Rectangular lights create noisy reflections??

[thomthom]

Re: Rectangular lights create noisy reflections??

He could be a student with a deadline.

Jackson's tip are very good ones. It'd fit well into the Tips and Tricks section.

Only thing I don't agree on is the claim that wood textures don't need reflective layers. Having a nice glossy fresnel reflection often makes that material come to live instead of looking dead. But that depends on the finish of the wood.

Sorry to be an @sshole about it- I was going to post the model back with my changes, but I'm not in the business of giving away vismats, visopts and SU modelling which have taken me years to learn and develop just so someone else can be paid for it. The tips above and in many of the VfSU General Forum threads plus the freely downloadable visopts and vismats on this site should be more than sufficient to get your renders up to scratch so you can start hitting deadlines.

You shouldn't worry. Your post was nothing but very informative and helpful.

[stevebo]

Re: Rectangular lights create noisy reflections??

Actually no Thomthom... it was a project for work that I'm paid for. I'm extremely sorry for any insinuations that made it seem like you had to help me! I most certainly did not want you to do the work for me, and I could not feel worse about it. The whole thing about perfecting was more for myself rather than the client. For the client, it's only indicative. Again... I'm really sorry for any trouble I caused!

But I am most certainly VERY thankful for all the helps and tips that you have given me Jackson! I'm very glad that you did not post me the model because this way, I can truly learn the techniques via actually using them.

1) What does keeping the faces with normals facing outwards actually achieve?

2) I will keep that in mind most definitely!

3) I actually read about that after I had posted this model, so I have started to change my other models

4) I don't actually recall changing the Vray settings to be honest, but I will keep that in mind!

5) How would I polycrunch the meshes in SU?

6) I suppose not for the wood on the wardrobe and such, but I actually wanted the reflectiveness on the floor. As Damien said earlier, it must have been the subdivisions of the reflection layer that caused the graininess, correct?

7)

I will do so

9)I will definitely try that!

You weren't an @sshole about the situation at all! I'm the one who troubled you, so my deepest apologies to you Jackson. And I hope you know that you have truly helped me! Like Thomthom said, I think these would go well into the tips and tricks section!

[thomthom]

Re: Rectangular lights create noisy reflections??

1) What does keeping the faces with normals facing outwards actually achieve?

Makes your model clean.

SU is rather forgiving with front side and back side. Doesn't really matter for SU.
But often other 3D application will only display front side of a face - if you look from behind you see through it. You have to manually say that you want the backside to show.
And also, this goes for Sketchup as well, tools that process the geometry will some times need the faces to be faced in the proper direction in order to perform the task correctly.

The bottom line is that 3d software usually works better when you have your normals sorted correctly. SU might be forgiving, but when you start sharing the model data between other software, modellers or renderers alike, keeping your normals under control will save you lots of frustration. It certainly help with a bit of OCD tendencies to get the discipline to always ensure the normals in you SU model is organised properly.

[Jackson_cg]

Re: Rectangular lights create noisy reflections??

No problem Steve,

I was pretty sure you are a good guy, that's why I was up for looking at your model for you, but I've seen posts on forums in the past where contributers were offering advice, fixing and reposting models or textures and then suddenly the guy posts something along the lines of:

"Can't you get that back to me? Hand-in is tomorrow and I really need this done!".

Where is a "Get-off-your-lazy-@ss-and-do-it-yourself-instead-of-expecting-your-professors/clients-to-reward-you-for-someone-else's-skills-and-hard-work" smiley when you need one?!

Or the guy who posted a question here and when he didn't get a reply within 2 hours posted "What a terrible website". Idiot!

You're obviously not one of "them", so no hard feelings!

Before I go on to answer your questions I forgot to mention another tip, probably the most fundamental- some of your geometry (the ceiling and a couple of other faces) didn't actually have a material applied- it was just the SU default colour (horrible magnolia, though it looks almost white in SU's viewport). As the reflected light from a ceiling will contribute more to the scene than almost any other surface it is imperative that you have control over it's material and by using the SU default colour you immediately lose that control. So if there's one SU top tip for ALL render plug-ins I could offer it would be:

Set up a custom SU "style"which has two very distinct colours for front and back faces- I use extremely bright yellow and blue as I am very unlikely to ever use those colours as an actual material in an architectural model, but any contrasting colours would work in the same way. This way, at any stage I can easily see which faces have had materials applied and which just have the default material. I also usually work in monochrome mode when doing actual modelling as it allows me to easily ensure that front faces (normals) are facing outwards as I go along and I use hotkeys to switch between textured and monochrome render modes in SU. Note the blue "back faces" of the single faced glass- it's usually fine for non-refractive transparent faces to have the normal facing away from the camera. I can't speak for all render progs, but I've never had a problem with single-faced glass in VRay (as long as it has NO refraction).




1 ) Re: normal orientation, Thom explained it perfectly above. When using renderers which support normal mapping, normal orientation diligence is even more important.


5) Unless someone's written a ruby script I don't know about, polycrunching in SU is just manually editing a mesh to make it look similar, but with less polys- very tedious work. A much better option is "Meshlab" http://meshlab.sourceforge.net/; a fantastic open-source free program which import and exports most of the common 3d modelling formats and has an excellent poly-reducing function. It does a thousand other things too (900 of which I don't understand ), but the one I use 95% of the time is:

Filters>Remeshing, Reconstruction and Simplification>Quadric Edge Collapse Decimation

... in other words: "Polycrunch"

Just set the target number of polys (usually takes a few trials before you'll be happy) and if it's important that the edges of the mesh remain exactly as they were before polycrunching (e.g. if they have to "fit" to some other geometry in your SU model) tick "Preserve Boundary of the mesh". It's perfect for sorting out unneccessarily high-poly imported 3ds meshes, but I've found it's also very useful for cleaning up mega-poly-meshes created in SU when doing lots of editing with Fredo's brilliant bending/rotating/scaling "Fredoscale" ruby. I did a lot of editing of some already-high-poly curtains in SU recently to make them appear like they were blowing open and the model became very slow. On switching "Hidden Geometry" on I saw that Fredo's ruby had created masses of extra faces, probably 3 or 4 times as many as before, so I exported the curtain as obj, crunched them in Meshlab (preserved boundary), imported them back into SU as 3ds and they looked more or less exactly the same, but with a fraction of the polys and the model was easily workable again (and parsed and rendered faster!).



6) My point exactly: in an ideal rendering world our CPUs would be measured in Yottahertz, all materials would have reflection (500 subdivs) and it would render in real time, but back in 2009 I am always looking for ways to cut my render times. Sometimes the final image demands 100% realistic reflective materials, sometimes it doesn't. In my Barcelona Pavilion model the green marble walls should actually have fresnel reflection mapping, but as they fill a very large portion of most of the rendered viewports and there are already a lot of non-glossy reflective materials in the scene the render times would be approaching Maxwell proportions!

I compared 2 small test renders and decided that it didn't contribute enough to the final image to justify rendering for days so I just disabled reflection for that material. Just think how long the VRay "Region Division" square gets "stuck" on a surface with 64 subdiv reflection compared to a plain matt white plaster wall. Then put a 64 subdiv stainless-steel window frame next to it and they are now reflecting each other... then surround them with 64 subdivs walls and so on and so on- the more chance that one non-glossy reflective face will be reflecting another non-glossy reflective face will increase your render times enormously. One trick if you really need large areas of non-glossy reflective materials, but can't afford the render times is to do 2 or 3 separate renders, but disable different materials' reflectivity in each, then Photoshop them together and erase the relevant parts. This way VRay is only having to calculate a non-glossy reflective material reflecting non-reflective materials so it's a much simpler and therefore faster calculation. It can be many times faster to render 3 or 4 times this way and PS them together than to tie up your computer for 24 hours or more.

In your image I'm not sure all the wood absolutely needs reflection, especially the wall behind the bed and the coving. The floor definitely needs reflection (and a much better diffuse map and texture scaling IMO), probably the doors too and, as the wardrobe is fairly dominant I'd probably keep reflection on it too. You should consider whether an object is actually reflecting anything important or not. Polished floors more or less always need reflection as they tend to reflect light from windows and luminaires which contribute a lot to the feel of a room. A wooden panelled wall with no obvious light sources opposite it and facing straight towards the camera would probably reflect very little (due to the fresnel effect), but VRay would still have to calculate it so if you can get away with disabling reflection on it, why not?


Wow, this post is so long I probably should add all this to Tip & Tricks.

[thomthom]

Re: Rectangular lights create noisy reflections??

Dale got a Poly Reducer plugin: http://forums.sketchucation.com/view...p?f=180&t=9789

But I'm not sure how well it works. I'm not sure if a Su Ruby based poly reducer will ever be effective.

I some times have to make terrains out of 3D situation plans. Often the polylines are very detailed which leas to a very dense mesh. On my last project I got a very large plan what created a 1.000.000 polygon mesh. But using 3D studio max's modifiers I got it down to 25.000.

[Jackson_cg]

Re: Rectangular lights create noisy reflections??

1,000,000 polys down to 25,000? Now that's a saving!

[stevebo]

Re: Rectangular lights create noisy reflections??

That is indeed a very long post Jackson!

Thanks for all the tips. I'll need to give it another read later and digest it properly.

I've actually started changing the style of the default colours lately. Again, after this model. I didn't know how to do it before, but yes, it really does help and it really is a very good tip! I'll spend some time today trying to refine the model! Thanks! Once I get some results, I'll repost it

[thomthom]

Re: Rectangular lights create noisy reflections??

That is indeed a very long post Jackson!

Thanks for all the tips. I'll need to give it another read later and digest it properly.

I've actually started changing the style of the default colours lately. Again, after this model. I didn't know how to do it before, but yes, it really does help and it really is a very good tip! I'll spend some time today trying to refine the model! Thanks! Once I get some results, I'll repost it

Note that V-Ray won't render the default material colour you define. It will always render front side as creamy white and backside as blue.

[stevebo]

Re: Rectangular lights create noisy reflections??

Note that V-Ray won't render the default material colour you define. It will always render front side as creamy white and backside as blue.

Yup, I know that

[stevebo]

Re: Rectangular lights create noisy reflections??



Here's an update! Seems much better! The rectangular light in the middle really helped. However, the image still seems a bit flat. Would that be a gamma correction thing? This image is actually slightly post processed in PS. I've lowered subdivs of pretty much everything and generally, all the settings lowered a bit .

[Jackson_cg]

Re: Rectangular lights create noisy reflections??

Looking good Steve!

I would:

1 ) Raise the rectangular light up to the same height as the bed head luminaires and probably increase it's scale and/or rotate it so it fills more of the room (it's causing a very obvious shadow in the right corner of the room). If necessary use 2 or 3 smaller rectangular lights and adjust and move them around them so that you can't see any "where-the-hell-are-they-coming-from-shadows"! I would probably also dial down the multiplier of that rectangular light a lot- I think that's the main reason why everything looks flat- it's completely drowning the other lights' contribution to the scene.

2 ) Dial down the emissive uplighter material as it's burning the ceiling

3 ) Turn up the bed head rect lamps so they actually cast light onto the wooden paneling they're fixed to and contribute to the scene. Maybe the side ones should just be for show (i.e. multipliers just high enough to light the wall), but turn the front facing ones up high so they cast shadows into the scene- it'll add depth and realism

4 ) Turn down the rect light in the bathroom door- IMO it's better to have a slight warm glow emitting from the bathroom hinting at a space beyond the one we're looking at.... unless.... there's not a big pile of gold in there is there?

5 ) Decrease the scale of the floor texture and reduce the multiplier of the bump map- the boards look too big and the joints are too deep- they look like tiles.

6) Find or make a properly tiling high-res wood texture which doesn't repeat as obviously as that one. Even just Photoshopping that one to remove those two big vertical dark stripes would make a huge difference to this render.

7) I would possibly reduce the FoV/increase the focal length and maybe rotate the camera so there's more window and less tv (although decisions like "TV vs. Window" are really up to the client). You obviously already know this, but as a general rule, I try to get a window in the frame as it indicates that this is a wonderful, spacious airy room with spectacular ocean views (even if it isn't!) as opposed to a windowless basement.

8 ) I would also find a camera height (I usually use between 1100 to 1400mm (4 to 4½ feet) where you can rotate the camera so it is as close to horizontal as possible so that all verticals in the model become parallel (vertical in the viewport). The reason it's lower than most people's actual eye level is because we have much greater peripheral vision than a render can convincingly show and we tend to focus our vision slightly downwards when we view spaces, so if you set the camera height it at 1700mm (5½ feet) it'll cut off too much floor in the render which looks very odd. This is by no means a you-must-always-do-this rule, but it is the same principle that architectural photographers use for flattering interior shots. The verticals in your image are ok, but when verticals really start converging it creates a very claustraphobic feeling, like a fish-eye lens, so it's usually best to keep them as parallel as possible. This doesn't apply to close-ups of details, they can be as fish-eye as you want. By rotating the camera to horizontal you'll also hopefully take those armchairs out of the viewport foreground- at the moment they look messy and distracting and it makes you feel like the viewer is stuck behind the furniture. If they're still in view, don't be afraid to hide them in SU before rendering- the client is extremely unlikely to complain that the tiny edge or corner of a piece of furniture is missing from one image of a set; they'll be too busy appreciating a good render. I learned this from the "real world" too- observing a very good architectural photographer working on a house interior for a couple of glossy magazines- he did more moving of furniture between shots than he did actual photographing! LOL

Hope this helps,
Jackson

[remon_v]

Re: Rectangular lights create noisy reflections??

good pointers Jackson... I haven't done any interior scene's yet but I might have to do them once in a while so I'm def gonna use these pointers

[40th]

Re: Rectangular lights create noisy reflections??

Now that i call a comment.
Jackson, you should give lessons. (and get payed for it )

[stevebo]

Re: Rectangular lights create noisy reflections??

Jackson. You, sir, are a god! Thanks for everything and I will be improving on this tomorrow or something . I actually ticked the box for no decay because what the rectangular light was doing was casting shadows that I did not want. But the render did take like 2-3 hours (didn't actually check), so maybe I should turn off no decay?

[Jackson_cg]

Re: Rectangular lights create noisy reflections??

Thanks guys!

If you're using a "fill" light (a rectangular light behind the camera facing into the viewport) then it should usually have "no decay" ticked as you want it to completely fill the whole scene without decaying at the far end. A rectangular "fill" light is, by default larger than the camera's focal point so shadows will always be invisible to the camera, just like the umbrella reflectors a photographer uses, but for the big horizontal light in your model it's best to have decay on so it doesn't cast shadows on objects at the edges of the room. You could, by the way use that method for this render, but I thought it would be nice to use a horizontal one at the same height as the luminaires on the wall instead so it would appear as if it was mostly them which were lighting the room rather than our fake invisible light. It's also a fine line between making the rect light big enough to eliminate odd shadows, while being careful that the light doesn't start start showing on the walls. I forgot to say- make sure the "Ignore Light Normals" box is ticked so light radiates evenly in all directions from the horiz rect light.

What size is the original render? 2-3 hours sounds rather long- how many subdivs do you have on your reflective materials? Decay on or off shouldn't affect render time much.