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prometheus
01-01-2018, 05:34 PM
was trying to import blender smoke sims, but I get constant crashes when loading a blender openVDB, maybe they are not compatible...or is it some format required for it to work?
Saved the sim cache as open VDB..but it doesnīt seem to work here.

tischbein3
01-01-2018, 05:38 PM
You need to choose a file wich actually contains data, don't use the first file

prometheus
01-01-2018, 05:39 PM
Edit..
I actually got it to work, think it crashed when I choose a vdb file in the middle of the sequence, but I got it working ..it plays as a sequence, so no itīs up for checking quality etc.

tischbein3
01-01-2018, 05:39 PM
will post a vid on this in the 1001 thread in about half an hour

prometheus
01-01-2018, 05:39 PM
You need to choose a file wich actually contains data, don't use the first file

I did, but see my answer..before your post..I got it to work.

tischbein3
01-01-2018, 05:41 PM
Strange, I got the crashes with the 4kb files at the start of the sims.

prometheus
01-01-2018, 05:51 PM
Strange, I got the crashes with the 4kb files at the start of the sims.

yep..thatīs what I got too, but when choosing others it worked..not sure what it is.

tischbein3
01-02-2018, 07:34 AM
ok after a more close investigation I've send in a bug report.

bazsa73
01-02-2018, 07:39 AM
for me it worked too but yes, you have to choose a file where fire and smoke is already present, I could render on frame

prometheus
01-04-2018, 02:01 PM
Dont forget to set your smoke object in blender to be both fire and smoke ..not just smoke only, so you get the flame channels as well, and in Lightwave.. the openVDB properties, you could use Flame in the emission channel, add a gradient on that channel and make something that looks like a blackbody gradient...
Or enter nodes and add a blackbody, see Lightwave 2018 content samples for openVDB.

Keep in mind if you have scatter channel set to density, it will increase thickness with higher values, and also coverage of smoke, while lower scatter values will bring forth the flame more and less smoke.

Another thing I forgot to enhance here that makes a huge impact, that is the property in the lights panel, where you set volumetric intensity..try and increase that while tweaking volumetric items, or openVDB files, it seems a bit odd that something that is needed to push the volumetrics looks, is located under lights..but maybe itīs logicly best? that value is sort of similar to turbulenceFD illuminate smoke.

http://forums.newtek.com/attachment.php?attachmentid=139177&d=1515099678

Stardust
01-07-2018, 01:23 PM
was trying to import blender smoke sims, but I get constant crashes when loading a blender openVDB, maybe they are not compatible...or is it some format required for it to work?
Saved the sim cache as open VDB..but it doesnīt seem to work here.


Dumb Question... But how do you load an OpenVDB file? I don't seem to be able to find where to do it...

Nevermind... found it.....

I'm just starting to look into OpenVDB, what is better? Blender vs Houdini Vs. TFD?

prometheus
01-07-2018, 01:29 PM
Dumb Question... But how do you load an OpenVDB file? I don't seem to be able to find where to do it...

as the rest of the types it is, add a null, enter itīs properties, Hit "p" and then itīs in the first tab called primitive( horrible overlap of tabs so you can not read what itīs supposed to rea..Until you click on it) bad UI:
anyway, check that tab primitive, there you have a text saying primitive type, from there you can choose if its a volumetric item, or open vdp, itīs in the drop down list under mesh, when that is set ..you three types of menus, not all is required to get it to work, I sugges you pick the second list and load it for the scattering channel.

139268

Ah..and I who just did all that work for printscreen :) never mind, Iīll send you the bill next year.

which one is best? well..we got to seperate which fluid system is the best first, as well as define which one works best with Lightwave as imported openVDB, I am only guessing that Houdini is the most Powerful, while turbulence is the easiest to use, but it seem to be of small significance to use VDB, If you actually have turbulenceFD available for lightwave, it is much easier to tweak the shading in turbulence as well as getting openGL previews, and also re-change the sim to fit other elements in the Lightwave scene, Maybe if you use cinema4d and turbulence within that and dont have lightwave turbulence, and want to bring that in for some reason.

But if you invest in turbulenceFD, do not bother with openVDB for that, itīs really not necessary then.

Houdini is powerful, but it comes with cost and learning..though it has prebuilt the nodeworks to fit within pyro tools.
Blender, doesnīt cost you a dime except for having the patience with learning it or tolerate the UI, I seem to have overcome that threshold and is a bit more comfortable with it,
setting up the shading for smoke is a bit more work than with turbulenceFD I think, since it is nodal and you need to add a lot of various absorbtion, scattering, emission nodes
to get it to render right, at least if you set it up from scratch, that however you do not need to do if you open them as openVDB, then itīs lightwaves volumetric scattering system that takes the channel data from blender and can use that for minor tweaking, you do need to make sure you got both fire and smoke in the smoke flow sim when simulating in blender, only smoke and you will not get the flame channel in to openVDB.

Once in lightwave you need to change the orientation of the null, like 90 heading, and -90 in pitch, that should give you the correct rotation for the smoke.
Beware though, importing openVDB files from blender seems buggy, depending on which file you pick, it may crash and I havenīt figure out which ones to pick to avoid it..it seems different each time, and do not scrub back the timeline to zero when you have a blender openVDB file, it is proned to crash.

prometheus
01-07-2018, 02:00 PM
Never mind the surface, shading and lighting of the plane, just a test object...whatīs cool with blender smoke fluid, I could just weight paint in on the aeroplane the area I wanted to start emitt fire, turbulenceFD can not do that because of lack of weight emission ( reservation for any new updates I do not know about) and Lightwave doesnīt have weight painting natively, If you get 3rd powers layout weight paint, and If lightwave 2018 now allows for weight emission as well as if

Jascha updates turbulenceFD to use that, that would be nice.
Blender also has both fire and smoke openGL, while with turbulence you can only choose one at the time unfortunately.

Colors going to black here without depth in the smoke, and to large initial flames, but it was only some first initial test some time ago.
Also..itīs emission is great to lighten up objects..while in turbulence there seem to be a problem with the firelight.


http://forums.newtek.com/attachment.php?attachmentid=139269&d=1515358781

139269

prometheus
01-18-2018, 01:39 PM
Just tested the openVDB again with 2018.01 update, and importing blender cached fire and smoke simulation files, previously while scrolling the timeline back to zero caused lightwave to crash...this isnīt happening now..so that may have been fixed, I need to try more sim cache files though.

prometheus
01-18-2018, 01:51 PM
and some notes, fire shading often by entering emission channel texture settings and you can set your own gradient color there, for flame, if you select flame for the emission channel, there is one gradient called emission data, that is the one you choose then set some color ramps, but you can also do it as shown in the image, instead of a gradient, you add procedural node editor, enter it and and add the black body radiator node and plug it in, while having VPR active ..tweak your temperature, and also balance that against the emission scale to punch in the fire intensity.

the scattering channel select density...
for illumination of smoke, the assymmetry settings is crucial..often very low levels to get the smoke to be "higlighted" as opposed to evenly lit, also important factor for smoke illumination is the actual volumetric density setting for any light you have in the scene.

For smoke thickness, scattering scale helps, or preferably, enter the channels texture/gradient settings, and select scatter data and adjust gradient to your liking for softer smoke density, or thicker.

Hope some of this help getting started...

http://forums.newtek.com/attachment.php?attachmentid=139572&d=1516308663

prometheus
01-20-2018, 11:02 AM
more investigations in blender smoke sims and openVDB
some settings showcasing the node editor in the emission and scattering channel, here in the scattering channel..I have added the light info and plugged that in to the smoke scattering as well, wether or not that is the proper approach, I honestly do not know.
the emission channel can have single color, or color gradients in standard layer, color gradients in node editor, or using as I did in this case, the black body radiator, punching brightness for fire can either be set in temperature or within the actual emission scale.

To note, to acess black body radiator or the light info, and node editing of the shading, I use the procedural layer, called node editor, and from there you can acess the node ediotr, so I am not using the Main node editor in openVDB for this.

I can tweak this endlessly to get the result I want, the question is if I have time to do that, and what result I really want :)

To note, it renders quite fast, faster than doing cycle rendering and setup with nodes, and seems faster than turbulenceFD, if that has to do with the fact that OPEN vdp uses the new volume intergrator, and turbulenceFD uses the old legacy system, I do not know, or if turbulence has more advanced smoke illumination (partly it may have with multiscattering..but multiscattering also requires recalculation time with every little tweak..so itīs slow)

To the right blender opengl view showcasing OpenGL fire and smoke at the same time( TurbulenceFD needs this by the way) and left showcasing opengl representation of smoke (ticks..can be improved maybe)
And VPR render of the fire and smoke.

http://forums.newtek.com/attachment.php?attachmentid=139627&d=1516471257


139627

prometheus
01-20-2018, 12:22 PM
I think I am on the wrong path here with using light info to plug in to the scatter channel, it really doesnīt seem to have an effect to control, you are probably better off to not use texture editor and fidde with that, but rather just just eh gradient scatter data, one have to be careful and tweak them softly though, since the look changes drasticly and if not set right, it may become uggly with artifacts.