This is an URGENT issue. Sad to see update 2024.2.1 did NOT fix it.
We need to be able to show specific maps in the viewport, and not just the shaded material. This is essential for material creation workflow - we need to be able to preview masks and how UVWmapping affect different maps on different channels, as an example. There were no issues with this prior to v2024.
Issues including, but not limited to:
• Not being able to choose which texture to show in viewport when using Multimap/Multitexture (CoronaMultiMap in my case)
• Same issue when using Composite map
• Sometimes no bitmap at all showing when the same map is applied to different materials (Pre 2024, you could choose which texture to display on which material - that option doesn't exist anymore, and is needed.)
• Incorrect maps showing or incorrect UVW/tiling when using materials other than Max Physical Material (Corona materials for instance.)
• When there is an Output map with Color Map active (it will show the texture with the Color Map applied, but not the base texture. Unless you use an Arnold Standard Surface, in which case Color Map is ignored.)
• No visual feedback is given in the SME about which texture is showing (Previous versions used a red tab to show the map currently showing in viewport.)
There's more... Point is: Everything was fine in Max 2023. Please, please, please release a hotfix that resets the SME back to 2023. Current situation makes material creation almost impossible.
Btw, don't focus so much on trying to render materials in a shaded viewport. All renderers now have real-time feedback, and those are used to actually see what the material looks like. The viewport if only to check UV-mapping and placement of masks etc.