Edge Mode

[JM2915]

I have been trying to use edge mode a few times in the past and I never could get it to work without flaws.
Everytime there are some elements outside the boundary.

Guess I am doing something wrong.

I attached a very simpe test scene showing the problem.

[Michal Karmazín]

Hi,

Thanks for provided scene. The Pivot Point of your Custom Object "Box001" is located outside of the mesh, so that's producing the "offset effect" (Forest Pack is scattering all items using its pivot point position). To fix that, I would suggest you to adjust the Pivot Point of your Custom Object "Box001" in a following way:

Under the Hierarchy tab - Adjust Pivot select the Affect Pivot Only option and under Alignment select Center to Object.

Best regards,

[JM2915]

Actually I did exactly that before submitting the scene.
Maybe it is because you don't have the clone-plugin installed?

Here is the same scene with the object collapsed to a poly.

[Michal Karmazín]

Hi,

My apologies, I wasn't aware of that (without having Clone modifiers properly applied, there was just box having pivot point offset). Now I see, what you've meant. This behaviour is related to the third Clone modifier with Y Rotation applied.

The Edge Boundary Checking mode is not meant to "slice" the geometry, it's removing elements within one item that are "based out of area used for distribution". So, if there are any "overhanging faces" under one element, (as shown on attached screenshot) these will be fully removed or not, depending if the element is based inside/outside of the distribution area.

It behaves like grass blades in nature - if there is a space enough to growth from, the grass blade vegetate and later could overhang that area. Additionally, this way it doesn't affect overall performance (as massive geometry slicing would require huge additional resources). Hope that clears it up a little bit.

Also, as I can see, there are some black artefacts on your image - to get rid of them, please check the Some key notes about Areas->Boundary Checking->Edge mode post - in case of very high density, many overlapping items could cause those. As adviced in mentioned post, increasing V-Ray's Max transp. levels usually fixes it easily.

Kind regards,

[JM2915]

As a future improvement - I would prefer if elements, that are even in part outside the boundary, are left out completely.

But I can now see what you mean.
Can you clarify what "based inside/outside" exactly means?

I modified my test scene somewhat.
There are some elements that are completely outside the the area, but are still visible.
I cannot exactly understand what is going on there.

[Michal Karmazín]

Hi,

"Can you clarify what "based inside/outside" exactly means?"

The Edge Boundary Checking mode is looking for vertices with lowest Z axis value and evaluate if the position of its centre is placed within the area used for distribution or not.

"There are some elements that are completely outside the the area, but are still visible."

In your case, the Pivot Point for used "Box001" item is "elevated" (the half of your object is under the ground). Therefore, as explained above, these elements appear in your distribution. You can double check, that by moving its Pivot Point to item's minimum, there are no elements "growing outside" of defined area.

I should also add, that Forest Pack recognize elements by its Material IDs. As in your sample scene the box has several material IDs assigned, these faces could be removed "independently". I would suggest you to assign to all faces within one element just one Material ID.

Best regards,

[JM2915]

Ok,  perfect.
That seems to solve it.

Have you considered to handle that "pivot" business automatically within Forest Pack?
It seems a bit odd how you have to manually move the pivot around to make the "edge mode" feature work.