Render Farm TV screen

[Peter Milner]

Normally I create a TV or computer screen by adding a decal to a flat face and then turning it into an area light with "colour by object" selected.

This works well as it allows me to change the brightness of the screen in the editor.

However, this does not work with the Hybrid engine in conjuction with the Render Farm.

It does work with the Hybrid engine on my local machine and with the Path Tracer engine on the Render Farm.

[Roy Hirshkowitz]

Likely another bug-- can you send a small example drawing?

[Peter Milner]

Here you go.

[Roy Hirshkowitz]

The TV in your model isn't working correctly with the Hybrid engine at all-- need to figure this out before looking into what, if any, differences I find on the Farm.  I'll look into it more tomorrow.

[Peter Milner]

That's strange. It works with the Hybrid engine on my local machine.

[Roy Hirshkowitz]

So I think I found the culprit in this particular drawing-- there are actually three objects here.  One is the solid which contains the glass material-- the second is the light source object itself, a region I believe-- the third is a region also tagged with glass material.  I believe the third one is problematic.  The surfaces are probably too close for comfort.  Once I removed the third surface I got the following from the render farm:

For this one I turned off all of the lighting except the TV and turned down the brightness a bit to represent a screen at night.  The results were consistent in the main product.

[Peter Milner]

You need the 3 objects.

The solid is the TV casing only. Then there is one region with the decal and set as the light source. Finally the sheet of glass at the front is for reflection.

If reflective decals worked on the renderfarm, then I could lose the glass.

This one is rendered on my local machine with the glass in place.

[Roy Hirshkowitz]

Well- you should have reflective decals on the farm now-- as long as you've got one of the later builds.

*****

There's still something I don't quite understand, even about your example above.  The background reflection should be a lot brighter-- something's not right.  The sky outside is many times brighter than the walls.

[Peter Milner]

Probably just the angle and balance of light.

Here it is with more realistic settings with both engines.

Hybrid

Path tracer

[George Ioannidis]

Path's looks really convincing to me Peter.

[Roy Hirshkowitz]

There's still definitely a bug in the Hybrid engine here.  When I displace the frame and the glass sheet laterally I get this:

The light source glow behind the glass is not correct-- in fact it's not glowing at all, just receiving light.  I need to take a closer look at this.  Reflective decals probably do work for this, though (haven't checked.)

[Roy Hirshkowitz]

Bug does not require a decal, BTW.  (I have a decent idea what this is.)

[Roy Hirshkowitz]

So I think this one's handled now-- this is a farm generated image which seems to correlate well with the one on my main box.  I used the Channel controls to boost the screen x 20.  Otherwise these are your settings.

I need to verify that I haven't broken sub-surface scattering since that was the code which broke the ability to see emissive surfaces behind glass.

I'll work on the cylindrical decal issue this morning.