One of the best parts of computer graphics is the ability to quickly and easily set up realistic lighting scenarios for subjects, without having to rely on expensive studio lighting or natural lighting to reach the perfect setup. By using HDRI lighting maps and some quality textures, it is possible to achieve photorealistic results of a subject.
In this tutorial, you’ll learn how to set up an HDRI map in an automotive scene, and then apply some textures to the background and the car model to achieve a beautifully realistic result. You’ll walk away with the workflow that you can apply to various situations and lighting for your own models.
Let’s get started!
Tools Used:
- Autodesk Maya
- Photoshop
- Mental Ray
- Pre-Made Car Model from Evermotion.org
Final Image Preview:
Here’s a quick look at the final image result. The car model is from Evermotion, but the rest of the scene we’ll be creating in this tutorial.
The Setup
Assuming you already have your car model imported into the scene, create two planes – One as the ground and other as a wall behind the car.
At this point, it is important to setup a Shot Camera. click on Panels > Perspective > New
This sets up a new perspective camera.
Set a view and click on View in the viewport and click on “select camera”
In the camera properties, change the name of the camera from persp1 to ShotCam and change the Focal Length to 55. I usually feel that the default value 35 generally gives a more CG feel to the final render.
Once you have the view set, go back to the perspective camera.
The Environment
Go to your mental ray render settings. Click on Indirect Lighting and under Environment click on Create next to Image Based Lighting. This will create the mental ray Image Based Lighting sphere around your scene.
Load up a HDRI image by going into the mentalrayIblShape node properties (select the sphere and press Ctrl+A).
Now, turn on Hardware Texturing by going into the Shading menu in the Viewport and clicking on Hardware Texturing and you will see the HDRI applied to the sphere in the Viewport.
NOTE : You can change the mapping mode to Angular if you notice some weird transformation happening.
Now, because this is a nice sunset HDRI, we will use the HDRI itself as our main source of light.
Position the IBL Sphere in such a way that the sun is directly in front of your car model.
We are ready to do our first test render but before that, let’s set up some settings for the test render.
Go into your render settings and under the Common tab, go to the bottom and uncheck Enable Default Light under Render Options.
Go to the Quality tab. Set the sampling mode to Adaptive Sampling > Min Sample Level = -1 > Max Sample Level = 1
Go to Indirect Lighting tab and Turn on Final Gather and leave everything to default.
Click Render.
Don’t worry about how it looks , we will crank up the settings later.
Assigning Textures
First, let’s texture the wall. The images used can be downloaded here:
Similarly, texture the floor.
Heres how it will look now rendered.
Now, lets texture the tires. We will put a photo texture of a tire sidewall on the side of the 3D tire. Basically what are we gonna do is select all the faces on the tire sidewall and apply the texture and just apply a dark grey shader to the rest of the texture.
Go into Face Selection mode and select all the polygons on the outer opposute side of the tire.
Before applying the planar texture map ontp the selected faces, go into the Planar UV Map Options dialog box and make sure that the correct axis is selected and also “keep image width/height ratio” is checked.
The UV Editor should look like this :
Now, in the UV Editor, goto the Polygon Menu and click on UV snapshot. [This will create a snapshot of the UV's and will help us in texturing in Photoshop] In the UV snapshot dialog box, set the directory where you want to save the image and change the image size to 1024×1024 and the file type to TIFF.
I clicked a picture of my car’s tire and used that for the texture (supplied with this tutorial) but you can find hi-res enough sidewall textures even on the internet.
In photoshop, make sure you cover the entire wireframe of the texture map with the photo texture.
Now select the rest of the faces on the tire and apply the texture tire.tiff
Heres how the tire should look by the end:
Other shaders used for the car.
Car Paint Shader
Plastic
Glass
Metallic Rim
After you have textured the plastics, metals and the glass on the car, render it again and see how it looks.
Higher Quality Render Settings
After the HQ render, you can take the render to Photoshop and apply some sharpness filters and do some color corrections.
Here’s the final result I managed to get. I changed the camera position a bit more to make it look like a print ad with some negative space towards the top left corner to place the manufacturers logo / name.
