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Author Topic: Combining UV channels for distribution mask?  (Read 1424 times)

ZO6039

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Combining UV channels for distribution mask?
« on: April 26, 2023, 09:16:06 PM »
I am trying to start using ForestPack plugin after extensive use of Multiscatter plugin. And I am having a problem to combine masks with different UV channels in ForestPack what worked fine in Multiscatter. For example, I need to combine pattern mask on UV channel 2 which uses Real-World Scale with roads mask on UV channel 1 (see image attached). How can I do this in ForestPack?

Michal Karmazín

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Re: Combining UV channels for distribution mask?
« Reply #1 on: April 27, 2023, 10:26:19 AM »
Hi,

For these purposes, you can use the Composite map (it'll work just fine, even though layers will be mapped with different channels). I hope that helps.

Best regards,

ZO6039

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Re: Combining UV channels for distribution mask?
« Reply #2 on: April 27, 2023, 08:16:42 PM »
Hi,

For these purposes, you can use the Composite map (it'll work just fine, even though layers will be mapped with different channels). I hope that helps.

Best regards,
Composite map is what I tried to use. And it didn't work. Here is the information from documentation:
Image->Map Channel
As alternative of using the X/Y values to define the density of the distribution map, it's possible to get the scale from the UV coordinates of the surface. This mode is useful to adjust the position of trees in more precise way, using a surface map as reference.

To use this mode, a surface object must be assigned in the "Surface" rollout. The Surfaces can work in two operation modes, XY or UV (defined in the Surface rollout):

- XY mode: the UV coordinates are taken from the map channel defined with this parameter.
- UV mode: the map channel 1 is always used, and this parameter is locked.


As I can see from documentation there is only UV channel 1 used. Another problem is when I change surface to UV mode I can't render any instances at all. They do not show up in preview and and they do not render. Some sample scene with using surface in UV mode would be very helpful.

Michal Karmazín

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Re: Combining UV channels for distribution mask?
« Reply #3 on: April 28, 2023, 03:27:46 PM »
Hi,

Thanks for your swift reply. Currently, if you decide to use the UV mode for the Forest distribution, you should have the Channel 1 of the used surface mapped for this purpose, but you can use the Match Color ID on Map feature to “mask” the distribution in the Channel 2 if you assign a black Color ID to a Disabled item. Please find attached a sample scene showing this possible workflow.

Best regards,

ZO6039

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Re: Combining UV channels for distribution mask?
« Reply #4 on: April 28, 2023, 09:12:48 PM »
Thank you for the provided file but it doesn't help much for my needs. The setup is very complicated and I cannot transform it for my purpose. When I try to replace gradient radial map in diversity UV #2 to bitmap (patches1.bmp, for example), and change it to Real-World scale, adjusting UV Map #2 on ground surface as well, this setup doesn't work anymore.

One more time. Tiled pattern bitmap mask for plants distribution (UV channel 2 with Real-World Scale) needs to be combined with roads bitmap mask (UV channel 1).  If this is possible in Forest Pack, please make an example scene, because all my attempts failed. Thank you so much!
« Last Edit: April 28, 2023, 09:18:28 PM by ZO6039 »

Michal Karmazín

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Re: Combining UV channels for distribution mask?
« Reply #5 on: May 02, 2023, 10:37:55 AM »
Hi,

Thanks for your swift reply. I’m afraid, that as mentioned previously: “... if you decide to use the UV mode for the Forest distribution, you should have the Channel 1 of the used surface mapped for this purpose ... ”. At the moment, the main Distribution Map has to use the Channel 1. You can apply a mask in another channel by using for example the advised “Match Color ID on Map ” workaround, but it’s not possible to switch these.

Best regards,

ZO6039

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Re: Combining UV channels for distribution mask?
« Reply #6 on: May 02, 2023, 05:46:40 PM »
Thank you for information. I think, I will have to stay with Multiscatter plugin before I figure out how to use Forest Pack.

ZO6039

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Re: Combining UV channels for distribution mask?
« Reply #7 on: February 09, 2024, 03:35:47 AM »
I started to use Forest Pack but I am still really missing the ability to use a Composite map with the mix of maps with different UV channels as the mask for Distribution map in Forest Pack. What is the problem with that? Why regular 3ds Max map cannot be used for such purpose?

iToo

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Re: Combining UV channels for distribution mask?
« Reply #8 on: February 09, 2024, 12:16:19 PM »
UV Surfaces can use only channel 1, due to the way that surfaces are handled in Forest:

To speed up the scattering process, surfaces are pre-processed in a common cache, storing multiple data including the UVW coordinates.
Since this cache is shared between all Forest objects, initially we don't know what map channels will be neeed (assuming each Forest object may use different channels), so we limited it to map channel 1.

A similar issue occurs with the use of multiple UV channels for the Distribution Map.

No promises, but i'm taking a look to this, and we'll try to remove these limitations.

Carlos Quintero
iToo Software

ZO6039

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Re: Combining UV channels for distribution mask?
« Reply #9 on: February 10, 2024, 01:35:35 AM »
That would be great if we haven't had such limitations. Thank you in advance for looking at this.