the right value.

Is there any chance to share a sample scene through PM?
Kind Regards

bk3d
coilbook
Licensed Customer
Posts: 3032
Joined: Mon Mar 24, 2014 2:27 pm

BK wrote:
coilbook wrote:
BK wrote:Hi guys :)

I am not really a Phoenix power user, however, my test worked fine with Volume Gradient ramp node. Please try setting up the volume gradient ramp shown below and let us know how it goes.
The attachment 2017-08-01 17_48_32-Slate Material Editor.png is no longer available
The attached file is created using a Demo version and the values will work according to unit setup. I hope you will find this helpful.
I will thank you. We have to set ramp value to like 2000 or more because if it is less fire is so bright even with power level of just 0.1 Not sure why emmission power must be so low or fire is very very bright. Also we have to lessen the emission scale
Hi Coilbook,

Thank you !! I Please make sure the interpolation type is set to "Linear", also scroll the Max grid value to find the right value.

Is there any chance to share a sample scene through PM?
Thank you BK

I attached the sample scene. If you can tell me a proper max grid value that would be great. You can go to frame 28 of attached sim or resim it again.
Attachments
Fire emission.zip
(2.08 MiB) Downloaded 303 times
BK
OctaneRender Team
Posts: 1440
Joined: Mon Oct 31, 2016 7:54 pm


Thank you BK

I attached the sample scene. If you can tell me a proper max grid value that would be great. You can go to frame 28 of attached sim or resim it again.

Hi Coilbook,

Thank you very much for the file attachments. The grid value we use is 30, can play around 25 to 35.

We have attached the file for your reference. Please try these setting and let us know how it goes.
Attachments
2017-08-03 15_41_12-NVIDIA GeForce Overlay.png
Coilbook.7z
(2.1 MiB) Downloaded 302 times
Kind Regards

bk3d
User avatar
haze
OctaneRender Team
Posts: 1003
Joined: Sun Feb 08, 2015 8:57 pm

I might just add that a physical fire usually does absorb a lot of light. Therefore, you want to make sure you have some absorption, otherwise the scattering spectrum will make sure that the full emissive power of the volume will be scattered towards the camera.

Also, it seems there was a phoenix window with some text in it , something like "Liquid/Temperature ( 300 : 2000)" - it seems that the first number (300) is the max value of temperature. Similar values are there for the other channels. When Christophe gets a chance he said he'll have a look to see if he can auto populate the max value of the ramp with this value from phoenix.
coilbook
Licensed Customer
Posts: 3032
Joined: Mon Mar 24, 2014 2:27 pm

Thank you all! I did not realize how small emission scale should be
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