Max 2021 Particle view, density material

[robw]

Hi, I use particle flow to place vegetation in a scene all the time.

Like this: Particle View - Position Object - Location - Density by Material - Use sub-material

Then assign a multi material to my ground, where slot 1 is the beauty pass, and any remaining slots are used to place trees, grass, plants on the ground.

Since I updated Max to 2021 recently, this doesn't work.

I could never get it to work by plugging the bitmap into the diffuse slot of a Physical material, or anything for that matter, other than a simple legacy material.

In Max 2020, if I created a new Blend material, Max would auto-populate the two slots with legacy materials. I'd then simply move this to my ground multi-material, add a greyscale image into the diffuse slot for vegetation density, and this-chicken-got-wings, plants where I want them. I'd create 5-10 different materials like this, and then using the sub-material option in particle flow I can adjust the look of the vegetation without hassle.

However, now in Max 2021 this material type doesn't exist anymore and my whole workflow is out the window.

Anyone know how to make it work? - if it made sense 🙂

Thanks

[madsd · Accepted solution]

You need to use the Opacity slot, and you dont need to create blend materials to do this, you can make a custom OSL photoshop like dynamic stacking of control maps for all kinds of things, done shade space, so you only use 1 material and a shader instead of what you normally do with creating materials pr ID, that is not so good IMO, its better to handle it shade space.

Works fine with vertex painting the mask as well, here I use channel 2, first socket .x