Hi,
Finally had time to get back at this scene. It simply is taking much to long to render in my option and even then the results is not looking that clean. For this test I have over ride most of the textures with just a simple grey VRay texture and still it took over 18h and 38min to complete. (having all the texture set it takes much longer)
I have attached screen grabs of my settings, if anything more is needed please let me know.
Looking forward to getting back on track.
Thanks
Geo
Are they all vray materials? What do you have in the ‘glossy override’?
Theres no big issue with your settings - they could be optimised, but youve not clicked on a ‘take ages and look awful’ button anywhere. Its something object/material/light based.
Hi Geo,
The sample size on your lightcache looks small to me. The default is 0.02 and I sometimes use 0.01 but never as low as 0.001.
Your settings will use a lot of memory and be quite noisy as there won’t be many paths traced per sample.
Dan
I would try merging it into a brand new model and see if that helps.
Spots might be reflected/refracted GI caustics too. If you’ve got actually visible light sources, try to lover their intensity towards gi calculation. (either with a wrapper, or override shader, I prefer the override, or simply just turn off gi generation for those) A visible Sun disc can also cause some splotches. And as Daniel said, your lightcace sample size is too small, so, it’s might be just that.
Oh, and you could increase the hsphere subdivs for the irradiance map, 50 might be a bit low for those corners.
And if this is an old scene, make sure to reset the Vray settings, and set it up from scratch (merging might help also, does the same). I know it’s not too technical, not exact, and just sound like voodoo, but we had many scenes where this was the solutin regardless of what the old and new parameters were…
Best regards,
A.
Thanks for the feedback thus far.
They are all Vray mats. Are you refering to the glossy setting of each material CG or which?
I had such a small setting for LC to try and get rid of noise, but it seems I was trying at the wrong location. Will set it back to 0.02
Aldaryn - the most questions for you:)
Should I followyou advice in changing the lights to not contribute to gi, how will this impact on the illumination of the space - will it be darker?
Also can you explain in more detail the steps for an overide shader?
The sun is visible and I will test the alternative.
What sort of setting would be better for hsphere in this scene?
Little bit more info on the scene - The lights are ies lights - I know they are slower that VRay lights, but I didn’t expect such an penalty.
Most of the furniture and other eyecandy is Xref files…I recall reading somewhere on this forum recently that it might not be a good option to have Xref files - is this so?
Thanks
Vray Physical Camera might be adding to the time… try a standard camera and see if it helps at all. And maybe switch the AA to Adaptive to see if it speeds up your materials.
Xrefs should not have any impact (maybe a little, the xref update time if you render in DR or remotely) on rendertime, since they’re “merged” into the scene before render. Xref related bugs are different, but annoying nevertheless. 
Having very bright and small geometry, such as lightbulbs in the scene can cause splotches. The GI engine will find these hotspots, and try to take their intensity into account when calculating the solution, but thanks to how gi in VRay currently works “object” lights like these tend to need very, very large amount of samples to render smooth. This is a reason why you use direct lights for point like lightsources. However, an ies light has no physical volume, it’s not present in the scene in that way, so people tend to put light emitting geometry where the light bulb should be to have convincing reflections, or to see the actual light source itself. But since you don’t need these lights to actually illuminate the scene, it’s best to keep them out of the GI solution.
Splotches go wild when “GI caustics” somes into the picture, so if you’ve got refractive shaders in there, and a small geometric lightsource contributing energy to the gi solution, splotches will start to appear. Just think of an average light fixture, chromes and glasses all over, multiple specular transmittance, put in a small high energy object, turn on gi caustics, and voila, you’ve got yourself a disco ball.
Hope it makes any sense, had to type, again, fast, hell just broke loose here in our office.
And yes, it’s such a pity that the max implementation of ies lights is such a bloody bruteforce approach. Quite far from “fast” I must say. Let’s hope Vlado adds ies support into the MAX build of Vray too.
Oh, and don’t worry about the Physical cam, has very little to do with your rendertime if you set the exposure correctly. Just don’t under or overexpose it. Under will bring undersampled areas, so splotches, noise, etc, and overexposed will mean longer rendertimes (oversampled areas).
Best regards,
A.
Why would vray cam be adding to the time ?
Oops, didnt see the post above..sorry
i’ve had similar issues with regards to the long timeframes in the past in scenes similar to this.
I think it a combination of modelling and the IES lights or the number of lights in your scene. I use a lot of models from other software and import them but i generally have to set the images up as separate scenes with a limited number of lights and delete parts of the model not visible.
IES lights are a bit weird for me. Sometimes scenes render resonably quickly but sometimes they can take 24+ hours for a decent resolution. what bothers me is that your rendering take 18+ hours at 800x600…thats pretty terrible!
I think you could do a few tests…
render the scene with default vray settings
render the scene without ies lights
render the scene as you have it set up with everything out of the line of sight deleted (even hidden things)
render the scene with no displacement if you have any
When it is rendering, look for errors…
I’ve had problems with geometry in the past where i’ve tried to bevel edges from an imported model that can cause very bad blotching or the entire scene to render out black/purple/splotchy (almost anything is possible!). The problem is that all it takes is one peice of invalid geometry and your scene goes nuts.
whenever I use IES lights i know the scene will render more slowly so i generally am more careful about things that will effect render times further. I almost always reduce the default light level of the IES light especially if it is close to other geometry…because i remember from the past that lights intersecting geometry can be very bad. I noticed in your dining room on the curtains that there is a very bright spot which could be the initial source of the blotching. I would probably start with these lights and do a test with them deleted from the scene.
anyway good luck…trouble shooting this kind of problem can be very frustrating and time consuming but on a positive note, you are forced to learn how things work a bit better!
Thanks again to all contributed thus far.
I am working through these options.
Paulison, do you ever work with files coming from MicroStation? (thats the program I use for all my arch design/modelling) I am sure that some of my issues are related to this workflow, but also feel that with the right steps they can me brought down to the bear mim.
Yes the speed of ies lights almost seem to be determined by each individual ies data file…as if some as setup in away which makes them more efficient.
I keep missing it, where do I find the reset button for the VRay settings.
Thanks
O yes, something I have noticed with this image, is a “funny” linear pattern being displayed while the LC is calculated. I will post a sample later today.
- verify the subdivisions of your glossies reflection and refractions in materials scenes not over 20 would be better and faster never over 50 as the older 1.09.xx versions;
-seems from the images watching the nois effects on the wall and ceiling that u have some double geometries at the same coordinates (same position) generally this produces that noise artifact and makes longer the rendertimes;
- verify and reduce to 8 or 16 the subdivisions of the vraylights or vrayshadows subdivisions if u are using other light sources than vraylights;
- verify irrad map subdivisions or if u using general multiplier in rqmc sections reduce the irrad map subds until u get a value that produce a total amount of 50_60 subds;
- verify intensity of lights too strong light that produces burned areas request more time to be calculated;
- verify adaptive subdivision value in rqmc section if is not too low like 0.5 or lower
-verify u have not more than one sun sources outside the room
-verify your reflections/refractions depth values for glasses and so on
-use lc for glossies material calculation option u’ll cut a lot the times without loosing quality
- it is important to know even on wich pc u calculate his image (hardware it has)
- I’d use the cutoff option in vraylights options is created when are present a lot of lights
- I’d fake where possible the group of lights with one light helps rendertimes and avoid the high intensity values for lights and avoid to put lights too close to geometries ray hates it and generate with splotches as the right bottomside of the image show
Hope it helps some of them if i didn’t read something before wrote by other users I do my apologize i read and wrote this message hoping it helps
there are some other things to control but those came into my mind for first
bye
i find interiors take forever to render too especially if you want to light them realistically.
18 hrs for that does sound like a lot but i have no idea what computer(s) you have
The settings look low to me.
I think at least one of your problems is the “medium” Irradiance Settings. I ran into similar problems, too.
It produces way to much samples where you don´t need them. Try the following settings.
min rate -5
max rate -1
dist. treshold. 0,3
This should make lower render times but much smoother result.
If you loose detail, tweak the tresholds.
also render the scene with “show samples” on. and play with the different tresholds.
Adjust the treshold so you don´t have unnecessary samples in areas where not much is happening (plain wall for example).
As more samples you have, as more subdiv´s you´ll need to make them clean.
also play with the min rate. don´t fear to set them even lower.. to -6 or even more.
Now this is just for the GI part. Other factors like glossines of course can have a major impact on rendertimes, too.
Hey WWX i import a lot from archicad and i’m not having so many geometry errors now from archicad 10, but previously i occasionally had some issues. Sometimes converting all geometry to poly would help me by welding some points and cleaning things up a bit.
I think that as someone else pointed out, it could be the light sources. They may be too bright which slows the rendering down a lot but also if they are bright and close to or intersecting geometry i think (could be wrong) that you may get strange things happening. So i think you could start by setting up a white scene just with a couple of lights and see if you get the weird blotching. I dont think that i’ve seen a lightcache look like your screenshot before but obviously something is off. as someone else said, its more likely to be lights or geometry than general settings but if you want to reset to default vray settings there are a couple of ways (or more):
copy and paste everything into a new scene - this may be worth trying either way. Or, load a preset… go to render and down the bottom to the left of render is a list of presets - there should be a default one in there. If there isnt a default one, start a new scene and save a preset using the vray defaults. its pretty handy as a staring point for new jobs to set up your own list of presets.