HDRI and ground

stlkr82

Greetings.

I need advices how to properly set up ground when I use HDRI just like Bob Callawah and Cake One get in their products.
When I select any dome mode with ground, hdri looks crooked (see attachment).
is there any detailed tutorial?
 

fastbike1

One doesn't normally need to do anything with an HDRI, other than making sure Draw Ground is checked. 

I've never seen your issue, so not sure what to say.

Have you check finite sphere mode for environment, or tried to scale the HDRI?

algovincian

stlkr82 said:

Greetings.

I need advices how to properly set up ground when I use HDRI just like Bob Callawah and Cake One get in their products.
When I select any dome mode with ground, hdri looks crooked (see attachment).
is there any detailed tutorial?
 

In general, try keeping your camera position at (0, camHeight, 0), where camHeight is the the height of the camera when the panorama was made. It should be noted that while using the ground option (with either an infinite or finite sphere) will allow you to use DOF, it will also cause more severe deformations if your camera is not positioned as previously mentioned.

Hope this helps.

- Greg

fastbike1

@algovincian "In general, try keeping your camera position at (0, camHeight, 0), where camHeight is the the height of the camera when the panorama was made"

How does one know where the camera was positioned during HDRI creation?

fastbike1

@algovincian "In general, try keeping your camera position at (0, camHeight, 0), where camHeight is the the height of the camera when the panorama was made"

How does one know where the camera was positioned during HDRI creation? FWIW, I don't see this typ of distortion when I use a HDRI.

algovincian

fastbike1 said:

@algovincian "In general, try keeping your camera position at (0, camHeight, 0), where camHeight is the the height of the camera when the panorama was made"

How does one know where the camera was positioned during HDRI creation? FWIW, I don't see this typ of distortion when I use a HDRI.

You may not always know, but you can tell by the distortions. It's often easier to see the distortions with an indoor HDRI when it's not correct. Consider the 3 following 3 images:

camera at 0, 90, 0:

camera at 0, 190, 0:

camera at 100, 90, 0:

The first one looks correct. In the second one the door looks stretched because the camera height in the scene did not match the camera height when the pano was taken. In the 3rd, there are additional distortions because of the x translation of the camera in the scene.

Notes: These were all with the Ground Position Mode set to Auto (with it set to manual, you could compensate for the translations). Setting the Ground Texture Scale to 50% will have roughly the same effect as doubling the camera's height in the scene. Also, if using a Finite Sphere w/Ground, the Dome Scale will play a role.

- Greg