HDRI textures?

HDRI textures?

Hello everyone,

is there a website where I can get HDRI files for free ?
Or is there a freeware tool which can generate HDRI files ?
 
I haven't worked out how to control the size/ orientation of HDR backgrounds in cheetah.
For instance: if I have, say, a model of a piece of furniture and I want it to sit in "the middle" of an hdri room, how would I set whereabouts, what "scale", and in which direction the background HDRI is?

Anyone help?
N.
 
propstuff said:
I haven't worked out how to control the size/ orientation of HDR backgrounds in cheetah.
For instance: if I have, say, a model of a piece of furniture and I want it to sit in "the middle" of an hdri room, how would I set whereabouts, what "scale", and in which direction the background HDRI is?

Anyone help?
N.

You really can't control the size or position. It is what it is. But what I have found the lighting changes quite a bit depending on which way the model faces. That's the nature of HDRI probes. So, what I do is put the entire model and lights in one folder, click on the folder, and turn everything till the lighting and background meets my needs. You will have to move your camera. I don't think you can link a camera to a viewpoint and make it stay as you rotate. At least I haven't been able to yet.

Martin is this possible?

ps. Speaking of cameras. I always use one camera for my render view and another is set up above the model to move lights and objects around.
 
Jake said:
You really can't control the size or position. It is what it is.

That's a bummer.

In my tests I've ended up with objects "jammed up" against the walls which looks not real at all: the perspective and depth of field are bungo.
Specially as the backgrounds are comparatively fuzzy.

Oh well....
 
propstuff said:
Jake said:
You really can't control the size or position. It is what it is.

That's a bummer.

In my tests I've ended up with objects "jammed up" against the walls which looks not real at all: the perspective and depth of field are bungo.
Specially as the backgrounds are comparatively fuzzy.

Oh well....

Zip the file along with the hri and send it to me.
 
Jake said:
You really can't control the size or position. It is what it is. But what I have found the lighting changes quite a bit depending on which way the model faces. That's the nature of HDRI probes. So, what I do is put the entire model and lights in one folder, click on the folder, and turn everything till the lighting and background meets my needs. You will have to move your camera. I don't think you can link a camera to a viewpoint and make it stay as you rotate. At least I haven't been able to yet.

Martin is this possible?

I am doing the same thing. I did discuss this with Martin sometime ago and proposed to include an option to be able to rotate the HRDI background. So, he is aware of it and this is on the to-do list
 
Hi again Jake,

Here is an example of the problem I was referring to above.
I was trying to get the box (think piece of furniture) to sit "on the floor" in this test HDRI I made with Photosphere.


The room was photographed at eye height (1500mm) with the camera level and looking straight ahead.

You can see that my stylish piece of furniture is sort of floating in space with no spatial relationship to the background. I tried manipulating the box's Position in Ch but it didn't make any difference as far as matching perspective etc.

is this something that's achievable, or should I forget trying to do that and just present my design in a room I've constructed and let the HDRI provide just the lighting?

cheers,
N
Cheet2.jpg
 
propstuff said:
Hi again Jake,

Here is an example of the problem I was referring to above.
I was trying to get the box (think piece of furniture) to sit "on the floor" in this test HDRI I made with Photosphere.


The room was photographed at eye height (1500mm) with the camera level and looking straight ahead.

You can see that my stylish piece of furniture is sort of floating in space with no spatial relationship to the background. I tried manipulating the box's Position in Ch but it didn't make any difference as far as matching perspective etc.

is this something that's achievable, or should I forget trying to do that and just present my design in a room I've constructed and let the HDRI provide just the lighting?

cheers,
N
Cheet2.jpg

propstuff,

First, I think your camera light is on-turn it off. Go to the camera settings and scroll down. You'll see the checkbox. You'll get a much more realistic lighting.

The hdri question is one I asked on another thread. This is what I proposed:


Thomas,

You need to post that same model with it levitating off the surface as if it was hovering.

Better yet, get rid of plane below it and make it look like its floating in the square you used for an HDRI.

Which makes me think. Is there a way to put a plane below the object so it will receive a shadow but does not appear on camera? That way it will look like the object is casting a shadow in the the ground of the HDRI. Perhaps a transparent surface of some sort.

Sound dumb?


No one replied.

I have not tried to do it. I think you will need an hdri made from a low level to to it properly and I don't know if it can be done.

Rumor is that the new Photoshop will allow you to make HDRIs. I have a fisheye for my old nikon 990 so I can give it a try in a couple weeks.

I think the best solution is creating you own environment. Sorry I couldn't answer that better. I'll bet Martin has a better answer.
 
Hi Jake,
sorry that I missed that.
To cast a shadow onto a HDRI background you need some geometry as you already said. A renderer can't know by itself on what a shadow should be cast and a HDRI doesn't include any depth information.
But you also need a special shader for the background geometry which Cheetah3D doesn't offer yet. The shader/material must be transparent if it is in the light and black if it is in the shadow. Such a shader is already on my todo list.

Here is a tutorial for compositing a object into a scene with another 3D app:
http://www.dbki.org/tutorials/eng/compositing/composit.htm
It should at least give you some ideas how it could work. But in general it is quite tricky process to make it look really realistic.


By,
Martin
 
Really not a problem Martin. I thought someone else may have run into this problem before and had a good solution.
 
Francois said:
I am doing the same thing. I did discuss this with Martin sometime ago and proposed to include an option to be able to rotate the HRDI background. So, he is aware of it and this is on the to-do list.

The next update (v2.2 or v2.2b4) will offer this option to rotate HDRI backgrounds. Check out the "Rotate background" property in the HDRI tag.

By,
Martin
 
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