Very slow 3dsmax when making any new object with lots of forests in the scene

[K Gazzard]

Hi there.
I have a scene with many forest objects (56), and at least 30 Forest Sets.
Things are painfully slow when the forests are active, particularly when creating new items, moving things around in the layer stack, duplicating items... every time I make a new object, it takes a long time before I can do anything. When drawing a new spline for example, I make the first click and then have to wait about 20 seconds before I can draw the spline. It's not related to camera visibility options, or number of items within objects, or viewport display.

I have no surfaces set to auto. The issues are resolved if I disable all of the FP objects, which is what I am finding I need to do to edit the file at all - even with everything set to frozen, the issue isn't resolved.
This is not unique to one file - all my projects have many FP objects and I have these slowdowns with all of them, frustrating and time consuming. I have just never got around to submitting it as a bug.

Another issue is that sometimes (Often when I first open the file) if I expand a layer with FP objects on it, it takes a long time to expand.

I downloaded the latest update today (v9.3.2) hoping from the changelog that the issue might be resolved (I read about the FP Sets causing issues with layers) but this hasn't resolved my issue.
I did try and delete all the fp sets out of my file, and this did fix it but I'm not sure if that was just because the FP's were now all broken and missing their geometry.

Any ideas?

[Michal Karmazín]

Hi,

I’m sorry to hear you’re experiencing these issues. Since Forest Pack 9.3.1, a problem where ForestSet triggered a Forest rebuild when modifying layers — even if ForestSet wasn’t using layers — has been fixed. Based on your description alone, it’s difficult to determine what might be causing the issue. Therefore, if possible, please send us your scene so we can review it here. Thanks in advance for any additional details you can share that might help us identify the source of the problem.

Best regards,

[RealViz]

I agree that it would be good to have a slightly more sophisticated "update system" when using multiple FPs. For example, if I draw in one FP that references three other FPs, the whole drawing is slow. Wouldn't it be possible to make the FP so that only the selected FP is updated when drawing, and the others only when the mouse is released (stop painting)? This would speed things up considerably while almost keeping the drawing responsiveness.

[K Gazzard]

Hi,

I’m sorry to hear you’re experiencing these issues. Since Forest Pack 9.3.1, a problem where ForestSet triggered a Forest rebuild when modifying layers — even if ForestSet wasn’t using layers — has been fixed. Based on your description alone, it’s difficult to determine what might be causing the issue. Therefore, if possible, please send us your scene so we can review it here. Thanks in advance for any additional details you can share that might help us identify the source of the problem.

Best regards,

OK, thank you - I have sent the file as requested.

[iToo]

Thanks for the files.

It looks like this issue is related to the 'From Layers' feature being enabled in the object 'ForestSet_spline_CAD_natural_wood'.
This feature is triggering an update of the Forest objects each time a new node is created in the scene, or nodes are manipulated in the layers.

We'll try to improve this. Until then, we recommend to add the objects manually to the ForestSet, instead the layer option.

Additionally, Display->Point-cloud->Global density is set to 600%, which is hitting the viewport performance.
We recommend to lower this value, or alternatively setting the viewport mode for Forest objects to Proxy, which provides the better performance.

[iToo]

I agree that it would be good to have a slightly more sophisticated "update system" when using multiple FPs. For example, if I draw in one FP that references three other FPs, the whole drawing is slow. Wouldn't it be possible to make the FP so that only the selected FP is updated when drawing, and the others only when the mouse is released (stop painting)? This would speed things up considerably while almost keeping the drawing responsiveness.

Unfortunately we are limited by the 3DS Max notification system, which manages the updating process automatically.

[K Gazzard]

Thanks for the files.

It looks like this issue is related to the 'From Layers' feature being enabled in the object 'ForestSet_spline_CAD_natural_wood'.
This feature is triggering an update of the Forest objects each time a new node is created in the scene, or nodes are manipulated in the layers.

We'll try to improve this. Until then, we recommend to add the objects manually to the ForestSet, instead the layer option.

Additionally, Display->Point-cloud->Global density is set to 600%, which is hitting the viewport performance.
We recommend to lower this value, or alternatively setting the viewport mode for Forest objects to Proxy, which provides the better performance.

Thanks for your response. For now, with heavy spline references, I will manually add the objects to FP sets instead of layers. I wasn't aware previously that there was a performance difference. By the way, the point cloud set to 600% was just for the purposes of a previz playblast, I had forgotten to dial it back down before sending you the file. I normally work with these settings much lower or as proxy.

Many thanks for investigating this issue.