Render Mask and Mesh Light, vray 3.2

[o-v]

Hallo Guys

I'm trying the render mask feature with a mesh light while the camera is animated.

Being precise i choose "selected" in the render mask drop down.

Having issues with it. I'm getting here weird artefacts and completely dislocated renders... In one word: it does not work at all!



Max 2014 file is here:
http://89.26.13.201/pf/Meshlight.rar

I would appreciate any kind of a hint

Thank you very much in advance

Ondrej

PS: one more thing: if I set the intensity of the mesh light to 0. the mesh does not render... literaly, its gone. if set to -1 its pich black - which is as expected. set to 1 - well, the light is on. the intensitiy value has to be an integer, if not: vray crashes, thats not very kind . so how can I render a mask for the vray meshlight? that's what the fuzz is all about. btw. setting a object ID does not have any effect in the multimat element pass = is not rendered. which is actually logical - its a light! but I still need a mask for the mesh. And just one more thing: "extract mesh as node" does not work eather... nothing happens.

[tashko.zashev]

I'm getting different result with your scene here:


Are you rendering in single frame mode or animation sequence ?

[o-v]

Hello...

1) ok I know, it's a local issue here... so have to work it out here.

2) I need a sequence, but the example shot was a single frame... as soon as the camera stops it looks fine... as long as there's movement... it freaks out.

but hey wait: you've selected the plane underneath!!! select the mesh light itself! so point 1) is not veryfied yet.

[tashko.zashev]

I thing I know what is going on.
Most probably the VFB is not cleared at the end of each render and you see the new render on top of the older one. So try to set the Preview render mode to Clear



Edit : A new render result:

[o-v]

thx I'll check it out a soon as possible.

[o-v]

but the question why the "meshlight" does not render when the intensity is at 0, is still interesting... well I guess "screen" by 0 = 0, so nothing to sample... it would be great, when the base mesh would be rendered instead...

I use the meshlight for neons... and if the light is off... well than there's nothing on the wall.. not good.

[tashko.zashev]

When the light (mesh for this specific case) has intensity set to zero, mesh for this light is not created. So the result you get is expected.
Maybe you can use Extract mesh as node feature to convert the mesh light to a regular poly and get the result you want to achieve.
We also tried to reproduce the crash when the light intensity has decimal values, but without success. Which 3DS Max version you are using?

[o-v]

Max 2014. I animated the intensity to simulate the flickering effect... as soon, as the frame hits a non integer value, max crashes...

I tried the extraction -but unfortunately that did not extract anything... in fact, it crashed max... so I didn't work on that any further... I have already a workaround - but its a workaround... I'd prefer to set the intensity to something like 0.01 for turning the light off...

[tashko.zashev]

Thank you for the quick update.

Unfortunately we are not able to replicate the crash here. Have you used any specific animation steps or a different scene than the one you have attached in the previous post? We tried both decimal symbols "," comma and "." dot from the Win region settings, but without success. The mesh light Multiplier is animated from 20 to 0.001 and the entire sequence was rendered without any issues.
Do you get the 3ds Max Crash Error Report dialog? If yes, can you give me the 3ds Max crash dump file (it is called 3dsmax_minidump.dmp in the temp folder).

[fraggle]

As request in other post, a vraylight tube will solve all of this issues!

[o-v]

@fraggle - please elaborate... can't find any "tube" setting for a vray light. but of course, that might be just dumb me...
@tashko: i exported the light in question out of the scene in a new file and set some weird strange values... guess what: it worked! I have no idea, what caused the crash...

bad day.. too hot in the room... not enough sleep... ehhh.. time for an another beer.

[fraggle]

@fraggle - please elaborate... can't find any "tube" setting for a vray light. but of course, that might be just dumb me....

There is none, so won't find it. But that something vray user have been requesting since 2011. So may be one day...

[o-v]

well the mesh light is actually fine... as long as it works and as long you can track down the culprit in case it does not. in my case - its just odd. it can have many reasons... now it works like there was no yesterday...

but having the opportunity being able to render a mask for it - that would be nice.