Google Earth to Sketchup Video Tutorial

5 02 2014

I’ve created my first video tutorial this evening.  Recently I’ve found myself needed to create a number of very quick context models for various project sites.  Fortunately for me, I remembered a technique that I learned a while ago, using buildings from Google Earth (and more specifically the Google 3d warehouse) to bring into sketchup.  I know that a number of you have heard my rants on sketchup and for those who haven’t I’m sure it’ll come up in the future.  Needless to say, I’m not typically a sketchup user, but I do have to say, this technique is VERY helpful.  Because of the past connection between Google, Google Earth, and (formerly) Google Sketchup, this technique starts and is fundamentally rooted in Sketchup.  Don’t worry fellow Rhino and 3D Max users, the next tutorial will talk about how to pull this out of sketchup and into another program.

Check out my video on youtube:

or Screencast.com

Hopefully this helps!  As always, please leave a comment or let me know if there’s anything that needs clarification.





DPI and Output Size – what you need to know

4 02 2012

Ok, so I know that I promised I’d come up with a post about how to pull all the previous discussed techniques together, and trust me, I will.  However a conversation at the office yesterday arose and I thought it’d be a really good thing to post about…output size and how large should we be saving our images.

Keys to remember:

1)   It’s all about pixels!

Remember this, as it’s very important and the common factor between most of what we’ll talk about for the rest of the post.

2)  There’s going to need to be a bit of math, but trust me…it’s not that hard.

Go back to your days of Algebra I and you’ll be fine.  We’ll be using the equation DPI * Inches = Pixels.  From this equation, if we have 2 of the 3 variables, we can always solve for the other.  More on this to come later.

3)  It’s about the distance at which the object is going to be seen.

The human eye can differentiate pixels at about 120-150 dpi when being held and read in one’s hand.  As you step further away, less definition is needed.  Think about those various pixelated images that when you get close you see they are a montage of small pictures, but when you stand back appear to be one image.  This is exactly the same principle.

Image courtesy of Sabri Farouki at http://sabrifarouki.com

Also, as you get older and are in lower light, you will be able to differentiate less dpi.  The other thing to keep in mind is that vector based information done in a raster based program will show effects dependent on the dpi.  The best example of this is text in Photoshop.  While working with a 72 dpi image, the text will look fairly pixelated and jagged.  The reason is because the linework of the font has to fit within the pixel.  For this reason, I’d suggest working with text in either Indesign or Illustrator.  Working in Photoshop will force you to use a higher resolution (200dpi-300 dpi) because of the text issue which will force you to render or use a larger image, negating the speed of using the smaller rendering or image.  See below for an example of the pixelated text and how the text needs to fit within a pixel as opposed to remaining vector based.

Text in Photoshop - click to see full size

4)  What is the output media going to be?  Print? Video? Billboard?

Typical video/computer/projectors use a 72 dpi standard.  HD video uses 1920 px X 1080 px (hence your tv is a 1080).  The computer monitor or projector will have their own resolution.  The laptop I’m writing this on for example is 1400 x  900 px.   As previously stated, printed material for hand outs should be min. 150 dpi and then printed presentation boards could go down to 100 dpi.  If you’re looking to create a billboard or rendering for site signage, you can get down to 50-25 dpi even.  I have even seen freeway billboard images that get down to 5 dpi and look fine from 100′ away.

 

5)  Think about what you are going to use the image for, both now and in the future.

If you need it at one size now, will you need it at a larger size for print/projection/etc later?  It’s always easier to reduce the file and reduce than it is to enlarge.  The reason for this is a bit technical but essentially, the algorithms that a program uses to “guess” what color a pixel needs to be when it’s enlarged struggle to execute effectively as they are asked to enlarge and compute more and more pixels.  Therefore if you’re asking Photoshop to increase an image 110%, it might do a decent job.  If you ask to increase that image 200% however, you’ll notice the image struggles to create accurate results.  Essentially, the enlargements that you see on NCIS, CSI, etc don’t really exist…sorry to burst your bubble!

Yes, there are ways that you can enlarge an image in Photoshop using “Resample Image” selection but remember, this still is an algorithm calculating it’s best guess as to what the color of the image should be.

The software will guess what color goes in each red square based on the color and surrounding colors from the white squares.

Just remember that these algorithms can cause problems if you reduce and image just to enlarge it again.  See what I mean below as I take an image, reduce it and then enlarge it to it’s original size.  the problem is that when going from small to large, it looks blurry or more pixelated because the computer is guessing what the pixel color should be.

Original Image Size - click to see full size

File reduced to 520 pixels - click for full size

Reduced file enlarged again to 1040 px - click to see full size

Workflow:

Now when you are working about to create a rendering, it starts off by figuring out what size the rendering needs to be.  For example, let’s say I need a rendering for a hand out.  This tells me that I’ll need at minimum 150dpi.  Go back to our pixel equation from above and we can calculate that our output should be 1650 pixels (150 dpi X 11 inches) by 2550 pixels (150 dpi X 17 inches).  What this also tells me is that with the same output or image, I can crop the image to fit my 1400×900 pixel laptop screen.

You don’t want to create an output too much larger than necessary because time is always going to be an issue.  Remember doubling the output isn’t actually doubling it.  A 11×17 image at 300dpi is actually 4 times (twice the pixels in height times twice the pixels in width)  the pixels as an 11×17 image at 150 dpi.  This means that it will take 4 times longer to render the 300 dpi image than the 150 dpi image!

White square = 1 px @ 150 dpi, Red Square = 1 px @ 300dpi

Again, because it’s easier to reduce rather than enlarge, I can reduce that same image to 8.5×11 easier than enlarge it to 18×24.  However, if I needed that image on a board that would be seen from 5-10 feet away, I know I can get away with about 100dpi which would allow me to enlarge the image to 16.5 inches (1650 pixels/100dpi) by 25.5 inches (2550 pixels/100dpi).

You can now understand how with a decent knowledge of this information a lot of time can be saved without reducing the quality of the image.  I know this was a bit off topic, but hope it helped.





Vray Material Tutorial – Part 1

4 08 2011

So after a much longer than expected hiatus from the blog world, I have finally begun to break down the mystery of Vray materials for my faithful followers!  I have been excited to receive comments and questions on my previous tutorial on lighting in Vray and hope that this tutorial will promote further discussions on various techniques and uses of this very powerful render engine.

I have been asked a few times why I’m creating this line of tutorials and giving away some “trade secrets”.  The answer is quite simple.  I feel that these are not actually secrets, but instead it is my responsibility to spread the knowledge that I have gained with those who are trying to learn the program.  It wasn’t that long ago (although some days it feels like it) that I was new to the digital visualization industry.  Without the help of others, I wouldn’t be where I am today, nor would I have the skill set that I feel fortunate enough to share with others.  My honest hope is that sharing my knoweldge is as influential on others as some have been on me.

And now on to the learning!

Introduction:

For the purposes of this tutorial, I am using a very simplistic scene that utilizes the Vray Express Scene as a background.  This can be found if you have the “Vray Express” toolbar installed under the “Vray Express. Vray Express Studio Scenes” button.  To get to this, right click on any empty portion of the tool bar area and scroll to the proper check box and ensure that it’s checked.  A ewtoolbar should pop up and you can select the appropriate size studio scene for this tutorial.  This is a handy way to create proper lighting and ground/background plane for your scene.

I have created a few solid objects that we will use throughout this tutorial.  For illustrative purposes, I have used various shapes as the light and materials will all interact differently depending on the shapes.  For now I have created all these objects on the same layer, but we will change this soon.

Basic Scene Set Up

Material Editor:

The first step that we will take is to open the Vray Material Editor.  To do this, either select the material editor tool bar or go to the Vray drop down and select “Material Editor”.

Material Editor Selections

This will open the Material Editor as shown below.  This is the interface we will use to create, manipulate, and apply the materials that we create to objects in the scene.

As you can see, we already have a few materials in our workspace.  The Default_VRay_Material is a material that we will work with and begin to manipulate.  The Floor material is a material that was automatically created for us because we are using the Studio Scene as a background.  This material is automatically assigned to our ground/background plane.  If we wanted, we could also manipulate this (but I won’t).  Because I’m an organizational freak when it comes to my scenes, I will immediately rename this Default_Vray_Material to something that is more appropriate.  To do this, right click on the name of the material that you want to rename and select the Rename option.  Because we’re going to begin by working simply with the Diffuse layer, I will change the name to DiffuseMaterial.

Rename to DiffuseMaterial

Diffuse Layer:

We will now work with Diffuse Layer.  The best way I’ve found to think of this layer is the general color that you’d describe a material to someone.  If I were to look at an orange sphere, I wouldn’t describe it as orange, but peach at the edges…I’d simply describe it as orange.  So with that being said, let’s change the color of our material to orange!  Under the Diffuse tab, select the color swatch next to the word “Color” and select your favorite shade of orange.

Change the Diffuse Color to Orange

When you are finished click “OK”.  We will then update the preview of this material by selecting the “Update Preview” button under the preview.  Now our preview sphere is orange!

A quick test render shows that the objects in our scene haven’t changed though.

“Why is this?” you will (hopefully) ask yourself.  The answer is very simple!  You haven’t told the computer which objects this material should be assigned to!  We will do that now.  There are fundamentally two ways to assign a material to an object, on a per object basis and on a per layer basis.  For the most part, I like to assign most materials by layers.  This makes it easy for ensuring that all objects on a layer are assigned the same material.  For example, if I’m creating an exterior architectural rendering where I want ALL my exterior walls to be brick, this technique saves me time from having to select each individual wall to ensure that the material is assigned to those walls.  However, there are certain times that assigning a material on a per object basis is more advantageous.  Let’s say I’m doing an interior architectural rendering where I have 5 magazines laying on a coffee table.  I want each magazine object to be the cover of a different magazine and therefore would rather assign each magazine on a per object basis (so I don’t have to create 5 seperate layers for what is essentially the same object).  At the end of the day, the choice is yours, I only suggest you think through the ramifications of your selection of these techniques.

There are also various ways to assign a material to a layer or object.  For now, we will right click the DiffuseMaterial name and select “Apply Material to Layer(s)”.

Apply Material to Layer

This will open a dialogue box that allows you to check which layers you wish to assign that material.  For now, select the layer that you created the objects on and re-render.

This seems like as good of a place as any for me to interject with a tip that will make you question your grasp of physics, and color.  White isn’t REALLY white.  “What does that mean?  Matt have you gone mental?”, you may ask yourself.  Rest assured, I haven’t.  There are actually people who have done experiments to show that that 8.5×11 piece of white paper that you are looking at isn’t really white (atleast in the computer RGB value sense of the word).  Because of the way that materials are made, and the way that light interacts with them the white that you perceive is actually only about 90-95% (depending on who you ask) true white.  This means that you should never create anything in the diffuse color that has an RGB value of 255, instead you should take 90-95% of that number which is 230-242.  Anything over that will simply slow your renderings down because the computer is calculating extreme values that aren’t perceptible and don’t occur in real life.  Some visualization artist bring this number down to 75% (RGB value of 192).  That’s just some food for thought…back to the lesson and adding transparency!

The previous render is beginning to look good, but perhaps we want to add a bit of transparency to our objects.  It’s relatively easy.  We’ll go back to the material editor and select our DiffuseMaterial.  This time, instead of selecting the color swatch next to the “Transparency” text.

Select Transparency Color

Unlike the Diffuse Color swatch, the Transparency swatch works on a grey scale.  When this color is 100% black (RGB value 0), it’s 100% opaque.  When it’s 100% white (RGB 255…yes, it’s ok to use in cases that aren’t the diffuse color), it’s 100% transparent.  If I wanted the material to be 50% transparent, I would change the transparency swatch to be medium grey (RGB value 128).  Let’s try this and see what happens.

50 % transparent - RGB value of 128

Click ok, and update the preview.  Notice how the material appears to have some transparency, as we can partially see the checker background behind the sphere.

Preview Update

Let’s re-render our scene and see what happens…

Notice that our objects appear to have transparency and we didn’t have to re-assign the material to the layer or objects!  Depending on where you created the objects, you may notice the bottom surfaces of some objects appear to have some splotchiness (called artifacts).  The reason for this is that in the computer world those faces are sharing the exact same space as the ground plane.  If this really bothers you for these tests, move your objects up slightly (1/4″ or so) and re-render…the artifacts are magically gone!

Move objects vertically and No Artifacts!

 Using Maps:

Thus far, things have been fairly straightforward and as a result fairly easy.  We can change the color of our objects and add transparency.  Not everything in the world is simply one color however.  At times, we may want to map an existing image, onto an object to use it as our color.  Bricks are a great example of this.  Perhaps I want these objects to be bricks and I’ve got a nice image of bricks (such as the one below) that I would like these objects to be without modeling each individual brick and grout line.  Well thankfully we don’t have to waste all that time needlessly modelling.  We can use what’s called a map.

Let’s go back to the diffuse tab and change the transparency color swatch back to 100% black to make our objects completely opaque again.  Next select the lowercase “m” between the diffuse color swatch and the Transparency text.

This will bring up the Texture Editor dialogue box that will allow us to utilize the brick image as our diffuse output.  In the texture editor, change the type from “None” to “Bitmap”.  Even though we aren’t using an actual .bmp bitmap, it’s ok…in this case bitmap is used as a general term for any image type (.jpeg, .bmp, .png, etc.).  Once this is done, select the lowercase m (a lowercase m means there is no map assigned, upper case M means a map is assigned).  Navigate through the file structure to your brick (or other) image that you would like to use.

Change Type to "Bitmap" then select the Bitmap File Map button

The lowercase m is now changed to an uppercase M, showing that the map is now applied.  Select Apply to exit the Texture Editor.  Notice again that the Diffuse color map that was lowercase is now an uppercase M.  We’ll update the preview and see that the sphere now shows our brick image mapped to it!  Note: when the diffuse map is used, the diffuse color swatch no longer has any effect on the output!

A quick re-render will show that our objects now have the appearance of the brick image!

Brick Image mapped to objects

Coming soon!

In the next lessons we will discuss:

  • how to use maps to add transparency for things like a chain-lined fence or brick screen walls with holes
  • adding depths to our materials using bump maps
  • adding a reflection layer (giving our object shine or glossiness)
  • adding a refraction layer (mimicking glass, water, or other refractive materials)
  • adding emissive layers ( giving our objects a “glow” to them)
  • different material types (2 sided material, toon material, etc.)
  • importing existing vray materials (creating and organizing material libraries)
  • UVW mapping (controlling the size, scale, and projection of maps such as the brick we’ve just applied)
Look for this next tutorial by the end of the weekend!
As always, let me know if there are any questions or clarifications!

 





Introduction to Vray Part 1 – Lighting

28 04 2011

As it’s getting close to finals in architecture schools across the USA, I felt it was a good idea to create a small tutorial to help all those students pulling their hair out because of rendering issues.  In this tutorial, I hope to shed some light (literally) on some of the nuances to my favorite render engine.  This tutorial is based on the course that I taught while I was a student at Washington University from 2008-2010.  I have modeled this scene in Rhino and will be using VRay for Rhino, but rest assured that these are basics that translate across programs, so if you’re using VRay for Sketchup or 3ds Max, the fundamentals are the same, I simply used an existing model I created in Rhino.

I will start with an interior model, with furniture and windows.

The initial model from Rhino

The next major step is to place lights in the scene.  The reason to implement the lights before adding material is simple, with good lighting the materials will fall into their own. Once the lighting is set correctly, you will then have a realistic feeling for what the materials are doing and how they react to subtle changes.  I then add an exterior light to simulate the sun coming in from each window.  To do so, I use the sun tool that comes with Vray for Rhino.  This allows the user to have advanced control over the exact sun angle given a particular time of day and geographic location, or you can manually place the angle of the sun if specifics aren’t important.

The exact location that the sun is placed in the scene doesn’t matter at all because, like in the real world, the sun shoot an infinite number of rays in a parallel direction to each other throughout the entire scene.  It should be noted that this sunlighting system works only when using the Vray Physical Camera in the Camera settings, but I will go more in depth about this later.

The next step is to add rectangular lights at the openings to supplement the sunlight system.  This helps to create additional light as well as add a bit of realism to the scene by focusing more light at the openings, a phenomena that also occurs in nature.  To do so, create a rectangular light that is slightly larger than the opening, ensuring that the light is pointing into the room.

To manipulate the lighting settings for the rectangular lights, select the light and in the properties tab, select the roll down and change it from “Object” to “Light”.  The multiplier value for these rectangular lights will depend on a few factors (camera settings, and size of the light mostly), but a few things to keep in mind, that you should select “light portal”.  This tells the program that it is to be used to supplement the existing light from the exterior, similar to the way a light comes into a window.  We also want to ensure that the light is “invisible”, so we can see through it and see the exterior of our scene. In this case, we don’t need to have the light be double sided because we’re only interested in focusing the light’s energy to the interior of the scene.

Light Multiplier settings:

Light Multiplier Values change intensity of light source

Visible Light vs. Invisible Light Source, notice the intensity doesn’t change:

Visible Light Source vs. Invisible Light Source

One sided light source vs. double sided:

One sided vs. Double sided Light Source

Below is the settings that I used for this scene, but note that your values may need to change depending on your particular scene.

Rectangular Light Properties - careful, these are scene dependent!

To ensure that I’m not getting any material interference, I have added a neutral material to the material override in the vray option settings.  In this case I check the overrride material box under the “Global Switches” tab.

Override Material with color over 128-128-128, a medium grey

In order to allow the light to come through the openings, I must hide the windows in the Rhino model, even if we’ve added a glass material to the windows because the material override will override all materials including the glass.

This seems like a good time to do a test render, but first we must look at some of the other rendering settings in our render options.  The first tab that we should focus on is the Global Switches tab.  We want to ensure that lighting is checked, letting the program know that it needs to calculate the lighting.  We however don’t want to have the Hidden Lights boxed checked because if we hid some lights in the scene, we shouldn’t have those calculate, we just want to see the effect of the lights that are shown in our scene.  We also don’t want to select the Default Lights box because we have placed lights in our scene and want to use only the lights that we have placed and have control over.

Global Switches Tab

The next tab in our options that we should be concerned with is the Camera tab.  Because we are using the sunlight system, we should ensure that the physical camera box is selected.  If we forget to check this box, the scene will be WAY too bright because we’re not allowing the calculations to compensate for the incredible intensity from the sun.  For those who have used a digital SLR camera or a film camera should quickly recognize the controls over the physical camera.  Here you have the ability to control the camera’s shutter speed, the F-stop number, and the film speed.  These three numbers work in conjunction with each other to create how the camera compensates for the exposure of the lighting.  This may take some time to get comfortable with if you have never used a SLR camera before, but the Vray manual has a very through explanation of how each of these controls works.  It can be found at ASGVIS.com under the software and support tab.

Camera Tab

The Output tab allows a user to override the size of the image that they wish to output.  If, for example, I know that I need an image that is 1500 pixels by 800 pixels, this is the place to input that information.  It also allows a user to obtain the aspect ratio from the existing scene for easy scaling, by first selecting the “Get View Aspect”, locking the ratio, and then changing the pixel size.  This is useful if a user wants to ensure what they see on the screen is what is rendered for a given size.  If I set up my scene and like how it looks on my screen, I’ll use this technique and then tell the program that I need a maximum of (for example) 1500 pixels wide.  However if I’m simply doing test renders, the output size isn’t an issue yet.

Output Tab with ability to change rendering size

The Environment tab gives the user the ability to create the environmental lighting (not the direct sunlight, but the light from the sky) and control how it is handled in the scene.  Because we have created a sunlight system, it’s possible to link the position of the sun light to the environmental light.  By linking the two, we will get a reddish light as the sun approaches the horizon as occurs in nature, as the light comes closer to noon, the environmental light will become more blueish.  To link the sunlight position to the environmental lighting, select the little “m” next to the GI (skylight) check box.

Select the little "m" to apply a map

When this is selected, a new Map texture editor pop up will appear.  Change the type from “none” to “Sky”.

Before selecting apply, we must make sure that the program knows which light source we want the sun to be.  Select the button next to “Sun-light source”.  A new pop up menu appears and now allows us to select the sunlight we previously created.  If we leave this at “Default”, we will not create a link between the sun light and the environmental light.  Once we select the proper light, click apply, to get back to the the Vray Texture editor.  Make sure that you unselect the check box next to “Override Sun’s parameters” and finally click “apply”.

We have now created a link between the light from the environment (in this case the sky) and the sun’s position in the sky.  The next option in the environment tab is the Background.  We can follow the same process that we just went through to add a background that matches the sun’s position in the sky, or we can add a background image if we have a jpeg that we want to use as a background.  This can be helpful if we have a site photo, a stock image of a nice sky with some clouds, etc.  Since I am creating an imaginary scene, I’m going to apply the link to the sun’s position as previously mentioned following the same processes.  At the end of this process your Environment tab should look similar to that below.

Completed Environment Tab with mapped GI and Background

The next tab we’ll talk about it the Indirect Illumination tab.  First, ensure that the box under GI is turned on.  The allows the light waves to bounce off of geometry and give reflected light, ensuring that light bounces off the floor and continues to bounce and light the scene.  If this isn’t turned on, the only thing we will see in our scene is the direct light from our light sources which will cause a very harsh and yucky (yes, that’s a technical term) lighting results.  Next we get to select what types of rendering engines we will use.  These deal with the way that the program calculates how the light reacts in our scene.  Some teams way smarter than I am created various algorithms for how light reacts and that’s essentially what we will be selecting.  I won’t go into the boring details of each one right now, but I will tell you that I use the Irradiance Map (IR Map) as the primary engine and the Light Cache (LC) as the secondary engine.  I have found that these two in combination give me the best quality and the lowest render time.

Indirect Illumination tab

For test renders I use the following value under my IR Map tab, in the next tutorial I will further explain what these mean and how to control quality output:

IR Map settings

And the following are the typical LC settings I use for test renders, please note depending on the scene the subdivs can be between 100 (quicker, less accurate) and 500 for tests:

LC settings - note: subdivs can vary between 100 and 500 for tests

We can now run a quick test render to ensure that our exterior lighting is working correctly and with a short render time we get decent results.  It’s a bit grainy, but we will take care of that later.  At this point, we’re strictly focusing on the lighting.  Notice the blueish tint that we are getting on the floor close to the windows as a result of linking the environmental lighting to the sun’s position.  This is what we might expect in nature.

Test Quality Rendering - Exterior Lights Only (16.6 second render time)

We can now continue adding lights to our scene.  In the wall sconces, I prefer to add double sided rectangular lights because 1) they are faster at render time and 2) that’s the way the light actually comes out of a sconce like this, primarily from the top and bottom (yes, I know the shade will glow, but we’ll take care of that in the next lesson when we talk about materials).  Finally because there is a door opening and I want to add a bit of life to the scene, I add a rectangular light at the ceiling level of the adjacent room, giving a slight amount of light added to the room that our scene is focused on.  When all is said and done, we have the images below:

Test Quality Rendering - all lights (27 second render time)

Medium Quality Rendering - all Lights (1 min 29.3 seconds)

Come back soon to learn how to add materials to create this rendering:

Final Rendering with Materials