Blender fluids to LightWave: a workflow

With the release of blender 3d 2.4 there are some interesting fluid simulation tools. I really know very little about either blender or fluids but I wondered how to go about getting the similation results into Lightwave for rendering or integration into a current scene. Why? RealFlow is US$1200 and blender is free. I’m not saying blender is any competition but for some for simple stuff it could probably do the job.

Check out the SpinQuad forum for more details (registration is required). Hooray for the other folk on there that have taken this workflow and used it to create some great work.

(Posted here for posterity)

In the current release of blender 2.4 there are some interesting fluid simulation tools. I really know very little about either blender or fluids but I wondered how to go about getting the similation results into Lightwave for rendering or integration into a current scene. Why? RealFlow is US$1200 and blender is free. I’m not saying blender is any competition but for some for simple stuff it could probably do the job.

So for anyone at all interested here is (in a very basic way) how I went about it.

1. Whip up your simulation in blender 2.4 (RC1 is the current release at time of writing this.). Tutorial here: http://mediawiki.blender.org/index.p…uid_Simulation

2. Export your simulation to multiple .OBJ files. You’ll need to duplicate and modify an existing export script. A big thanks to elysiun forum guru cambo for this. See here: http://www.elysiun.com/forum/viewtopic.php?t=56824

3. Run your script which will export however many frames in your animation there are.

4. Convert all your OBJ files to LWO. You might also want to rotate your OBJ files -90 degrees. A great Modeler LScript (Batch Edit 2 (MD) can handle this: http://www.interialabs.de/lw/lscript/index.html

5. Create a object replacement list in the following format eg:

#LW Object Replacement List
0
T:\fluids\sim2\anim_obj_0000.lwo
1
T:\fluids\sim2\anim_obj_0001.lwo

There are a few utils that can do the basic listing.
Using a DOS prompt: dir *.lwo /on >dir.txt
Directory Lister: http://freeware.prv.pl/
To get the numbering sequence you could use a spreadsheet.

6. Run LW Layout and load the first object. You might want to parent it to a null so you can move the whole simulation around. Go to Object / Properties / Object Replacement. Select object list and go find the list you created previously.

*There’s a ridiculous LW bug in that when you scrub through the scene the objects in your list won’t appear. It’s only when you create a preview that you’ll see things happening. Hence, FPRIME IS OF NO USE HERE.

It then occured to me that to edit the surface settings for, in my case, 250 objects would be quite boring. Having loaded the first object, get the surface settings right then save a .srf file. Get a util from NextLimit called Surface Replacer here: http://www.nextlimit.com/phpBB2/view…rface+replacer

This util lets your apply a surface to multiple objects. But it will not correctly overwrite your .lwo files so it’s best to send the output to a temporary directory and copy them back over your source files.

Go back to layout and Make Preview. You should see your murky creation come to life.

That’s about it. Have fun.