Hi all,
on the latest non-beta build of vray… I have a project that has a detailed cornice, though it runs in very straight lines too..
this is part of an animation so I am trying to get an acceptable irradiance map that will not show noise. I am not storing the lights to the Irradiance map,
anyone got any ideas as to how I can smooth out the corniced ceiling detail (see attached)
BTW.. I am trying to avoid BF and detail enhancement at this stage, in order to get rendertimes for the animation to an acceptable level.. might be a region render of the roof at this rate though!
Hi,
If you don’t want to increase the GI quality with adding more subdivisions or using "detail enhancement ", you could try to add few low intensity light sources in order to bring more direct light in the area.
You can turn Off “GI” for a moment, adjust your lighting setup, then turn it On again. Hope this will help.
perhaps a couple of subtle plane lights facing upwards? don’t want to muck around with the GI too much..
Vray has 2 perfect solutions for this…& quick & easy I may add.
1. Use the GI subdivision multiplier in the Object properties dialog window. Set the multiplier to 2.0 or 3.0 so that it uses 2 or 3 times times the GI subdivision on that object making it nice & clean.
2. Use the detail enhancement option on the Irradiance Map setup [this uses BF in just the detailed areas to a radius you specify.
Hope this helps
Geometry like this can be quite tricky for an Irr. Map.
When you render with “incremental add” the Irradiance needs some frames to “get in groove” 
and will be much smoother
after like 10 frames. So you should anyway prerender only the irradiance map and use a stored map for the final rendering.
Check you secondary GI. Blotches like this can also come from the Lightcache (I guess you´re using LC as secondary ?)
To check your secondary use LC as primary and secondary to see if blotches occure allready at this stage. The secondary must
not be perfect but should be fairly smooth. Sometimes decreasing the LC sample size while increasing the Subdivs. can help.
Than check the sample distribution of your Irradiance Map. As a basic rule, you should have as many samples as possible in areas
where a lot of light changing is happening (corners, gaps and so on) and as few samples as possible in areas where not much is happening like
plain walls or ceilings. This can mean that you will end with settings like -8 -1 and your threshold are at their limits. But this is fine. Especially the
clr. threshold is very important here.
Bad sample distribution will do lots of blotches.
http://sorceress.netfrag.org/optix/bugs/s\_irmap\_problem\_01.jpg
Good sample distribution
http://sorceress.netfrag.org/optix/bugs/s\_irmap\_problem\_02.jpg
If anything fails give those ceiling objects their own Vray Material and turn of “use irradiance map”. Than only those objects will use a BF GI for rendering.
