Rendering fire

[XavBo]

Hi guys,

I was trying something new and I couldn't find how to render the fire like it shows in MaYa in the viewport.

I have a dome light with a HDRI images and a vRay sun light and nothing change.
As you can see in the viewport looks like should be.
In the render looks way to flat.

I already try to change the light situation in the PFD simulation under:
PFD Simulator
Rendering > Fire Lights

I have also GI active in the rendering settings.
But nothing helps me to have the awesome result that I see in the viewport.

Do you have any idea how to solve this?

BTW if I use a vRay Sky looks terrible.

[Svetlin.Nikolov]

Hey,

It would be very helpful if you screenshot and post your fire and smoke render settings.

The GPU preview in the viewport acts like all the lights you have connected in the preview lights set are directional, pointed towards the origin of the grid. If you have no lights in the preview lights set, a default directional light will be created.

Also, it's important to note that if you are not in Viewport 2, the GPU preview in Maya would not be quite accurate.

Cheers!

[XavBo]

Hi Svetlin!
Sure!

I will share with you screen shots.


EDIT:
Well Im using view port 2 and a vRay Sun and Sky light.
I also had a HDRI Image, but that didnt work also.

[thhvfx]

Hi XavBo,

You may need to play around with the fire and smoke shader. It took me a while to get the fire look right. Also if you want to reduce the render time, try to lower your max sample like 4 or 5. I turn off GI in Vray render setiing. GI doesn't really affect much on the fire overall. You can try to turn on and off to see the differences.

[XavBo]

Hi thhvfx!
Thank you for reply.
I will try now.

I already tweak the shader and that is what I see in the viewport.
But I dont know why in the render is way to different.

[XavBo]

Ok!
Now I know why this didnt work.
http://www.class-a-strak.com/...Ball___006.PNG


Actually what do you see in the viewport in MaYa 2.0 is a 85% what you suppose to see in your render.
One thing that doesnt work (at least on fire FX) is activating the GI in the Render Settings.

- But now I have another question.
How to solve the problem on the second 00:12?
Please have a look in the video linked below.
Video name:
Dynamic Box scaling problem

As you can see the smoke get cut from the dynamic scaling box.
Do you know how to get rid of it?

You can have a look into the video below:


- Does PFD support GPU?
http://www.class-a-strak.com/...ion___sent.PNG

After the render finalized I dont get any final render-preview at all.

[Guest]

1. Set the adaptive grid to be based on Smoke (Grid --> Adaptive grid --> Smoke) and set a low threshold.
2. Set the adaptive grid to be based on Temperature (Grid --> Adaptive grid --> Temeperature) and set a low temperature value (depends on the lowest temperature of the simulation). Note that 300 is equivalent to a room temperature.

[XavBo]

1. Set the adaptive grid to be based on Smoke (Grid --> Adaptive grid --> Smoke) and set a low threshold.
2. Set the adaptive grid to be based on Temperature (Grid --> Adaptive grid --> Temeperature) and set a low temperature value (depends on the lowest temperature of the simulation). Note that 300 is equivalent to a room temperature.

Thank you again George.
Somehow the smoke didn't work at the moment.
I will try later again.

Did you had the opportunity to check my message her:
https://forums.chaosgroup.com/forum/...-gravity/page2

Unfortunately I the simulation Steps from the PFD still over the viewport text.
Or should I install the nightly builds?

[Guest]

There is an option in the latest nightly builds called Expand and Don't Shrink (in Grid roll-out menu). Should work for you.

[Svetlin.Nikolov]

Unfortunately I the simulation Steps from the PFD still over the viewport text.
Or should I install the nightly builds?

Yup, the fix is in the nightly builds.

[thhvfx]

Hi XavBo,

For the sim with fire and smoke together I usually set adaptive grid to smoke and set the value to 0.001 . Also from your screenshot I see you are using progressive. I recommend you use bucket and set your Max sub div to 5 and threshold to 0.010 for fast rendering. I actually use this setting for production as well. Really fast and still keep enough the detail. Let me know if you have something better. Hope that will help

Cheers,

[XavBo]

Yup, the fix is in the nightly builds.

Thank you for your fast support.
I already install the latest nightly builds and is perfect working.

You guys are rock!

Hi XavBo,

For the sim with fire and smoke together I usually set adaptive grid to smoke and set the value to 0.001 . Also from your screenshot I see you are using progressive. I recommend you use bucket and set your Max sub div to 5 and threshold to 0.010 for fast rendering. I actually use this setting for production as well. Really fast and still keep enough the detail. Let me know if you have something better. Hope that will help

Cheers,

Hi thhvfx!
Awesome. Let me try tomorrow and I will post a couple of screenshots.

I recommend you use bucket and set your Max sub div to 5 and threshold to 0.010 for fast rendering

Yes I do also that, but I wanted to go high and standard so I can see how long takes the maximum to have a nice result.
I was testing / Im testing also render time.

But is great to point on that so I can remember to bring back to those values.

BTW
I tried also this:
adaptive grid to smoke and set the value to 0.001
But somehow didnt work.

I will try again tomorrow. I did many changes that I dont remember all the changes I did.

I tried also the settings from George and didnt work for me.
Maybe I forgot something.

I will try again.

[thhvfx]

Hi XavBo,

For the fire sim in my personal opinion it all come down to your resolution of the sim and your Phoenixfd shader. Increase the rendering subdiv to 24 or even 100 will not make your fire look better much.

I already tried that and please correct me if I'm wrong. I tested with many setting and I find that's the best so far between balancing the quality and render time.

Let say if you are happy with the shader you can try to change the Self shadowing(Rendering rollout >> Fire Light>>Self shadowing) from Grid based to Ray traced to get even more realistic result but this will increase the render time and I think this is what you want to play with; not the Subdiv from Vray render setting.

Adjust Light Power on Scene to control how much you want the fire light affect to the environment around the fire

Adjust Light Power on Self to control how much light spreading on the fire and smoke itself. Works great when you want the fire affect to the smoke.

For the "adaptive grid to smoke and set the value to 0.001" not working. Make sure your boundary is open in X Y Z. Adaptive grid to Smoke and Preallocate Memory to When Adaptive. Please make sure your source emitting the smoke.

Again this is all my personal experience when I work with Phoenixfd.

Try it and let me know if that works.

Cheers,

[XavBo]

Hi XavBo,

For the fire sim in my personal opinion it all come down to your resolution of the sim and your Phoenixfd shader. Increase the rendering subdiv to 24 or even 100 will not make your fire look better much.

Hi thhvfx!
I did a test and your right!
with a subD of 5 is almost the same result in less render time.

Hi XavBo,

Let say if you are happy with the shader you can try to change the Self shadowing(Rendering rollout >> Fire Light>>Self shadowing) from Grid based to Ray traced to get even more realistic result but this will increase the render time and I think this is what you want to play with; not the Subdiv from Vray render setting.

WOW! Well this increase the time drastically.
Using the Ray traced for the Self shadowing this increase the render time and change the looking for the fire. Looks much more realistic, but for fast and no macro-close up animation - I think this will be too much.
In case I need it - now I know where to add a touch of details
Thank you for that one too.

Hi XavBo,

For the "adaptive grid to smoke and set the value to 0.001" not working. Make sure your boundary is open in X Y Z. Adaptive grid to Smoke and Preallocate Memory to When Adaptive. Please make sure your source emitting the smoke.

For the adactive grid/smoke and with a value of 0.001 until now doesnt work at all.
My all 3 XYZ grids are open.
I tried all the settings possible even the tip from George Barzinski Expand and Don't Shrink and for me didnt work.
The simulation will never expand.


Thank you guys for the great and awesome support.

[Guest]

Hey XavBo,

would you send us the scene to check what's wrong? Meanwhile, you can try Extra Margin grid option