Blender (2.91) modular tree addon, with particle system the leaves do not show up

Question

I used the modular tree add-on to make trees for a forest scene.

I want to scatter all the trees that I made around my scene via a hair particle system, but whenever I make the particle system, it only scatters the tree part and it doesn't take the leaves with it. In other words, whenever I make the particle system for my trees, the leaves do not show up on the trees. (see image below)

As you can see from the image, the particle system does not render the leaves with the trees. Also, whenever I try to do the "render as collection", nothing even shows up, so I don't know what to do here.

I think it is probably because the leaves are parented to my tree object, and blender's particle system is not programmed to scatter parented objects. Normally that would be ok because I could just join the objects together, but because I used the modular tree addon, the leaves disappear whenever I join them.

The only other solution I have found so far is to convert each branch on the tree's particle system into their own individual meshes and then join them together, but that makes my computer incredibly laggy and I would really prefer not to do that, so if anyone has any creative solutions for this it would be much appreciated.

Answer 1

After I examined the file and the way the addon works, I saw that the leaves are just vertices that emit hair particles. So, when you add a hair particle system to the plane, it just puts the tree trunk on, without the leaves.

After some trying I successfully joined the leaves and the trunk together. What I did is I first added a vertex group, which contained all the vertices that were in the object, emitting the leaves. Then I joined the leaves into the trunk, and then I added the particle system to the new object (since I added the leaves to the trunk, and not the opposite, the particle modifier was gone. I used the same particle system from the drop-down menu). I set the density of the system to appear from the vertex group, so now I had a whole object, emitting hair. but this still wont work, because its still hair.

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The actual resolve

What you need to do is you have to convert all the hair objects into meshes. In the modifiers tab, just click convert. I would advise you to put the leaves object in a collection first, so that its easier to work after.

So, now you will have 3000 objects. Now, you need them all in one mesh. So, select all of them (if you listened to my tip and you putted them in a collection, RMB on it > Select objects), then select the trunk last, so its the active object, and hit Ctrl + J Join Meshes . This is really hard for the computer to work with. Mine cant, actually. One tip, is to look away from the tree when joining, off course in blender, not irl. It makes it easier to actually do the calculations when it doesnt have to display it.

Then, you'll have the tree object. Now, when you put it as hair object, it will show all.

This may not be the best way to do it, but I cant think of another, currently.

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New solution I found

So, I just found a new way to make it, and I even successfully rendered it.

What I did, is I used the tree I made by joining the leaves and the trunk together (See how I did it above). Then I set the hair instance object to be the new tree. So, now, if I convert all the trees into meshes, they will crash blender, because once they are meshes, their particle systems will work - i.e. it will have to show 1000 particle systems. That's why, before converting, disable the particle system on the tree model, so that you don't crash blender. Again, I advise you to use collections, because they make life so much easier.

After this, if you hide all trees except one and then you enable the system, you will see that it looks like a bush- really packed. This is because of the size difference between the instance object and the trees, that came out from the hair. So, first you need to copy the particle system onto that one tree, so that it won't effect the instance one. Then, you can change the size of the leaves, the amount etc.

After you are happy with the result, you can apply these particle settings to all trees. Make sure that before you do this, you hide the system from the viewport, to prevent blender from crashing. Then, you select all trees, then at last you select the one you were working on, Ctrl + L > Link modifiers. Since particle systems are modifiers, by linking them to other objects, you copy the particle systems as well.

And that's it! Now the trees are nice and done. Here is my render (its pretty low quality and its a screenshot, just for show off)

Answer 2

I had a similar problem, when I was adding the trees to my scene as a collection for a particle system, I had no leaves. So first convert your leaves from a particle system by applying the particle modifier to them from the modifier stack. Then (this was the mistake I was missing, so joining wasn't working for me) if you made your tree in sapling-tree or mtree you have to convert it from a vector to a mesh (in object mode with your tree trunk selected, click object, then scroll down to convert to mesh)before you can join the trunk/branches to the leaves (guess you cant join mesh's and vectors together) also by converting your vector tree to a mesh you can get a better texture wrap. Now that both your tree trunk and leaves are all mesh's you can select them all and join them. Now the tree is whole and can be used in a collection for a particle system to add to your landscape. Hope this helps someone it frustrated me for hours! (pro tip in this sequence; if you convert the tree trunk to a mesh 1st, then select the leaves and add the modifier once you apply the modifier, the thousands of leaves are already selected so just "shift left mouse click" the trunk then "Ctrl J" to join them done)