CUDA Strange erroe when rendering hair

Hi all! I’m trying to render character with my gpu (GT 755M), but I always have an error. I tried reducing hair children (10 worked :frowning: )- I have 1000 strands and 100 childred, character isn’t so complex and you can see poly cound (vievport and render poly counts are the same). I only can render this on CPU, but it’s sooo slow. Also I don’t have any hidden objects or anything like that. It crashes even if I set tile size to 28 for ;( Help!

Looks like a GPU memory issue. Some ideas.

Reboot your computer. Open only blender and try it.

lower the number of segments in the hair.
Lower the display steps of the hair
lower the curve subdivisions

try b-spline
render the hair separately
if you are using gpu experimental for sss, try supported and get rid of your sss.

Still nothing. Only change is error message :confused:
Even with 0 curve subdivisions. B-spline only made it worse :frowning:

Not sure, can you post a simplified blend?

Thank you :slight_smile: It worked when I set timeout to 16 :wink:

Wait. After few tiles blender crashed again with CuctxSynchronize error. Will increasing trdelay value help? And is it safe to change it to 32 (or another number, because it has to be hexadecimal and I’m not sure if 32 is…)?

yes 32 is Hex :slight_smile: it’s 50 in decimal, I haven’t tried other values but I can’t see how it could hurt worst that will happen is you will most likely lock your system up and have to hard start it again so save everything first. If you look at the original post he there is another option you can set to 0 to turn the time out off all together but you might freeze your system and have to hard start it. Saying that don’t hold me responsible if it does break anything it’s your risk to accept :slight_smile:

I’m wondering if there is some bug been introduced with either 2.74 or the latest nvidia drivers I never had the issue before and it’s strange you have it as well and I think they did work on the hair dynamics as part of 2.74, I’ll keep an eye out and see if others start to report issues and get a proper bug report raised if we start to see a lot but there’s not enough to go on as yet I think.