I don’t know why I haven’t realized it before.
I was texturing a model of a building (as described in the real world scale uvw tutorial) and something didn’t work as expected. I had a 25×25 cm textures that simply looked huge when applied to the model.

I double checked and triple checked everything but still the texture mapping was wrong. Finally I noticed that the size of the gizmo of the uvw map modifier wasn’t correct compared to the building. At that point I realized that the building was modeled in a different scale, than it was scaled using the scale tool to match the real world scale.

In order to better understand what the problem is, open 3ds max and create a simple 10 cm radius sphere. Now clone it, and scale the cloned object using the scale tool. Take a look at the radius of each one. They are both 10 cm even though one is obviously bigger.
The same happens with modifiers, in my case the uvw map. Even though the size was set to 25×25 it looked nothing like that.

Needless to say that you should model everything at real life dimensions, but if you find must work on a model that was scaled here is the solution:

Select the objects that you need to “repair”, go to the utilities tab select “reset xform” and click “reset selected”.

I hope this was helpful.

So what does it actually do?
The main idea is that you can edit a dwg file without any license or software installed. All you need is a web-browser and the latest flash player from adobe.
This makes it accessible from anywhere and by anyone you share it with.

And speaking of sharing, you can actually co-edit a drawing with a colleague or a client in real time. Everything is done directly online so the files are not actually transferred from one user to another. This means that you can conduct online meetings with unlimited participants, make revision mark-ups, etc.
There is also a widget that let’s you explore all the changes done in a revision meeting so you won’t miss anything.

I see this application particularly useful for cad drafting studios and architecture offices, especially for internal meetings.

However, I don’t see it being used for architectural visualization at the moment… but I am certain the way technology evolves, in the future we will see something similar for 3D models.

In the meantime, you can watch the video bellow to see a more in depth presentation or check out the official site for project butterfly.

http://www.cgtextures.com/
Probably the most notorious site where you can find tons of free textures of various categories.

http://www.mayang.com/textures/
One of the oldest textures sites on the internet.

http://www.marvamarble.com/Product-Index.htm?u
A very comprehensive site where you can find tons of marble and stones textures.

http://vyonyx.com/category/down/cutout-people/
Probably the best site for free people cutouts; each file comes in psd format so you can easily composite it on your rendering.

http://downloadarea.margraf.it/
A great site for marble textures. Registration is required.

http://free-textures.got3d.com/natural/free-grunge-textures/index.html
Several categories, but I especially like the grunge textures.

http://www.michalkotek.com/download.html
A nice collection of textures and a set of trees cutouts.

http://www.defcon-x.de/c4d/textures
Several types of wood textures

http://free3dstextures.com/
Most of the textures available from this site require additional work in order to make them tileable, but the resolution and the sharpness are great.

http://texturez.com/
Another great site with large variety of textures.

Again, this isn’t meant to be the most comprehensive list, but if you think that I have missed something important, feel free to post a link in the comments section.

Before we begin we need to setup the lwf.
Go to “Customize”, “Preferences” and click the “gamma and lut” tab.
Check “Enable gamma /lut correction”, type 2.2 in the field next to “Gamma”.
Under “Materials and Colors” check both “Affect Color Selectors” and “Affect Material Editor”.

Don’t forget that for every texture that you use you need to override it’s gamma like in the screenshot bellow:

If you need a more in depth explanation regarding linear workflow, check out my lwf tutorial that I have posted some time ago. However, the steps above pretty much cover the essential.

1)    Click the “create” button and select “cameras”. From the drop down menu select “vray” and click on “vray physical camera”. You can now create and place the camera wherever you want in the scene.
2)    Now we will create the sun. Click again on “create” and choose “lights”. Again, from the drop down menu select vray and click on Vray sun. You can now place the sun and it’s target in your scene.
When you will be asked if you would like to “automatically add a Vray Sky environment map”, click “yes”.

The position of the sun source is directly related to the time of the day. Bellow are 2 examples of renderings with different sun positions (while keeping the rest of the settings identical).

VraySun parameters

1) -turbidity
This parameter affects the color of the sky and overall atmosphere in a way the dust affects atmosphere. A higher turbidity value simulates a larger amount of dust and makes the rendering look more yellowish. See examples bellow:

2)  -ozone – ranges from 0 to 1. Lower values are supposed to make the sunlight look more orange, while higher values should make it bluish. I always prefer to leave this as default.

3) -vray sun size multiplier – a value of “0” produces very sharp shadows, while higher values makes them softer.

4) -shadow subdivisions – if you are using a higher value for the vray sun size you will need to increase the shadow subdivisions as well, otherwise the samples will be visible.

5) -Intensity multiplier – needless to say that higher values results in higher sunlight intensity

Having this said, the settings that I usually use for creating a day rendering are:
-intensity 1
-turbidity 4
-size multiplier 5
-shadow subdivisions 9

If you don’t like the vray physical camera, you can use a standard one as well, but you need to decrease the intensity to somewhere around 0.01

Bellow is a rendering that was done using the settings above.

As you can see, at the moment it looks a bit dark and washed out. You can either play with the curve in vray virtual frame buffer, or start tweaking the vray camera settings.

Vray camera parameters
I always prefer to further adjust the image from the vray camera parameters.
There are 3 main parameters that affect the lighting/atmosphere: F-number, shutter speed, and film speed.

1) F-number
This parameter determines the width of the camera aperture and therefore it affects exposure. Higher values produce darker images, while lower values brightens the images

2)Shutter speed
This parameter determines the amount of time the film is exposed to the light. It is calculated in “inverse seconds” therefore higher values produce darker images.

3)    Film speed
This parameter determines how sensitive the film is to the light. Higher values produce lighter images, but the downside is that the higher the sensibility the more “grainy” the image will look.
For daylight exterior renderings it is recommended to keep this at 100.

There are several other parameters that you can touch (like custom white balance, vignetting, etc) but you can have more control if you do this in photoshop.

In conclusion, even though there are no “universal settings” for the vray camera, whenever I do an exterior daylight rendering I start with the following settings, and depending on the scene I may need to tweak them a little further.

F-number – 7
Shutter speed – 120
Film speed – 100
Rest of the parameters – default.

Bellow is the rendering done using these parameters.

In the next part of this tutorial we will talk about image based lighting, so stay tuned.