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Help with lighting please.

Michael Emo

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Yes I have secondary bounces on. The value is set to .49. So perhaps I should bump the value up to a much higher value. I will try .75 and see how much that helps.


Using Quasi MC. There I have Subdivisions set to 16 and Secondary bounces set to 3. Should I up this value at the risk of increasing my rendering time by a lot or does it not affect it that much?


Thanks :)

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To be physically real, you don't need to change the multipliers. 1.0 and 1.0 are just fine. Setting your second. bounces multiplier to a value lower than 1 is like saying "look, I know there will be a lot o light bouncing there, but I just want half of it". Also, try using Light Cache instead of QMC this time. You'll get faster results.

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Here is the 2nd test.


For Qmc, I had secondary bounces set to 3 and subdivisions set to 16


For LightCache, I had subdivisions set to 1000, sample size 0.02 and 'store direct light' checked. Number of passes = 4. Filter = Nearest.


Seems to have lightened it up a little bit, but not much. Anything I could try perhaps? I really hope I don't have to start throwing individual lights in all those areas because there are a ton of them on this building.

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Do you have any internals modelled? Id put some quick floors and walls in the model with a white material and see if that helps.


Do you have glass as well? Its hard to tell, maybe bump up the reflection value.


Put in a direct light as well that will really improve it.

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It looks like the issue has to do with a couple of things. The material at the base of the model is very dark - that's going to vastly reduce the amount of light being bounced back up to the building. You could lighten this material, or you could increase the amount of GI it generates.


The material inside the building also looks very dark, particularly inside those balcony areas and at the underside of the roof, so what little light is being bounced back up at the building is being mostly absorbed by these materials.


If I were you I would try adjusting these values and see what happens.

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no internals are models. I could throw in some floors real quick. I couldn't figure out the windows thing and after tweaking and tweaking with it I decided to fake it in PSD until I can figure it out.


The windows...what would they reflect since I don't have HDR applied? I tried applying HDR but couldn't get it to work right and not enough time to mess around with it before I need to have it done. So I changed the windows to not be see through but did a poor job because i don't yet understand how to properly adjust all the values. The windows are just a single mesh plan (no thickness).


I have a direct target light on the side of the building. I used VRay shadows as attribute for that light. Do I need another one inside the building? I will add some floors really quick and then change value of windows to go back to 'see-through'.


The materials are dark, that is true. So I should have a light inside the building?


I will try increasing the GI of the material at the bottom. This project has been challenging on a number of fronts but I like the challenge. Just wish it wasn't such a hectic deadline.


Thanks for your help and suggestions. I appreciate it!


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Id definately put in some floors quickly, just boxes will do, also a wall a few meters back from the windows so it doesnt look endlessly black!


Put a shell modifier on the windows and give them some thickness so they act properly within vray.


Use a transperant material, and a falloff map in the reflect slot, set it to fresnel with a ior of 1.7 ish and maybe bring the black slot to a grey if you want to exaggerate the reflections, or even use a perpendicular/parralell map, i know its not 'physically correct' but its my quick fix when clients tell em the windows are not reflective enough.


For a reflection map, try downloading teh 'free background rig' posted here a while back (apologies I cant remember who posted it?). Or bump the vray environment overide up to 2 or so, with a light blue colour.


I think if you bring the direct light around and put it so half teh building is in light and hlaf shadow it will improve alot.


Hop my rambling helps some!

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Hum... I just figured there's no direct light there. Even though you have a direct light on the other side, it doesn't seem to be enough light to get inside the balcony. And, to be really honest, it doesn't seem you have a direct light in the scene at all. How strong is it? Try using a VRaySun (multiplier = 0.01 for starts) and a VRaySky in the GI Environment (make sure it's attached to the sun node and has the same attributes). Let's see how this turns out.

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Thanks! I am in the process of doing all that right now. Shouldn't take me long. Let's see how things go. I'll post soon as I get it rendered.


I need to figure out the Direct light thing and Vray sun. Again, I totally appreciate your advice and opinions.

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I added a VraySun. Set intensity multiplier to 0.01.

Do I position VraySun directly overhead, or off to the side where it hits the front (camera side) of the building (is that dumb question)?


Set GI (overide) Environment Map to VraySky.

Multiplier to 2.0 per nicnic comments and added slightly blue tint.

Added SHELL modifier to glass so they react properly in Vray conditions.


Rick, how do I attach VraySky to sunnode? Tried right-clicking to look for settings but couldn't find anything.


Changed glass values per nicnic comments.


Didn't add internal floor yet. Wanted to post this to get more opinion.


The sky looks cool and evening-like. And it definitely added some light to those balconies. Should I take down the GI Overide intensifier from 2.0?

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woah! overbright.


Id get used to using direct and environment before jumping into sun sky unless you are fairly confident using and tweaking a normal setup!


What colour mapping are you using?


I generally use Reinhard, which can be adjusted to be a mix of linear and exponential. 1 being linear, 0 being exponential. I use between 0.6 and 0.7 on externals to acheive good light distribution whilst maintaining strong contrast.


Unless you are using LWF?

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Haha Nicnic :)


Yes it got crazy bright. Trying all kinds of setting variances with VraySun but can't seem to dial it in. Found this helpful page: http://www.spot3d.com/vray/help/150R1/vraysun_sky_param.htm


But yeah it's difficult. I can't figure out how the heck to get to that VraySKY parameters dialog shown here: http://www.spot3d.com/vray/help/150R1/vraysun_sky_param.htm


Color mapping I'm using is Linear Multiply.


Trying Reinhard right now at .6 to see what that produces.

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A tip I picked up from Gnomon's Exterior Lighting:


Make a plane, make it 100% white, 100% reflective, and then select the plane, edit, object properties, and untick the VISIBLE TO CAMERA.


You now have a bounce reflector - just like photographers use.


Position it low near the building and angle it so it will reflect light up into the dark areas.


It's a good trick and is useful for using global illumination to light up dark areas.


Obviously, you need to use secondary bounces.


Hope that helps.

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Hi, try this with vray:

1-place a vray light, convert it to dome, you will use this as ambient light.

2-Place also a direct light, vray shadows on.

3-GI on.

4-Place a HDRI as environment ,

5-overwrite max´s environment, in vray

That should give you a nice and smooth lighting for the balconies.

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Ok, I downloaded your file and found a few things:


- the VRaySky didn't have a sun node assigned to it

- there was a direct light there, which was causing the burned areas

- QMC+Lightcache? I don't think so. Keep it simple and use IrrMap for primary bounces.

- your rQMC Noise Threshold was too low for this version of VRay. You don't need (here) to use 0.005... use 0.01 instead.

- everything there has glossiness. Your glass has 0.95, which is nice if you want to see light on it, but not so good for rendertimes. Leave the reflection glossiness as 1 and lower the highlight instead.

- it's been a while since I worked in the US, but your units seem wrong to me. You set 1 unit = 1 foot. The correct (if I recall) is leaving it the way it is (1 unit = 1 inch). It doesn't sound like a big deal, but it makes a huge difference.

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Alriiht. Here is it guys. This is the *ahem* finished product. Thanks for all your effort to help me out on this beast of a project. Rick, nicnic and all the rest of you who put forward some saavy techniques and information, I totally appreciate that!


Unfortunately/Fortunately, the clients wants to make changes now to the structure. It's not the arch, it's the developer driving me insane with these changes!


And before you rip into my rendering...just know that 'he' wanted to see mega amounts of flowers on there and a certain tree at a certain height, trimmed just a certain way...you get my drift.


Let me know what you think though! Oh and I didn't get to pick the exact camera angle either. I would have gone for something a bit different.


Oh yah, and it's so open in front becaue I knew I would have to add an ugly dark colored wrougt-iron fence because....yep, the owner wants to see it. It's 6' tall and runs in between the two sidewalks! How ugly is that going to be!


Thanks again for your help/encouragement. You guys helped me figure out a lot of things.



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