VrayBlendMtl alpha not working

[Terri Brown]

Hi guys,

 

I keep on having this issue when using vray blend material to apply a logo or decal to a surface. The concept in this case is very simple - I have created a texture for the brick wall, and on one wall I want to place the decal 'The Shed', and on the other wall the decal 'Bridge'. Both walls use the same base brick material, and I have appled two separate vrayblendmtls (one to each wall). One has a white paint material as the coat with the alpha as the logo, and the other a black paint material with the alpha 'Bridge'. you can see it in the material layout attached. However, I always seem to get a square around the coat material, as if the black of the alpha isn't fully black (which it is). The masks are not tiled as I obviously dont want a repeat of the logo on the wall.

 

In both cases the wall is UV mapped with ID 1, and the decals with ID 2.

 

(Please excuse the rubbish renders - just quick tests for explanation's sake )

[Larissa Holderness]

I have had similar issues with this as well ... would like to know what the solution is. So, bump.

[Scott Schroeder]

Even though you have the blend amount set to 100%, you still need to set your blend color to full black (0,0,0)

 

The image below illustrates this. The base wall should be dark purple, and the graphic (w/grime multiplied in the vraycomp text similar to yours) should be white. If you leave the blend color at 128 gray, your wall is still affected by the coat layer even though the graphic has a pure black and white alpha being used in the mask texture slot.

 

[Terri Brown]

Scott thank u! That's great