mask for multiple surfaces object

[Pierre]

Hi
I am currently using iToo Forest 9.3.2 with 3ds Max 2026.2.
I would like to distribute grass across two separate mesh objects (rocks), with each object utilizing a different mask for distribution. I am wondering if it is possible to achieve this using a single Forest Pack object, or if it requires creating two separate Forest Pack ?

Thank you for your help.

Best regards,
Pierre

[Michal Karmazín]

Hi Pierre,

Although there’s only one Surface Area, you can disable it and add two Spline Areas to cover those surfaces instead. This way, you can adjust the Distribution Map settings individually for each of them.

I hope this helps.

Best regards,

[Pierre]

Thank you for your reply Michal
Unforntunatly my meshes are overlapping in places. With the method you described, is it possible to limit the distribution of a mask to a specific mesh, perhaps by using an ID?

[Michal Karmazín]

Yes, for these purposes, you can use the Surf. Mat. ID field, which allows you to include only the listed Material ID(s).

Best regards,

[Pierre]

Hi Michal
Thank you for your reply
I am currently working with  Redshift 2026.1.1 ( and Forest Pack 9.3.2.)

I am trying to randomly vary the color of individual grass clumps within a Forest Pack scatter. Since using the built-in Forest Color tool often results in rendering errors with Redshift, I would prefer to use a Redshift map, such as `RS Random Color` or `RS Jitter`. These maps typically accept inputs like Object ID, Name ID, or UserData ID for randomization.

Could you please advise on what type of ID (Object ID, Name ID, or UserData ID) Redshift can extract directly from the Forest Pack instances in 3ds Max to effectively randomize the color?

Thank you for your assistance.
Pierre

[Michal Karmazín]

Hi Pierre,

Using these IDs probably won’t work for your scenario, as I believe they refer to the whole scene object (Object ID / Name ID). To be honest, I’m not sure if or how this could be set up - for render engines without an SDK, such as Redshift and several others, we cannot add support ourselves. Instead, we provide an internal API written in C++ for the 3ds Max SDK, which renderer developers can use to generate instances directly in their engines. Therefore, the implementation of our plugin features depends primarily on the developers of each specific render engine. I would suggest reaching out to them directly or via their forums.

I’m afraid there isn’t much more we can do on our side, although we are happy to collaborate with them if improvements can be made. Thank you for your understanding.

Best regards,