Why is vertex masking so poorly documented, no decent tutorials

[prometheus]

Hi there, Ivé been googling around, looking on youtube, checking the documentations, trying myself with various vertex maps on both fbx, and obj formats, but I just can´t get the masking of fluid emission working.

I noticed Jason Key had a vid demonstrating “some of it” but that is an older version, he´s not showing exactly the setup for how to connect the nodes, and other things that may be important.

This is to me a very Key element to work with embergen properly …and I am a bit baffled it isn´t covered in documentation or a short intro, specificly defined as vertex mapping emission.

Maybe I approached it wrong trying to just mask out the emission on one single emitter and mask, perhaps two emitters is needed…I just don´t know.

There´s a possibility I missed a tutorial, but there´s so many of them and if I only knew where this may be covered, that would of course help.

Basics, take a toroid apply vertex map on half on it, and in embergen set the mask to emitt only from that, simple things you may think.

/Michael

[prometheus]

Bumping this one,
No one seem to be able to answer on it, or another users question on this matter, I´ve been trying for months (from time to time) with the masks in embergen, just guessing it could use blender painted vertex maps, or weightmaps , can´t find a single video tutorial on it that indicates there is some showcase on it in the video.

It´s the very basics…in blender 2,79, I can paint in a weightmap on a head for instance, use that as emission for the fluids inside of blender with its fire and smoke fluids, dead easy and great.
Now surely it must be a way to use either a Weightmap, or vertex map on One single mesh as the fluid emission inside of embergen, I don´t expect embergen to have a brush paint tool in there at this stage, but surely the ability to emitt from painted weightmaps, or vertex maps only.

Now I have mostly tested on fbx exports, but also alembic, no difference.
Ivé managed to get a fluid emission on for instance two seperate spheres in the same fbx, but I don´t think that had to do with the actual paint I did.

My question was made in december 21, still no one responding with a yes or no, or anything at all, and same with this guys question…

Blender Alembic Vertex Color - Software Support & Suggestions / EmberGen - JangaFX Software Forum

[prometheus]

I have now solved this issue, unless someone makes a tutorial, I will when I am up for it.
Vertex paint masking Is working from blender.

[Juan]

How have you solved this?

I’m in the same problem I have to do a gradual emission over a mesh and there seem to be no way of doing it!

[notwillclarke]

Hi Juan and Prometheus,

So sorry for not getting to this earlier. When exporting vertex maps from Blender, you need to paint the entire mesh black first, and then add your vertex colors. For some reason the default vertex color is white, which is 1 for each RGB value.

Additionally Blender does not export vertex maps properly on Alembic files, so even though we are able to use vertex paint on alembic files, Blender makes that impossible to use.

Let me know if this helps!

[Juan]

Yes, it worked with OBJ.

Do you support USD?

USD implementation in Blender 4.0 is coming and its pretty good, better than Alembic in general.

[notwillclarke]

We do not support USD but we have talked about it more and more frequently over the year. Nothing planned atm but if demand increases we will find a solution

[gordo]

I recently started with Emergen and prior to opening it myself I was at a medium vfx studio using it, and would read the group messages and I saw this was the most common asked question actually.

I am bumping this because this was first brought up in Dec '21… I assumed there was a solid answer and documentation; neither, and a hunt to find THE first thing I am starting with Embergen to do. I still don’t have a solution 6 hours in digging, FBX, ABC, different settings… different softwares…

Maybe I am missing something, but this should def be documented better with simple examples. Preferably alembics over FBX as is just easier and more commonly used format. I would even provide it.

These types of things are more so just disappointing, when you have such fantastic software in a place when this is probably the number one solution to bringing down budgets, but simple import masks is a ?? and mixed info…

[notwillclarke]

the vertex paint workflow is pretty intuitive, do you have any specific questions you have? or a specific software that you’re working from?

[prometheus]

As I mentioned before in june 2022, I found how to get it working, after that I had some computer crashes, and right now I am just too busy with other stuff unfortunately.

So …no tutorial for a while from me anyway.
I would suggest, encourage the JangaFX team to make a tutorial on this little topic specificly though.
I think it is very much needed, unless someone has it within other tutorials perhaps.

Blender is a good start for pretty much everyone, at least for FBX, for alembic…perhaps not as notwillclark mentions below…

@notwillclarke

When exporting vertex maps from Blender, you need to paint the entire mesh black first, and then add your vertex colors. For some reason the default vertex color is white, which is 1 for each RGB value.

Additionally Blender does not export vertex maps properly on Alembic files, so even though we are able to use vertex paint on alembic files, Blender makes that impossible to us

Embergen & Lightning inside a cloud

[prometheus]

Back to testing it again.
In fact, you do not need to paint the mesh black.
In blenders object data properties, you have of course the vertex groups menu, (not needed)
go to color attributes, add a map, use the defaults, it should be set to black color.
Now when that map is added, and you go to vertex paint ( not weight paint)
the mesh should now be black.
Set the color to mix, and switch to rgb mode, turn down all other colors, red, green to zero and for the blue color for instance, a value of 1.

Start to paint, make sure your mesh is divided enought to get smoother edges when finally using it as the fluid shape emission.

save to fbx, once in embergen, you just use the mask 3 (which by default is set tovertex color blue)
run the simulation and it should work…hopefully, but just use the asset import nodes mask output, not the animated geometry output, feed it in to the emitters shapes input.

This way you can paint in a “fake” density map, since it´s a masked shape.
You can for instance paint over a plane grid in blender with a 3d texture set in the brush, and make sure you go to the main texture tabs and use the cloud textures, start paint over the plane grid and the texture will be painted in, this will give you a static cloud map to use as the emission source.

Now…we could really use a true density channel in the emitter tab instead of shapes or forces, any fractal noise we do have now do not work as a density map solely, it also affects the entire force affecting the fluid, so that I wish we could have, we do have this function in blender and lightwave for instance.
Also…more fractal noises are needed, the one we have isn´t very useful for cloud density emission, especially since we can not adjust it without affecting the whole fluid movement.

Also nice if we could load in a png image to plug in to such density channel, and also animated sequences, this would allow for flow maps of any type of image sequenced generation.

Some settings…

[prometheus]

And finally, after one and a half hour, I got it working with vertex color maps in Lightwave as well.
A bit messy though, in lightwave you have to use the legacy opengl for the vertex color paint to show up, and exporting from modeler fbx seem to not work properly, so send to layout and export the fbx with the latest file format from there, that should do the trick.

I need to record all this I guess, soon…it should help both blender and Lightwave users.
I should be able to convert any of the 80 fractal noise type maps to a color map in Lightwave, which will give me by far more fractal types to use as fluid masks than I can get from blender.