Image Based Lighting Test

[RS3D]

I made a test with image based lighting to see if it helps in integrating Hash models with background photographs. I am happy with the color mixing, but I think the shadows could be better. I added some color distortion in the middle of the image to give it the reflection artifact you tend to see on sun lit pictures. I tried the z-buffer shadow option, but the results were kind of weird. For example, it did not show a projected shadow from the barrel in the scene. I would appreciate it if someone could take a minute to look it over and let me know if you think it looks realistic or needs further work.

[robcat2075]

There's a thread or a tut around here by Jason1025 where he talks through doing this image based lighting stuff.

 

For example, it did not show a projected shadow from the barrel in the scene.

 

A ground plane will need to be set to Cast Shadows ON in its options for a single patch to properly cast a shadow on it. That might be the problem.

 

 

I am happy with the color mixing, but I think the shadows could be better.

 

The razor sharp shadow probably don't look right. You can try the z-buffered lights again. Or, ray-traced lights have a "width" and when you use that with multi-pass they will jitter to create authentic fuzzy shadows that get fuzzier as they get farther from the object.

 

To me it doesn't look like there's any AO happening. We should see some darkening around the base of things or under the helicopter. Perhaps some crucial setting is not right on that.

[John Bigboote]

Yeah, I'm not seeing the AO... is it 100% IBL or do you have some lights in there as well?

[Fuchur]

Yeah, I'm not seeing the AO... is it 100% IBL or do you have some lights in there as well?

 

Did you activate Ambient Occlusion in the rendersettings?

 

See you

*Fuchur*

[RS3D]

Robcat pointed out that there are problems with single patch ground planes and image based lighting. Once I changed to multi-patch

ground planes, the texturing that wouldn't render in the original post suddenly did appear. So that solved that problem.

 

Fuchur pointed out I may not have set ambient occlusion settings in the render. I did have it set in the render options but not in the

option that shows up in the image based lighting dialogue. So setting it in both places may have helped, but because of some other

shadow issues, I am not sure.

 

John Bigboote asked about the status of additional lights in the choreography. There is one klieg light which is the one that is supposed

to make the shadows. It is located above the scene and projects from left to right to match the shadows in the background image.

 

Now that I have some of the initial problems resolved, I now have some additional ones that have occurred. See the new render.

 

 

Because the objects in the choreography are so close together, I get a strange-appearing location for the helicopter shadow in the

render from the camera view. I decided to try light lists to see if I could isolate the lighting on the helicopter. I finally figured out

how they work but it seems that the klieg light still renders shadows even if a model is not included in the light list. In the

new render, only the soldier, garbage can and ground planes have light lists.

 

My question is: am I doing something wrong or is that the way it should be? Does the ground plane light (the shadows part) list override

fact that not all of the models have light lists?

[robcat2075]

Robcat pointed out that there are problems with single patch ground planes and image based lighting.

 

I as referring to a general problem... a single patch thickness surface will only cast a z-buffered shadow on the ground plane if the ground plane is set to "Cast Shadows" ON.

 

In v17 and later the ground plane has that set ON by default but it was OFF in previous versions.