[lsega77]

So I've been showing this to a few people and I keep getting the comment that you can't tell this render from a Vray. Which is absolutely frustrating because I'm obviously not looking for a vray look with this (if all I'm achieving with m~r is vray 'like' images I might as well use vray).

so where am i going wrong here?



look for honest critique and direction. The subject matter is boring I know but I'm using this as a case study in achieving realism and don't want to be fixated on the 'design' of the building itself (it from an old project of an existing school building).

Settings:

Phys. sky - sun (madrid) gmt 5 - hour 13 min 30

all mats are two bsdf simple blends (90-10 or 85-15 mixes except for the glass).

Luis

PS - need to add a fence around perimeter and move phone stands.

____________________________________________________________

So I've spent some time studying brick (it's funny being out in public and staring at a brick wall people think you're freakin nuts).

Here's my first attempt at dirty-ing up the brick facades. I did the two major facade and but haven't done the front bay yet Just looking for some feedback that I'm on the right track.

I'd like to focus on the asphalt next as I agree with Mihai's statement of how boring it is.

Luis

PS- Oh I obviously changed the lighting to focus on the front of the building. I had to reduce the intensity of my hdri illumination.

[mverta]

Luis -

Assuming you're not going to alter the geometry in any way (I would; things like pulling the window panes all slightly out of perfect) then it's Materials, materials, materials, materials.

Here, the texture maps especially are very "generated" looking, but let's start at the very basics. The first question I'm going to ask is: how many Lamberts are you using?

Now, a lot of people get great results (me, too on rare occaision) from lamberts. In fact, the old "beta" plastic was a lambert with a glossy coat! But the problem with Lamberts is they're 100% diffuse - this doesn't exist in nature, and the result is overly flat lighting in a lot of cases. Now, I'm not saying that Lambertian won't work for this, but I'd say the first place to start debugging an image is by asking the question: How many times have I violated real-world values on my way to photorealism? If you find you're using 100% solid colors which don't exist in nature, or generated texture maps, which also don't exist in nature, plus Lambertian mode all over the place, you've already severly handicapped yourself, and will have almost no chance of getting photoreal.

But perhaps your goal isn't truly photoreal... just something better than this "VRay" look. Well in either case, I'd take the exact render you have right now, and change all your Lamberts to 99, then change them all to 90. Place the 3 renders side-by-side and see if any of them feel better. If it looks like none of that is making a difference with the lighting, then we know that the place to work on is likely your maps.

The maps need work, anyway, yes. But I'm a big supporter of getting the light properties together first. The way your surface is returning light actually plays a big role in HOW you do your maps, imo.

_Mike

[Mihai]

Well start by asking yourself what you don't like with this image - do it piece by piece...

It seems you're going to fast with the materials. First the asphalt texture, it's too repetitive and bland looking.

The sidewalk, looks perfectly uniform, not a hint of small variations at least in the texture and reflection, if you don't want to dirty it up.

Too many materials look too matt, like they're missing some reflection. The stop lights for example, the garbage bin, and the building itself.

Start with each area and improve it.

One last thing, you need to start modeling a lot of the elements with a slight bevel. It catches the light and brings out the form. It adds a hundred small "details" to your image, so it makes appear more interesting. The building entrance for example, the ledges...everything that has a perfectly sharp angle should be beveled a bit.

[lsega77]

thanks guys.

@Mverta: I'm definitely shooting for photo-realism here. it's the primary reason I bouth M~R to begin with.

My mats are usually 2 bsdf layers 1 diffuse (lambert with texture) 1 with variable roughness for reflection layer. so you're saying no matter how many layers none should truly be lambert?

@Mihai: Some elements don't have textures on them. What I'm really concerned with is the lighting at this point but I see where you're saying the textures are failing me.

I'll tweak the model to bevel all the edges a bit (funny thing is I actually know that but for whatever reason didn't do it to this model - thought exteriors didn't really need it).

Luis

[mverta]

Yes, absolutely use bevels when you can. Maxwell especially takes advantage of them.

And there's NO rule that is absolute, 100%, Luis. I'm just saying that in my experience, the non-physical "bullshit" of Lambertian mode actually shows up as bullshit in a render sometimes; no surprise. But it's also true that sometimes it works better than any other solution for a material. Cloth comes to mind. But in this case, I would definitely recommend a quick pass turning them all to 99 and then to 90, even 85 just to see the lighting effect on the scale and surfaces.

_Mike

[mverta]

Another thing, about texture maps for this kind of thing...

The human brain is amazing at recognizing patterns. Tiling is patterns. If this is the distance for your render, what I'd do is start with as high-res a photo of the largest section of bricks you can find. Then I'd take a UV snapshot of each face of the building and build 8k maps or bigger in Photoshop. You can always reduce them later.

I start by scaling my brick photo properly against the UV set, and seeing how much area it covers. Then I'd go ahead an tile it to fill the rest of the map. But then I'd begin painting on the huge map with other layers of photo-sourced stuff, like dirt, color variations, etc. I NEVER use colors, ALWAYS photos as my sources for all painting. So for example, I might take a few photos of the floor of my garage, which are beautiful dirty concrete with oil stains on them, and steal pieces of it, or use it in Multiply, Overlay or Screen mode to alter the bricks across the entire map, hiding the seams. I'd also make irregularities along all the grout grooves as well. To do this, I'd probably bake out an ambient occlusion pass so I had a matte source/selection source for just the grooves, and then replace those grooves with dirt, etc. You can even distort the grooves with a high-frequency displace pattern and use it as a bump later, eroding the edges of the bricks.

There are limitless things you can do in the painting, but it's the best way to stop the tiling nightmare.

_Mike

[michaelplogue]

I wouldn't necessarily say it looks V-rayish. More that it looks CG-ish.

Well, Here's my very first impressions (remember, you asked for it! ):

1. Repeating tiles

The very first thing I look for (because it's always a dead giveaway) is repeating textures. This is usually the number one killer of renderings, simply because it is so noticeable. Although you might take a hit in rendering time, it's well worth the while to make large versions of your brick textures that does not have any visible repeating patterns. For this building, you wouldn't need to make it overly huge, since your walls are broken up by a lot of windows. Looking at the nearest section (two floors, three windows) behind the light pole: I'd try to make the brick texture approximately 2/3rd's of this space (width & height). That should be large enough to prevent any visible tiling on the rest of the building.

2. Too Clean

Even if this was a brand new building, I'd add a stain/dirt layer to break things up. Number two killer of renderings: Too clean. Creating a stain layer, having different UV tiling than your bricks, will also help hide any repeating patterns. In some of my really "dirty" renderings, I have used as many as five different 'dirt/stain' layers, each with a different UV tiling amounts so there was very little chance of seeing any repeating pattern.

3. Basic materials (no maps)

Killer #3. I'm of the opinion that nearly every material should have some sort of map applied to it. Even if it's only a bump map. Rarely will you ever encounter perfection in the real world. There's no such thing as a perfect paint job, concrete pour, brick laying, chunk of metal, etc. Our mind knows this, so whenever it sees something that's 'perfect,' it automatically classifies it as 'unnatural.' This goes back to things being too clean. So - for example - I'd put a very subtle noise map on your brown trim material. If you can find a photographic image that you can use or modify, even better.

4. Photographic maps, versus CG maps.

Whenever possible, always try to use photograph-based maps instead of those nice and clean, 'tileable' maps you can find everywhere on the internet. This again goes back to things being too clean. This also applies to things being to 'regular.' Bricks are never perfectly square, boards are never perfectly straight or lie perfectly flat. I don't care how good anyone is in creating CG textures in photoshop. Nothing can beat using a photograph of the real thing.

So, those are my four basic rules that - in my mind - makes the difference between having a photorealistic rendering, versus a CG-ish rendering.

1: Repeating Tiles (Very Bad)
2. Clean (Bad)
3. No Mapping (Bad)
4. Photograph based maps (Very Good)

I think the lighting is probably OK, though I would probably use a combination HDRI and physical sun to achieve a more realistic look. After seeing a gazillion renderings with the same physical sky - as realistic as it may be - they start to look CG-ish after a while.

If this is the actual orientation of the building (I'm assuming it faces almost directly south) then there's not a lot you can do to give it a more dramatic look. You could try putting the sun in a position later in the evening. This would put the near side (behind the tree) in shadow, and give you some more contrast and some darker mid-tones to play with. If you can reconstruct the buildings around it (just the basic shapes), their shadows on the building will add to it's realism.

There's my two cents worth. Hope this helps!

Cheers!

[lsega77]

@Mverta: great tip! will definitely start painting with photos!

@MichaelPLogue: Thanks for the thorough analysis my friend! Definitely going to take all into consideration!

[Peder]

I would try changing the angle of the lighting. Assuming it is around noon in your image I would try having the light from later in the afternoon. Photographers often try to catch the lighting in the morning or evening. Also your eyes are led across the front of the building in your image. I think the lighting would appear less dull if the main lightsource came from "within" the image.

Peder

[Peder]

Also in keeping with my previous argument. The eye is drawn to warmer colours so there is a mismatch of fore vs background in the image. Look at paintings, often you will have the warmer center of focus toward the middle and cooler colours in the periphery/background beeing read as less important.

[lsega77]

Thanks Peder. Very good stuff!

Luis

[w i l l]

Wow. The thread of help.

[acquiesse]

can we put these hints into a sticky/tutorial?

[KurtS]

Many very good tips and hints in this topic!

I also think you can learn a lot by studying some great examples, as these two fantastic renderings by Marek Denko:

http://marekdenko.net/3dgallery/039_001.jpg
http://marekdenko.net/3dgallery/041_001sml.jpg

[lebbeus]

can we put these hints into a sticky/tutorial?

I agree