Ambient Occlusion Crash

Hi, I’m a returning blender artist --used to work with it a lot until the interface changed some 5 or 6 years ago, and I just could not take it. Now I’m trying again, and finding it very difficult, but getting there. Been struggling with getting materials to render correctly; they look washed, low contrast and too light, and can’t figure out the problem. But right now I have a bigger problem; I put in hours of work setting up materials and textures and forgot to save; and then I mindlessly hit the Ambient Occlusion button in the display properties panel, and Blender seems crashed. In the task manager, blender.exe and blender-app.exe don’t seem to be using any CPU at all. Is the app dead? Do I have to kill it and lose all the work?, or is there a way to get it back?
TIA

Well, I was about to 3-finger it, and it occurred to me to try CTRL-S from the keyboard. Lo and behold, in the middle of the black screen I got a file save dialog, and after clicking to confirm the filename, the rest of the screen came back to life.

Clouds and silver…
Some OSes have a bad habit of clearing out tmp folder automatically so that after 3-finger reboot there is no trace of Blender’s auto saved files which would otherwise save a day. I set different folder in UserPrefs - Files and usually open newest file in this folder after the (quite rare now) crash.
Do you happen to use linear color space textures btw (“they look washed, low contrast and too light”)? Image - Color Space on Texture tab can tell blender to do the correct thing.

Thanks for the tip; I’ll do that.

Do you happen to use linear color space textures btw (“they look washed, low contrast and too light”)? Image - Color Space on Texture tab can tell blender to do the correct thing.

No, I finally figured out what it was. In the World panel, I had made ambient color white, assuming it was going to be modulated by ambient occlusion and whatnot, but that ambient color seems to just blindly add light at the very end of the processing pipe or something. I’ll keep it black from now on.
The other problem I had, but hadn’t mentioned, is that everything was looking reddish no matter what color it was. Finally I found that somehow in … now I can’t find where it was … There was a setting for override all materials with a particular material that was reddish. Maybe dangerous settings like that should have reddish buttons … :slight_smile:
Now I can’t get texture alpha to show on display or on renders, but I should start a new thread.

Render Layers tab has Material Override per Render Layer. Fine for clay renders to see lights&shadows.