wrote this for Vue, but much applies to Bryce or any app :)

THE DEVIL IS IN THE DETAIL OF ART

I often see a simple, but huge flaw in a lot of 3D rendered art, a flaw which is so easy to miss, and so rarely explained in tutorials, etc that you may not notice it!

The wall of a real life building does not have perfecttly hard, straight edge. No, it is always chamfered off, by the plasterwork covering it, by damage, or simple fact ceramic bricks don't have razor sharp edges ;)

Because models in a 3D app are non-real geometry in 3D space, they can have PERFECT edges which are impossible in real life, just like a square drawn on a text book is "perfect" if drawn well, but in real life, even sharpened steel edges have some amount of thickness that light brilliantly sparkles off, and materials like wood and brick have far more rounded edges that scatter light in softer broader ways.
Your brain KNOWS this, instinctively, and if it doesn't see this kind of thing, if it doesn't see grime and wear and sun bleaching etc, it knows it sees something fake.
So, you have to provide the details the mind expects to see.
CGI is about ILLUSION!

The edges of items tend to get worn and scractched by passing things, faded by sun and wind damage, or have mud, snow and other material stuck to them in passing.

For example, say you make a Poser figure of a heroic warrior, the hems of his worn trousers should be ripped perhaps from the hard violent life you expect him to have, and be faded by wear, for he hasn't just bought them from a Gucci store! :P
Your mind knows this, and looks for it, when it does't see it, when it sees a fresh clean 3D model...it says "Uh uh! Fake!"

Another part of this is there should be dirt and grime and wear on nearly ALL textures in a scene. I absolutely cannot state how important plain old dirt and random difference in textures make to the reality of renders!
Doesn't take a lot to alter an object's materials to be more realistic, either.

I saw a gorgeous render, which for me, was weakened by simple fact several prominent foreground plants had all the exact same shade of colour and no "bump" on any leaf...which looked incredibly jarring, "fake", compared to the rest of the great pic.

The fault isn't often with the original model/item maker. Dirt and grime etc are very subjective to the scene, the artist's tastesetc. Plus they are a LOT of more work for the original creator to make, and it's hard enough making any 3D object in the first place.
For example, a building in the desert, you'd expect to be sun-bleached, have the lower couple of feet of walls to be sand blasted by wind and grit, etc.
But, same building in a medieval city in northern Europe you'd expect lot of moss on the walls, soot near the chimney, damp stains dripping down the walls etc.

Now, not every render requires such attention to detail, as everyone has their own "style" of what they like in work and what they are trying to make, plus how much time they can spend on a single artwork.
for example, if you are doing "cell shading" cartoon work you don't need this, and usually, distant objects don't need it either.
With myself, often I am "learning" with each scene I make and want to move onto the next one with what I've now learned, and don't want to spend months making one perfect picture. Plus of course, real life limits time for all of us.

Model makers often do not "chamfer" the edge of models because it adds a great deal of poylgons, which makes them use more resources, more bandwidth to download, etc.
In games, to get aorund this, the designers use several versions of the same model, with different "levels of Detail" (LOD), so as you approach, say, a house, the model a mile away has only a few polygons, at 200 yards it's swapped out for one with more detail, and up close one with a lot of detail.

The detail in games often comes from using "Normal Maps" to push polygons out of the model using a 2D image to keep reosurce useage down, as a fully detailed model with every little bit modelled and built into it would require a LOT more resources than one using a simpler model base with Normal Mapping which just pushes detail out based on one special image.

With recent versions of Vue, you can use displacement and Normal maps, to add details to models.
Vue Infinite and some other versions, can export the UVMap of a model, this you can then use as a basis for making or tweaking a displacement or Normal map ot add features you wish.
With a bit of work, you could make the perfectly straight, unrealisic corners of a building, more rounded and believable by doing this by making your own custom Displacement or Normal maps.

Another easier way to do this, is to use a "Boolean" to cut off a roudned edge off the corner, Doesn't always work well and means you may have to texture the cut away apart.
You can take a long thin Cube in Vue, then Boolean out a Cylinder from it, leaving a curved "C" shape you can apply to a straight corner, to cut it into a more smooth, rounded shape ;)

The easist way of all, but most difficult IMHO to get right, is simply to paint in details in postwork, in Photoshop or whatever paint application you use.
because models are non-real geometry in 3D space, they can have PERFECT edges which are impossible in real life, real edges always always have some width, which scatters light causing highlights, so knowing this, you can use highlight and shadows etc to paint the illusion of more rounded edges.

For dirt and variation in colour and bump, the simplest method is to just put a dirt material layer over the top of the existing one.
Using a random, fractal based procedural, you can make no two leaves etc look exactly the same!
Generally if you set a texture to WORLD MAPPING, this ensures the difference in position will offset the procedural between each leaf, so none look the same ;)

My free "Dirt material" does this kind of effect, though I have set it to "Object mapping" so folk could use a UVmap to drive it for precision.
Using a UV map of an object, you can make the "dirt" appear only on specific areas, again such as the hem of clothing, or the doorway of a room, deck of a ship, perhaps, or even make footsteps!
In Vue material editor, you link the UVmap greyscale image you make to the Alpha channel of the "Dirt layer", setting where there will be, and will not be, dirt using black, white and greys.

Dirt and grime and wear...aren't always dark smears, again, exposure to wind, sun and friction would leave a doorway more scratched,lighter
the raised surfaces of a door handle will have more reflection and less bump by being worn smooth.
So you need ot uderstand how real objects come to look, just like a painter does.

GLOSSARY:

UVMAP:
3D models can be specially made to have a 2D image projected onto their surface, this "UVMAP" sets out where parts of an image will go on a model.
Using this UVMap, you can make your own textures for the model, including using it to make greyscale maps to drive transparency for where dirt mapbye, or bump maps.
Vue Infinite and Xstream, and I think Complete can export object textures and thus UVMaps.

BUMP MAPS:
Bump maps are an easy way to fake surface depth on a model using 8 bit greyscale or even colour images.
problem is, it's only a "fake", so at the edges of objects you can see it's not really pushing brickwork out, for example. However, it uses less resources than Displacement or Normal Mapping.
If such details were built into the 3dD model itself, the polygon counts would be enormous, and hence, bump mapping, evne if it uses resources, is a lot LESS resources than modelling it would be.
ALso, importantly, bump, displacement and Normal mapping are not permanent, they can be changed at the user's whim!

DISPLACEMENT MAPPING
this is like "super" bump mapping: it really does push the model's surface in or out, adding lots of detail!
However, it requires a LOT more resources than bump mapping as it can hugely increase polygon counts.
Note that like with Bump Mapping, if you only use an 8 bit image this only gives 256 possible values of grey, from black to white, and  that can leave some obvious bands of differing height, like "stair steps".
16 bit images allow for many thousands of shades of grey, but require even more resources as the images have large file sizes comapred to 8 bit and not all paint applications can make them (Photoshop can however)

NORMAL MAPPING:
this is a very advanced form of bump mapping. Like displacement mapping it can push an object's surface out, but also, in varying directions and angles!
The images themselves are very peculiar blue-purple things that take some work to get used to.
Again, they can cause huge increases in resource useges, but can give incredible detail work and still use less resources than modelling the object in high detail would.

My Layered Dirt Mpa material for VUe
http://www.silverblades-suitcase.com/vue_mats/Steves_Layered_Dirt_V8.zip

My tutorial on Poser clothing showing how ot add wear, grime etc and fix clothes "poking through"
http://www.silverblades-suitcase.com/tutorials/htm/55.html

Putting dirt on the bottom of rocks or walls:
http://www.silverblades-suitcase.com/tutorials/htm/28.html

Weathering 3D materials
http://www.silverblades-suitcase.com/tutorials/htm/24.html

Optimizing Poser Imports:
http://www.silverblades-suitcase.com/tutorials/htm/24.html

Making UVMapps with UVMapper:
http://www.silverblades-suitcase.com/tutorials/htm/14.html

Overlaying Materials for stians etc (old tutorial, "Layers" in more recent versions of Vue are btter than Mixed materials in general)
http://www.silverblades-suitcase.com/tutorials/htm/5.html

Some good points there Silverblade.

Could I add that one should be satisfied with your work at each stage (modeling, UVs, Texture) and don't move on untill you are

Attached Link: Rollmops

When my Art PC is fixed and I'm feeling bit better I'll make up a tutorial on this with images to explain it more :)

can bryce7 do Booleans of imported models? if so that's easy way to fix the sharp edges on say, buildings, as noted, take an elongated cuve, boolean out a long cylinder from it, to get a curve shape you cna boolean straight edges off into rounded corners instead.

Silver is absolutely right. Not to blow my own trumpet, but I did these two versions of the same pic. I think they give folks a bit of an example of what Silver is talking about.

I did the first one and then realised that it was just way too 'clean' and did not resemble the original Gieger piece I was 'copying'.

http://www.renderosity.com/mod/gallery/index.php?image_id=1093120&user_id=122226&np&np

I then worked on making it 'dirty' and 'used'......

http://www.renderosity.com/mod/gallery/index.php?image_id=1093621&user_id=122226&np&np

I hope this helps.

Bryster

yeah that's a great example of it! :) takes a fair bit of the "CGI" out.

hey I don't know if bryce 7 can do it yet, but having materials as LAYERS, ie kind of like Photoshop but controlled by alpha channels (liek transparency maps), is awesome, you should push that through as an idea for DAZ to work on if Bryce does't have it yet, makes addign dirt, decals etc so easy!

If health recovers may try Bryce again if only for nostalgia, I may preffer another app, but I started with Bryce and still think it's a bloody good app :)

Bryce does/can use Alpha/transparency maps. In others words if you have a dirt layer you can mix it with a clean mat.

Bryce 7 has new curvature filters and render options in the mat lab and the DTE to get the "dirt" effect if you will, the way its set up now is so you don't have to make a bunch of channels to get the effect, also displacement mapping using images or procedural textures is implemented into the mat lab now below the bump slider. And Bryce has always been able to do booleans on imported meshes, Edit>set solid when boolean rendering.

Thanks guys!