[SDK] Problems with alpha painting.[Solved]
In my map I have displacement with alpha paintable texture, so problem is that I can't see changing in hammer, but in-game I can see. Just wondering whats wrong there, anyone know how to fix?
1.What the heck is Source SKD?
2. I dunno what could be causing this, it may have to do with what view mode you're in.
3. About point one, it's Source SDK.
Change your view in the 3D grid (if you haven't already) to 3D textured, or 3D textured shaded.
EDIT: also what texture are you using? Cause I might see if it doesn't work for me either and we can send a bug report to Steam.
You must be in 3D Textured (NOT 3D Textured Shaded.)
Actually, try switching modes. I was having this problem earlier and just solved it. I don't know if it's a graphics card issue, or Hammer, but some blend textures act really screwy in Hammer but are perfect ingame. And Alpha painting has never worked in Hammer, but has ingame.
In my experience 3d Textured mode will work and 3d Textured Shaded will not. Here is one of my maps using the "nature/blendrockdirt_tunnel03b" texture in the various views:
Left: 3d Textures Shaded Polyhgons. Right: 3d Textured Polygons.
http://i52.tinypic.com/zu5ngm.jpg
Here is the final result in Portal 2. (I kept painting a little for emphasis)
http://cloud.steampowered.com/ugc/594690325697150016/6E70B80D038D3772720BCFFFCDAA32A18153A28D/
Edit:
Would you mind testing the texture I used in the screenshots, chickenmobile? Thanks if ya do 
Ahm...I was under the impression alpha painting on displacements has always worked. It has for me at least.
Well, the Source SDK has never given me any problems with it, I can't remember if I've tried it in the Portal 2 Authoring Tools.
Now with 100% more inline comments!
I changed 3D camera view to '3D Textured' and it worked, thanks !
I would stay away from displacements unless they are in places you cannot place portals near because there is a known bug with physic objects, portals and displacements.