hidden light?

[jo-ke]

I would like to render a ceiling with a hidden light.

But what are the right settings?

I have an emitter and an emitter with invisible light.

But this this slows down the rendertime to much. rendering a pano with 6000 x 3000 is impossible and the kerkythea export crushes.

the small render here 800 x 400 tooks 20 minutes in preset lowwithout antialiasing

what are better settings?

[Chris]

How complicated is you emitter mesh? Low/Low+ through High/High+ use a lot of memory and time to render emitter meshes regardless of if they are invisible or not. This doesn't mean you can't use them in that context. But you need to keep them as simple as possible, single triangles or rectangles without holes.
Otherwise, have you tried the Interior/Interior+ render method? It is much more suited for this kind of scene.

[jo-ke]

Emittermesh is very simple

Only 4 rectangles as fake emitter and in front of that invisible emitter also 4 rectangles

Prest low and preset 9 are both taking a long time.

The pano in preset low ist now rendering for 3 hours and still only 50 %

This is too long for my workflow, I have 10 more panos to render

[jo-ke]

still rendering for eleven hours, 60% Antialiasing

[Chris]

Complicated lighting takes more time. There's just no way around that. You can try adding some fill lights behind the camera view; the added light may help with speed.

I don't know what size image you chose to render but 6000x3000 is a huge render and is going to take a long time. The best you can do is follow the standard practices for render speed, which is provide plenty of light and use simple materials.

[jo-ke]

behind the camera is impossible while rendering a pano.

would you prefer preset 9?

first pano is finished, second one is on the way.

I think I have to use some more pcs, each to render one pano on kt.

[Fletch]

If speed matters, do not use any light emitters with Easy 1-7. Instead, make your cove light shining up on the ceiling using many small, evenly spaced spot lights. They will render quite fast in comparison. In my testing, 60 spot lights in a cove will render faster than a single long rectangle.

[Chris]

behind the camera is impossible while rendering a pano.

Right... hadn't thought about that. Hopefully Fletch's suggestion will help out.

[jo-ke]

thank you. I will try that.

nice project is on the way...

[jo-ke]

confusing.

I don't know what happened here.

seems to be one material is wrong, but which one?
something is glowing

Exploration render is OK low an #9 are both impossible to use. result ist like the picture.

Can You help me?