bug with pyro and smoke lighting in the scene view

Forums Technical Discussion bug with pyro and smoke lighting in the scene view

8152 15 1


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 9, 2016 2:20 a.m.

Hi,

We are using Houdini 15 at work and we have noticed that with Hoduini 15 there are some issues with lighting the scene and viewing smoke. We do not render smoke in Houdini and I don't think that there is anything wrong with the render but in the viewport sometimes smoke looks black and if exposure and intensity is adjusted for the smoke other objects in the scene will be blown up. We cannot get both smoke and other Geos lit at the same time nicely in Houdini viewport.
Any help and tips will be appreciated
by the way I noticed this weird bug today that parts of the smoke which was facing the poin lights were black and back of the smoke was fully bright. Didn't matter how much I moved the lights around. restarted a new sceneview with no luck.
Also turning off atuniation does not help. Still can't get both smoke and other Geos nicely lit for flipbook.

Honey


Enivob: Member; 2538 posts; Joined: June 2008; Offline

Dec. 9, 2016 4:48 p.m.

Can you post your machine specs? Perhaps your display does not meet minimum requirements?

Press the D-KEY while the mouse is over the 3D viewport to bring p the Display Options. Under the Effects tab make sure HDR Rendering is turned on. Poke around, there are also some other settings related to volumes that might not be enabled. Save settings and then close and re-open Houdini to test your scene again.

Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 13, 2016 12:48 p.m.

HDR Rendering is on. I checked all the settings. No luck
Machine spec is windows 10 64 bit
processor core i7 5820K cpu 3.3
nVidia Geforce GTX 1070 driver 21.21.13.7270


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 13, 2016 12:51 p.m.

I found this page and I assume this is the same issue
https://www.sidefx.com/forum/topic/42071/?page=1#post-190789 [sidefx.com]


Enivob: Member; 2538 posts; Joined: June 2008; Offline

Dec. 14, 2016 9:16 a.m.

If you are rendering in another package, that package lights may not be optimized for viewport display. Try adding a standard Mantra AreaLight to your scene, above the pyro, and observe the viewport. Also, make sure you have not altered the settings on the pyro_import or the pyro visualization toggles. Both of these nodes control how the result is displayed in the viewport and or rendered.

Which 3rd party rendering package are you using?

Edited by Enivob - Dec. 14, 2016 10:01:38

Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 14, 2016 4:38 p.m.

I am using standard Houdini point lights. and in the pyrovis node I am not changing things much. I never had this issue with houdini 14. It's something new in Houdini 15. I try to see if I can post a picture without breaking the copyright law.


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 14, 2016 6:21 p.m.

ok. both pics are 2 point lights. First picture attenuation is on and I can see smoke looks good enough but the scene is pretty dark( I had to hid all geos from the scene because of copyright but I put down a sphere to make it more clear)
Second image I turned off attenuation and as a result I had to turn down the density but that screws up my volume. Once it become pure white once it becomes pure black.

Edited by honey_khadem - Dec. 14, 2016 18:22:36

Attachments:
smoke1.JPG (242.0 KB)
smoke2.JPG (239.9 KB)


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 14, 2016 6:27 p.m.

smoke3 is just a distance light and you can see how buggy it is to get all abject working in the scene.

Attachments:
smoke3.JPG (277.5 KB)


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 14, 2016 6:28 p.m.

any help is appreciated.


Enivob: Member; 2538 posts; Joined: June 2008; Offline

Dec. 16, 2016 9:52 a.m.

When you say you turned down density, how did you do that? Are you using the remap features of the pyro node?

I would not turn off light attenuation, instead just turn down light intensity. When you remove attenuation from the equation you are essentially in ‘fantasy’ light mode from the 1980s.

I tried recreating your scene, but it seems to work fine in my nVidia 660GTX viewport running Houdini 15.5.

In my experience, it is not really worth tuning the viewport to some ideal look. Instead spend your time tuning the final render.

Edited by Enivob - Dec. 16, 2016 09:55:03

Attachments:
Untitled-1.jpg (81.6 KB)
ap_smoke_viewport_test.hipnc (713.7 KB)

Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 20, 2016 3:18 p.m.

we don't show renders to director for approval. It's just flipbook and they judge based off of that. Also FX doesn't render volumes here. We pass vdb to lighting. Therefore It's important for me to have a good representation of my elements in viewport in order to get approved

I'll try what you mentioned and will let you know the result. By the way why not turning off attenuation when light is used as a distance light like sun. We don't really expect to see too visible attenuation from sun. Am I correct?


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 20, 2016 3:20 p.m.

by the way I know that with a simple and small pyro the chances of getting faulty lighting is less. It usually happens when the pyro is heavy in size and it's too much smoke in the scene.


Enivob: Member; 2538 posts; Joined: June 2008; Offline

Dec. 21, 2016 9:55 a.m.

Try turning off Use OpenCL on the Pyro solver. I find when I try to leverage OpenCL and very fine density simulations that I get OpenCL errors in the console. Which is too bad, you really need the acceleration on larger sims.

The Sun lamp has no Attenuation settings, they are all greyed out.

I tried to recreate your issue on my machine with a 1070GTX but it seems to work just fine. I used a division size of 0.008 with a single area light. What division size are you using?

You could always try writing out a single frame from your simulation and then bring that back into a new Houdini scene and light it. This would be one way to eliminate the possibility that the simulation is some how clobbering VRAM data.

I notice your 1070 driver version is very different from mine. Are you using a laptop?

Edited by Enivob - Dec. 21, 2016 09:56:52

Attachments:
Untitled-1.jpg (60.6 KB)

Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.


honey_khadem: Member; 14 posts; Joined: Sept. 2014; Offline

Dec. 21, 2016 12:32 p.m.

no we have desktops at work. Houdini version is 15.0.244.16
Ok I try what you said and will let you know the result.


malexander: Staff; 5161 posts; Joined: July 2005; Offline

Dec. 21, 2016 8:13 p.m.

You might want to check your that HDR Rendering (Effects tab) and 16b 3D Textures (Texture tab) are both on in the Display Options.


Enivob: Member; 2538 posts; Joined: June 2008; Offline

Dec. 22, 2016 9:42 a.m.

Oh, you are still using 15.0. Go ahead and upgrade to 15.5. Use the latest version of Houdini, if possible.

Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.

Quick Links

                    
                        Search links
                        Show recent posts
                        Show unanswered posts