Vray Lights are killing my render times

[jmottle]

I've posted an image below to a rendering that I am working on. I've only just started but I've discovered that as soon as I add one vray light to this scene the render time jumps from 13min for an 800x800 image to 36 min. The vray light is up light to the upper right of the image.

The light is default settings except I've changed the light to "store with irradiance map" and set to "invisible"

I'm using Vray 1.45.70 so the Sampling is set to 8

Also how do I get the glass that is perpendicular to the camera to not appear so dead and flat. The glass door looks fine, but the side window is aweful. I've only done a few images with Vray so my experience is limited.

[percydaman]

Im sorry but area shadows are slow... no way around that. you can check the box that computes it along with the irradiance map for additional speed, but the quality will be in line with the quality of your irradiance map.

[cpnichols]

Area lights are going to be slow, but you will be much better detail (and possibly shorter rendering time) if you have use the "store with irradiance map" option. of course you have to be using irradiance maps, and should be at least in the "medium" quality range.

Glass may look better if you play with some fog on it a bit. As the angle of insidence gets shorter and the ray crosses more glass, it will tint toward the fog... can be very effective for glass. Plus it will not kill your rendering time (it is not a SSS effect).

[unknown]

what about using a self illuminated plane with a wrapper material on it? Its in the reces so it wont be seen. Im not intirely sure if its quicker than using a vray light.
Maybe an expert could conferm or deny this method, worth a try tho. I have used this approach for lighting internals on external night shots. Its much faster than real lights.

[tom schuelke]

there are also other things to speed up your immage.

-first the glas. did you use fresnel reflections ? this usualy makes glas best. also you could use a very soft bump to make it less computer like.

-which antialiasing did you use ? if you use many glossy reflections, you should also use adaptive subdevison for your rendering. also you should use this, when you dont store your softshadows in the i-map.

did you use lightmap together with irradiancemap ? this seems to be the fastest light simulation technology exept of using lightmap only with less shadow details.

maybe post some screenshots of your materials, lightsettings, and also rendersettings.

best always is to post the whole scene. someone always try´s it out.

Tom

[cpnichols]

what about using a self illuminated plane with a wrapper material on it? Its in the reces so it wont be seen. Im not intirely sure if its quicker than using a vray light.
Maybe an expert could conferm or deny this method, worth a try tho. I have used this approach for lighting internals on external night shots. Its much faster than real lights.

On a close up like this, I would avoid this method, the quality can be pretty bad. For exterior scenes like mentioned I have used this too. Works great at getting hints of light.