Bug: Lightmapped4way results in weird problems

[THE_Sito-legacy (THE_Sito)]

Hello! New here, but definitely not to mapping. I’ve been mapping for over a decade at this point. I recently returned to Source engine after a long time in UE and it’s been well…challenging. One of the issues I’m facing is with Lightmapped4way materials for displacements. There’s this strange error where, if a displacement is viewed at a certain angle, the fourth texture (ALWAYS the fourth) gets very dark, and turns either brown or a muddy blue. There also looks to be some other texture mapped onto it, I sometimes see striations. I’ve checked the .vmt and couldn’t find anything off about it.

https://imgur.com/a/1dAbO

As you can see, the problem is pretty glaring.

Here is my vmt:

Lightmapped_4WayBlend
{
“$basetexture” “militia_classic/rockblend01”
“$surfaceprop” “rock”
“$texture1_lumstart” “0.0”
“$texture1_lumend” “0.5”

    "$basetexture2"             "militia_classic/sand01"
    "$surfaceprop2"              "sand"
    "$texture2_lumstart"        "0.0"
    "$texture2_lumend"          "0.5"
    "$texture2_blendmode"       "0"
    "$texture2_blendstart"      "0.8"
    "$texture2_blendend"        "0.9"
    "$texture2_uvscale"         "[1.0 1.0]"

    "$basetexture3"             "militia_classic/sand02"
    "$surfaceprop3"              "sand"
    "$texture3_blendmode"       "0"
    "$texture3_uvscale"         "[2.0 2.0]"
    "$texture3_lumstart"        "0.0"
    "$texture3_lumend"          "0.05"
    "$texture3_blendstart"      "0.8"
    "$texture3_blendend"        "1.0"

    "$basetexture4"             "militia_classic/sand03"
    "$surfaceprop4"              "sand"
    "$texture4_blendmode"       "0"
    "$texture4_uvscale"         "[2.0 2.0]"
    "$texture4_lumstart"        "0.0"
    "$texture4_lumend"          "0.2"
    "$texture4_blendstart"      "0.9"
    "$texture4_blendend"        "1.0"

    "$lumblendfactor2"          "0.5"
    "$lumblendfactor3"          "0.7"
    "$lumblendfactor4"          "0.4"
}

Any help is greatly appreciated. I’ll definitely stick around and help whoever I can with their issues. Cheers!

[Grenade_Man-legacy (Grenade Man)]

You seem to have a lot of parameters in your vmt. Maybe remove any non essential lines and test it out to see wether those are causing issues

[THE_Sito-legacy (THE_Sito)]

@Grenade Man

You seem to have a lot of parameters in your vmt. Maybe remove any non essential lines and test it out to see wether those are causing issues

Hey there, I recreated the .vmt using VMT Editor 1.3.9 but the issue persists. I think what I will do as a workaround is to simply use the first three textures and disregard the fourth, blending between three textures is better than just two, I suppose. If I ever find a solution I’ll be sure to post it here.