3ds Max and Revit Interoperability - Part 09 - Day Scene Lighting

By
-
Login to Follow
-
Industry
  • Design Visualization
Subject
  • 2015
  • Interoperability
Products
  • 3ds Max
Skill Level
  • Intermediate
Duration
10 min

3ds Max and Revit Interoperability - Part 09 - Day Scene Lighting

In this tutorial, you experiment with a Daytime lighting scenario based on an exported Revit scene. You test out the default parameters and then learn to improve on them.

Notes

  • Recorded in: 3ds Max 2015
  • This tutorial is intended for use with 3ds Max version 2015 or higher.

Transcript

00:00:06 --> 00:00:11
Now that you have two FBX files to test out, you'll start by experimenting with a day scene.

00:00:12 --> 00:00:15
In 3ds Max, reset your scene.

00:00:15 --> 00:00:23
Import and link the day scene you created earlier or you can use the provided file named room_day.fbx to that effect.

00:00:25 --> 00:00:30
Use the Combine by Family Type method as you have done before and attach the file.

00:00:30 --> 00:00:36
Because Revit always exports a Daylight System, you are prompted to use Exposure Control.

00:00:36 --> 00:00:41
This is needed to compensate for the brightness of the sun, much like with a real-world camera.

00:00:42 --> 00:00:47
The default Exposure Value is set to 15. It is a good starting point for daytime rendering.

00:00:48 --> 00:00:51
Click Yes to proceed; the scene gets loaded.

00:00:52 --> 00:00:58
Zoom out and take a look at your scene. Note the presence of the Exterior camera and that of the Daylight System.

00:00:58 --> 00:01:02
Click an empty point in the viewport to deselect all objects.

00:01:02 --> 00:01:07
If you look closely, you'll notice that the artificial lights inside the room are shown in black.

00:01:07 --> 00:01:10
This is actually an indication they are disabled.

00:01:11 --> 00:01:14
To make it easier to see inside, you can hide the curtain wall.

00:01:15 --> 00:01:21
This can be done by selecting its components in the viewport and then right-clicking and choosing Hide Selected.

00:01:21 --> 00:01:24
Another easy way is through the Scene Explorer.

00:01:30 --> 00:01:37
Sure enough, if you were to select any interior light and check its parameters in the Modify panel, you can see that it is Inactive.

00:01:38 --> 00:01:40
That's fine for a day scene.

00:01:40 --> 00:01:48
The Daylight System on the other hand is certainly active and is made of a direct light source or Sunlight simulating the sun,

00:01:48 --> 00:01:53
and a global source or Skylight simulating earth's atmosphere.

00:01:53 --> 00:02:00
Go to the Motion panel and notice that the time of day is set to 14:00 or 2pm as specified in Revit.

00:02:01 --> 00:02:08
If you were to make changes to the time of day or the North Direction, there is not much feedback in the viewport.

00:02:08 --> 00:02:13
This is because the viewport is set to Shaded mode by default in 3ds Max Design.

00:02:13 --> 00:02:16
You can click that label and switch the mode to Realistic.

00:02:17 --> 00:02:21
Still, not much change when you edit the Daylight's parameters.

00:02:22 --> 00:02:27
You may need to disable Adaptive Degradation depending on system performance.

00:02:31 --> 00:02:38
Click the Realistic label again and choose Lighting and Shadows > Illuminate with Scene Lights.

00:02:38 --> 00:02:41
The viewport shading is now affected by the lights in the scene.

00:02:42 --> 00:02:46
Now try to change the North Direction and see the feedback in the viewport.

00:02:47 --> 00:02:50
Settle for a 265-degree angle.

00:02:51 --> 00:02:54
Now press C to set the viewport to display the camera viewpoint.

00:02:55 --> 00:03:00
Do a test render. Not bad, but we can still tweak it a little bit.

00:03:01 --> 00:03:03
You can see the effect of direct sunlight and shadows.

00:03:04 --> 00:03:09
You can also see the effect of global lighting as it illuminates the surroundings and the inside of the room.

00:03:09 --> 00:03:11
This requires tweaking as well.

00:03:11 --> 00:03:17
Notice also the background, as it shows a sky with few clouds as specified in Revit.

00:03:18 --> 00:03:26
Let's see how we can make things better: First, let's do the same test render in higher resolution. This will make it easier to see detail.

00:03:27 --> 00:03:33
Click the Render Setup icon on the render window. It can also be accessed from the main toolbar.

00:03:33 --> 00:03:39
Set the Output Size to HDTV. This will result in a nice 16x9 aspect ratio.

00:03:40 --> 00:03:46
Choose a preset dimension or type in a value. For this movie, I'll use 960x540.

00:03:47 --> 00:03:49
Dismiss the dialog and test render again.

00:03:50 --> 00:03:56
In general, the rendering is still a bit dark. You'll need to adjust the Exposure Value a little bit.

00:03:56 --> 00:04:00
Click the Environment icon to access that dialog.

00:04:00 --> 00:04:04
Set the EV value to 14 and try again.

00:04:08 --> 00:04:14
This is better, overall the scene is brighter and we can make out the inside of the room.

00:04:14 --> 00:04:17
The clouds in the background are a little less visible though.

00:04:18 --> 00:04:24
The clouds and the background for that matter are part of a special map called mr Physical Sky.

00:04:24 --> 00:04:30
This usually gets defined when you create a Daylight System, including when you import it from Revit.

00:04:30 --> 00:04:39
So, in essence, a Daylight System is really made of three components: a Sun, a Skylight and a background in the form of the mr Physical Sky map.

00:04:40 --> 00:04:43
The reason I mention this is because the three work together.

00:04:44 --> 00:04:49
Typically all three should be enabled or disabled together for the scene to work well.

00:04:49 --> 00:04:52
More on that when we test the night render scenario.

00:04:53 --> 00:04:58
For now, to make the clouds more visible, open the Material Editor.

00:04:59 --> 00:05:05
Drag the mr Physical Sky map from the Environment dialog into the Material Editor as an instance.

00:05:06 --> 00:05:11
Double click the clouds map node and set the brightness slider to about 20.

00:05:14 --> 00:05:18
Test render the scene again. The clouds are now more visible.

00:05:19 --> 00:05:26
Do not go overboard with this slider, too high a value usually yields unexpected and unwanted results.

00:05:31 --> 00:05:35
As mentioned a second ago, the inside is still a little dark.

00:05:35 --> 00:05:40
If the building was meant to be viewed from the outside only, you would be fine with this setup.

00:05:40 --> 00:05:47
But if the building is meant to be open or transparent (so we can peek inside), then you need to do some extra work.

00:05:47 --> 00:05:50
There are many ways to improve the rendering solution:

00:05:50 --> 00:05:58
First, you can improve the quality of the rendering by increasing the Final Gather precision and the number of FG Bounces.

00:05:58 --> 00:06:03
Final Gather Precision increases the number of rays needed to calculate the solution,

00:06:03 --> 00:06:10
while FG Bounces defines the number of times these rays bounce off surfaces to add to the global illumination solution.

00:06:11 --> 00:06:18
Keep in mind that while this can give you some promising results, it can also increase rendering time exponentially.

00:06:18 --> 00:06:24
The same scene that took 15 seconds to render a moment ago,

00:06:30 --> 00:06:34
is now taking about 1m20s, and this is a very simple scene.

00:06:35 --> 00:06:43
Personally, I always try to look for ways to keep rendering time at a minimum, even if I have to rely on "non-physically accurate" methods.

00:06:43 --> 00:06:48
One of my favorite methods is to use a light source for Ambient Lighting only.

00:06:52 --> 00:06:56
Create an Omni light which is the same as a point light anywhere in the scene.

00:06:59 --> 00:07:07
Use the Move tool and the Transform Type-ins to relocate it to 0,0,0. This is essential for this method to work.

00:07:08 --> 00:07:16
In the Modify panel, go to Advanced Effects and ensure the light works in Ambient Only mode. That's all you need it for.

00:07:17 --> 00:07:22
Because an omni light is not physically accurate, you'll need to fiddle with its parameters.

00:07:22 --> 00:07:27
This is especially true when you use it in combination with a Daylight System and Exposure control.

00:07:28 --> 00:07:32
Currently, it doesn't havet much effect on the scene, if any.

00:07:33 --> 00:07:40
In the Modify panel, set the light's Multiplier value to about 3000. You can experiment with this if you want.

00:07:41 --> 00:07:46
Test render again. The inside is brighter but now appears a bit washed out.

00:07:46 --> 00:07:51
To bring more shadows where surfaces intersect, you'll use Ambient Occlusion.

00:07:51 --> 00:07:56
This is a process invented by ILM and often referred to as a "dirt map".

00:07:57 --> 00:08:03
In effect, it darkens areas where surfaces intersect, in this case mostly the walls and floors.

00:08:04 --> 00:08:14
With the light still selected, click the Projector Map button and set it to use an Ambient/Reflective Occlusion shader from the mental ray maps list.

00:08:18 --> 00:08:24
A test render at this time takes you back to the original look but that's only because you need to adjust the Ambient Occlusion shader.

00:08:26 --> 00:08:31
Drag the Ambient Occlusion map to the material editor as an instance.

00:08:33 --> 00:08:39
Double-click it to view its parameters: at this point, you're really only interested in the Max Distance value.

00:08:40 --> 00:08:45
You want to set a value here to tell 3ds Max how far to look for intersecting surfaces.

00:08:46 --> 00:08:49
A value of 0 looks to infinity and is not recommended.

00:08:49 --> 00:08:52
Set it to about 3 or 4 feet,

00:08:56 --> 00:08:58
and test render again.

00:08:58 --> 00:09:06
This is much better and still rendering in the 15-second range, so this method doesn't penalize rendering time much.

00:09:07 --> 00:09:12
You can also see how much nicer a rendering with AO is if compared to one without.

00:09:13 --> 00:09:20
Now that you've taken a look at a daytime scene and how to set it up, you will next look at defining a night scene.

00:09:20 --> 00:09:22
This is what you do in the next movie.
Posted By
Tags
  • 3ds Max
  • 2015
  • Interoperability
0 Comments
To post a comment please login or register
*Save $66 per month on Autodesk's Suggested Retail Price (SRP) when purchasing 1 year term 3ds Max or Maya subscription.