Artifact along autoshader border

[TokisanGames]

When far away, there's pixelated noise along the border between autoshaded and manually painted areas.

Looks similar to #244 and may be related or have the same cause.

[TokisanGames]

This can be fixed by either removing the overlay shader optimization

if (out_mat.blend > 0.f) { 
to
if (true) {

Or by moving the secondary texture lookups into the main function scope, moving them before the if out_mat.blend>0.

vec4 albedo_ht2 = texture(...)
vec4 normal_rg2 = texture(...);
if (out_mat.blend > 0.f) {

[TokisanGames]

The above workarounds also fixes #244, so this is a duplicate. And both will be fixed with the latter as the branch does seem to still provide some optimization on my 3070.