Corona 1.6, FP 5.3.1/2/3b grass is changing during the production rendering

[Bormax]

Hello. I'm not sure is it the bug of Corona or FP, so I decide to publish this post here and on FP's support forum too.

I use Corona 1.6 and since the Forest Pack 5.3.1 I'm getting pretty weird grass renders. I use Edge option from Boundary checking section and DistanceToEdge effect, and I suppose this problem connected somehow with that. Please, check attached pictures. Three of them saved from the same rendering saved on different render times (you can check the stamp and the names of the pictures contain render time also). As you can see the whole grass is changing during the rendering – material color and the boundary.

I haven't see anything like this ever – object is changing during the production rendering!

I had to install Forest Pack 5.3.0 which works well in my case and I get render result which I supposed to get (picture attached too). Picture saved in the beginning of rendering with FP 5.3.3b is showing the grass as it should be, but longer render is going - worse grass looks...

Any ideas what is this?

Max 2014, Corona 1.6, tested with FP 5.3.1/2/3b

[Bzuco]

I can confirm this issue, or half of this issue. Few days ago I was rendering similar exterior scene with FP grass preset slightly modified in forest color. I am massively using Edge option as you, but without distanceToEdge. During rendering I was changing exposure many times and suddenly grass started to be brighter and brighter. It happens me twice during rendering 21 shots. I can not confirm issue that Edge option stopped working during rendering process and grass goes through the curb, because on my two shots was different angle without visible curb or sidewalk, but probably it is the same issue too.
I simply stopped rendering and hit render button again without this issue. I will also post this to your itoo topic. Probably it will be harder to reproduce...we will see.

I am also using max 2014, corona 1.6, but FP only 5.3.2 version

[Bormax]

I simply stopped rendering and hit render button again without this issue.

Thanks Bzuco!
Unfortunately, in my cases stop/start render didn't help...

[Ondra]

hi,
is the problem solved when you check "lock 3ds max" checkbox in render settings?

[Bormax]

Thank you Ondra for this suggestion! I've made some tests and it works well with ticked "Lock 3ds Max during render".

Few minutes ago I read reply from FP support on their forum - they explained why it happens and now for me it's clear why "Lock 3ds Max during render" helps in this case :)

Thanks for support!

[Ondra]

we were already contacted by Itoo developers and we will try to fix these issues once and for all

[Bormax]

Great! Thank you!

[Ondra]

fixed on Itoo's side AFAIK

[iancamarillo]

I'm having some flickering errors in my animation. Not sure if it's related to this thread but I've uploaded a video with the link below. It looks like it's flickering at the edge (edge mode is on). I'm rendering on 6 computers (windows 10/7) using Max 2018 with backburner. I have not tried the "lock 3ds max" option but I'm not sure that is related to this error? Also, I've cleared the camera and unchecked limit to visibility in FP. I haven't changed the embree settings and I haven't tried converting to instances using forest tools. Thanks
https://we.tl/szHPSXAwcV