Swapniel16 Posted June 16, 2014 Share Posted June 16, 2014 Hello, I am new in houdini and learning on my own. I was trying to emit fire and smoke from a sphere which is moving in Y direction. But after some frames, the container loses the geo and then nothing emits. The container follows the geo for 5 to 6 frames and then lose it.Can anyone please tell me what must be the issue?? Quote Link to comment Share on other sites More sharing options...
mawi Posted June 16, 2014 Share Posted June 16, 2014 Hello, I am new in houdini and learning on my own. I was trying to emit fire and smoke from a sphere which is moving in Y direction. But after some frames, the container loses the geo and then nothing emits. The container follows the geo for 5 to 6 frames and then lose it.Can anyone please tell me what must be the issue?? By default the container size clamps to the initial size. Go to resize_container node -> Max Bounds tab and uncheck clamp to maximum size. Keep in mind that this will alow your container to grow huge. 1 Quote Link to comment Share on other sites More sharing options...
Swapniel16 Posted June 17, 2014 Author Share Posted June 17, 2014 @Mawi:- Hey Thanks a lot!! It worked. Quote Link to comment Share on other sites More sharing options...
old school Posted June 18, 2014 Share Posted June 18, 2014 Instead of unchecking the clamped bounds, just make your initial container bigger to contain the simulation within limits. Quote Link to comment Share on other sites More sharing options...
Swapniel16 Posted June 18, 2014 Author Share Posted June 18, 2014 (edited) @old School: I did that also. But after some frames the container was losing the geo. Even if I unchecked the clamped bounds, it was holding the geo for another 12-13 frames then losing it again. What I finally did was increasing the minimum and maximum substeps to 3. This way the container was holding the geo till the end without unchecking clamped bounds. Edited June 18, 2014 by Swapniel16 Quote Link to comment Share on other sites More sharing options...
Netvudu Posted June 18, 2014 Share Posted June 18, 2014 If the object is moving really fast, sometimes it helps to use the tracking object tab at the resize node so that the center of the container tries to follow the object. You just have to be careful of not losing the smoke trail. Quote Link to comment Share on other sites More sharing options...
old school Posted June 18, 2014 Share Posted June 18, 2014 (edited) In some sims there may be additional fields that can help out with the resize logic. The Gas Resize Fluid Dynamic DOP used to resize the containers can take more than one field to track. In the Reference Field parameter, you can list any number of fields (space delimited) to track and drive the resizing logic, even though the parameter name is singular. Turn on the visualization of the various fields to see if there is another field that would give you better tracking results and add that to the Reference Field parameter list. You can also track the fast moving object with a SOP reference along with the fields. Edited June 18, 2014 by old school Quote Link to comment Share on other sites More sharing options...
Swapniel16 Posted June 18, 2014 Author Share Posted June 18, 2014 If the object is moving really fast, sometimes it helps to use the tracking object tab at the resize node so that the center of the container tries to follow the object. You just have to be careful of not losing the smoke trail. Hey!! This trick also worked. And I didn't lose my smoke trail also. Thanks for the tip. Quote Link to comment Share on other sites More sharing options...
Swapniel16 Posted June 18, 2014 Author Share Posted June 18, 2014 @old School:- I tried using temperature, burn,heat and even fuel, but I guess in this sim, it is not working. But I got it that this is a very useful idea which I will keep in mind and will do some RnD on it. Also this has led me to one another query. In order to make sim faster, I changed the division size from 0.5 to 0.8. By doing this, the container lost the geo in the very next frame only. I checked it by getting back to 0.5, n every thing was fine. So has division size also got to do anything with the tracking?? B'coz in my scene, it surely is affecting the tracking. Quote Link to comment Share on other sites More sharing options...
old school Posted June 23, 2014 Share Posted June 23, 2014 Division size may change the simulation itself for sure. Can this make parts of say the burn field that once had fluid not have fluid? Yep. I did mention tracking the fast object as well as did Netvudu. The best way to track fast moving objects. 1 Quote Link to comment Share on other sites More sharing options...
Swapniel16 Posted June 23, 2014 Author Share Posted June 23, 2014 Thanks a lot to all of you for your valuable replies. My sim is working fine now. This was my first topic in odForce and I really got quick and amazing replies. Quote Link to comment Share on other sites More sharing options...
zaken7 Posted September 15, 2015 Share Posted September 15, 2015 Hi everyone ! Im learning Houdini and i try to achieve a smoke sim too. And i had the same problem as Swapniel16 i tried all the different method and the container keep losing the object. I don't know what to do.... i tried to increase the padding it doesn't help. May anyone explain to me what did i do wrong ! Here my scene filesceneSetup.zip Quote Link to comment Share on other sites More sharing options...
cwalrus Posted October 7, 2015 Share Posted October 7, 2015 Hey Zaken7 - simplifiy your scene tremendously and then re-upload. for example, remove the FBX and ABC refs Quote Link to comment Share on other sites More sharing options...
zaken7 Posted October 29, 2015 Share Posted October 29, 2015 (edited) Hey Zaken7 - simplifiy your scene tremendously and then re-upload. for example, remove the FBX and ABC refs Hi sorry for the delay i was really busy. However i still not figure out how to track fast object in my case. I've set another simple scene file up and this time i've included the object reference. Basically the plane is falling and one of the wings emit fire. I've created a box and parented it to get the motion of the plane Thanks TestFile.zip Edited October 29, 2015 by zaken7 Quote Link to comment Share on other sites More sharing options...
cwalrus Posted March 22, 2016 Share Posted March 22, 2016 Hi Dominic - Don't know if you're still looking for an answer on this one. I took a look at your scene - I had to relink the nodes to the alembic, of course, but assuming you have that done in your scene, it looked pretty good. The only things I changed were the substeps (put the min and max at 10 at least) and the source volume. Try this one, make sure your alembics are linked, and do a flipbook render: S2P13.hipnc 1 Quote Link to comment Share on other sites More sharing options...
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