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How to use the small campfire from EmberGen in DS?

yuyu.atemyuyu.atem Posts: 334
edited November 28 in New Users

Hi! I would like to create a campfire with the VDB effect of DS, and I found this tutorial: https://www.youtube.com/watch?v=YklwvirfKWI.

While I am using the same vb file as Jay uses in the tutorial, everything looks ok, but I also tried with the free small camfire vdb files from emberGen: https://jangafx.com/software/embergen/download/free-vdb-animations.

I followed Jay's tutoral until around 28:20, while he's using the first vdb of its tutorial, and I just changed the vdb file by one of the small campfire's file, but nothing happenned: it looks like there was no vdb file at all on the render... I tried with dofférent frames frm the EmberGen's small campfire, but noone worked.

More precisemy, here is what I obtain with the same vdb file as Jay used:

And here is what i obtain when I just change the vdb file into one of the small campfire:

Do you know how to make it work, please?

Sorry, I wanted to make a video to show you what happen, but for some reason, the render doesn't appear on my video...

Thank you in advance for your help, i hope my explanation aren't too unclear...

Post edited by yuyu.atem on

Comments

  • GordigGordig Posts: 10,102

    I only briefly dabbled with EmberGen, but one thing to look for is the naming of the fields. For example, one program might call smoke smoke, while another calls it density. 

  • crosswindcrosswind Posts: 7,225

    Check the README.txt file within the VBD package to see the VDB channels that are supported. Usually try setting density in both Volumn and Emission channels when using files from jangafx. Then tweak the surface settings and add some light sources as needed ~~

    SNAG-2024-11-29-002.png
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  • yuyu.atemyuyu.atem Posts: 334

    Hi, thank you very much! Maybe I mised something, but I thought having used the same settings as yours, and it still doesn't work:

      

    Can you see what I did wrong, please? Thank you in advance!

  • GordigGordig Posts: 10,102

    You've got "clip to volume" set to On, and I don't know if this step is still necessary, but Crosswind renamed the default surface to "Volume". 

  • yuyu.atemyuyu.atem Posts: 334

    Thank you very much! I just swich "clip to volume" to off, but it still doesn't work... crying How can I renamed the default surface, please? I tried both double clicking and right clicking, but it doesn't look like if I could rename it...

    Thank you in advance!

  • GordigGordig Posts: 10,102

    You do that in the Geometry Editor. Hit alt+shift+G and enter the Tool Settings pane. 

  • crosswindcrosswind Posts: 7,225

    In Jay's tutorial you linked, at the position 19:30... he showed how to rename the surface. cool

  • yuyu.atemyuyu.atem Posts: 334

    Oh, yes, I didn't realize! I was foccus on the first part with the first vdb file Jay used, so I completly forgot this part...

    However, when I do that, it become all black on the render; is it normal?

     

    I don't know if it can be due to that, but when I wanted to change the emission volume channel into "density", there was only the "temperature" opption. I don't know how this channel works, so maybe it is just normal, but I thounght that there would be several options and that I would have to choose one... So what I did here is renaming it "density" instead of "temperature". Is it what I had to do?

     

    I don't know what mistake I did, so in case it would be helpful, I share you the DS file on workupload:

    https://workupload.com/file/DVyNcrdCEtX

    Thank you in advance for your help!

  • crosswindcrosswind Posts: 7,225
    edited December 1

    There're a couple of issues in your scene:

    1) The value (350) set in Emission Temperature Mult is too low (the value in my screenshot was elliptical...), set it to 35000. Then better increase the value in Density Multiplier to > 1000.

    2) The spotlight has a very low value in Lumen (default 1500)... set it to 250K.

    Edit: I don't think that VDB supports channel of "temperature", using "density" is well enough.

    SNAG-2024-12-1-014.png
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    SNAG-2024-12-1-015.png
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    Post edited by crosswind on
  • yuyu.atemyuyu.atem Posts: 334

    Thank you very much! Now, I have the beginning of sometings, but it still doesn't look like yours:

    I suppose I missed someting again... Here is my new file: https://workupload.com/file/EpwqNueQE2X

    Thank you in advance for your help!

  • crosswindcrosswind Posts: 7,225

    Ahh.... you didn't point the spotlight to the file... Change the value in X Rotate of the spotlight to 20.

    SNAG-2024-12-1-016.png
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  • yuyu.atemyuyu.atem Posts: 334

    Oh, yes, it perfectly works, now, thank you very much! laugh I found difficult to point precisely the light to the fire just by moving the light by hands, and searching which orientation is the best... Is there a way to oblige the light to point automatically to the fire?

  • crosswindcrosswind Posts: 7,225

    I don't think Point At is easy to use in your case... but I'd like to suggest use a Point Light instead of a Spotlight.

  • yuyu.atemyuyu.atem Posts: 334

    Ah, ok, thank you very much! However, I notice that when I used the same lumens value for the soplight and the point light, the fire has not the same intensity, is it normal?

    Thank you in advance!

  • felisfelis Posts: 4,457

    Lumen is the light amount and area, so the larger area the less energi in each direction.

    Therefore a pointlight compared to a spotlight with same lumen will be seen as weaker in the direction where the spotlight points.

  • yuyu.atemyuyu.atem Posts: 334

    Ah, ok, thank you very much! I have another question about positionning the fire in the scene. I mean, the fire is quite out of the sphere, so I find difficult to position the fire itself by moving the sphere in the scene, for exemple, if I want to set the fire above campire's wood or under a pot for cooking, etc... So, I wonder if it would be possible to make the fire closer from the sphere, in order to move and position it easier.

    Furthermore, once I will found a correct position regarding other objects, for exemple, if the fire is under a pot, is there a way to make them to keep the same "relative" position if I move one of them? I mean, if I am satisfied on the position of the fire regarding the pot, but I want to move the set fire + pot together, am I obliged to select both of them and move them together, or is it possible to oblige one of them to "follow" the other one if I move it? (Sorry, I don't know if my question is understandible...)

    Thank you in advance!

  • felisfelis Posts: 4,457

    For your first question I don't know if there is options. I have only used VDBs limited.

    For you second question you can parent the fire to the e.g. pot, and then move the pot around. You can either parent both to a 3rd object and then move that around. After parenting be carefull not to translate the children. You can e.g. lock translations for children.

  • yuyu.atemyuyu.atem Posts: 334

    Ah, ok, thank you very much!

    Last question (I hope): for now I am using only one frame from the EmberGen's small campfire, that contains 200 frames. So I wonder how to do to use all these frames and create a video. I never did any video with DS; from what I understood, there is a "timeline" ("timebar"? I am not sure what is the word) that allows to choose which frame I am working on, but I don't know how it works, and above all, I guess that it should be an easier way than setting the campfire frames one by one... Is there a way to insert all the campfire frames together and make "automatically" a video?

    Thank you in advance!

  • felisfelis Posts: 4,457

    It was apparently not so straight-forward. It might have changed - I don't know.

    Try to look at this

  • yuyu.atemyuyu.atem Posts: 334

    Ok, I will try, thank you very much!

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