HDRI shadows

[Kaare Baekgaard]

Here comes the first wish based on 12.5:

HDRI works great for outdoor scenes and product design. For indoors it is quite promising, but not quite there yet:

I get strange shadows all over the scene. I can cure it somewhat by setting textures to not cast or recieve shadows, but it will be quite a puzzle and probably not worth the efford when you are on the clock. Too bad really, because without the shadows, the overall effect is quite nice.

So I wish there were some way to turn off shadowcasting for HCRI maps.

[propstuff]

Hi Kaare,

I've been hoping for HDRI for some time now, so I'm happy. :-)

Thankyou Dave and NNA.

Unfortunately I have to wait a little to get it.

You said you're using it for Interiors. Can you tell me; where is the HDRI placed in respect to the walls of your interior?

regards,

N.

[Kaare Baekgaard]

Hi Nicolas

I don't think I have an option to place the HDRI map as it is set to surround the entire workspace. The shadows seem to come from several sources - and are not of equal strength, but they still have sharp edges in final quality renderworks. I suppose they are calculated to emanate from multible sources based on light areas of the HDRI map.

I have made a routine for interiors, where the ceiling and all objects placed above the furniture cast no shadows - sometimes I also set some of the walls to cast no shadows. That way I can use global directional lights to create shadow footprint(s) of all interior furniture.

I just loaded a HDRI map into such a scene and deleted the directional lights, then started the renderer.

The resulting image displayed toned surfaces correctly according to the HDRI map. These tones had 'burned' through walls and floors so seemingly most of the map does not produce shadows. (Just like when you set a global coloured light to cast no shadow - the colour burns through objects, that would block the colour, if the light were set to cast shadow).

But I got strange shadows on the walls and ceiling, that I have not yet understood - perhaps from windows, I don't know. When I learn more, I will give you an update.

[propstuff]

I don't think I have an option to place the HDRI map as it is set to surround the entire workspace.

That's been my experience of them. that's why I was wondering how you lit an interior with them.

The shadows seem to come from several sources - and are not of equal strength, but they still have sharp edges in final quality renderworks. I suppose they are calculated to emanate from multible sources based on light areas of the HDRI map.

My understanding was that they behave sort of like area lights except graduated (by the brightness of the image). I'm not sure why they would cast sharp shadows like you describe.

I just loaded a HDRI map into such a scene and deleted the directional lights, then started the renderer.

The resulting image displayed toned surfaces correctly according to the HDRI map. These tones had 'burned' through walls and floors so seemingly most of the map does not produce shadows. (Just like when you set a global coloured light to cast no shadow - the colour burns through objects, that would block the colour, if the light were set to cast shadow).

Curious. I'm not sure I can picture the result. ;-)

But I got strange shadows on the walls and ceiling, that I have not yet understood - perhaps from windows, I don't know. When I learn more, I will give you an update.

please do. (and post an image if you can)

One last question: was the result good?

cheers,

N.

[Kaare Baekgaard]

Hi again

Well I should learn to investigate a little before I make a statement. Please disregard everything I have written so far. I was cheated by the ceiling and a single wall set to not cast any shadows. Just did a rendering of the interior of an entirely closed building - and nothing 'burned' through. - Oops

The bit about the sharp shadows is somewhat correct, however. It seems there is an array of directional lights, a limited amount, each of which cast a sharp, graduated shadow onto the scene. Is that true HDRI?

As to the last question: Well - it was interesting, but I feel a little violated afterwards...

Yesterday evening I did a rendering of a wall lamp, where I used the HDRI map only as an environment/reflection map - and I used traditional lighting of the scene. You can do that through the set layer lighting option menu item.

The result was breathtakingly nice - rendered fast and was so easy to control. Sorry I cannot show the result, as it is a product in development

[Kaare Baekgaard]

Well now I feel really stupid - and perhaps I am...

The limited amount of shadows come from a HDRI map, I had set tol 'low' quality. The same scene rendered with higher quality setting produces no discernible sharp edges. The may be there, but I cannot distingush them. The rendering time, however is slow.

[propstuff]

Well now I feel really stupid - and perhaps I am...

Ha! you wouldn't believe the stupid things I've done over the years. :-D

The limited amount of shadows come from a HDRI map, I had set tol 'low' quality. The same scene rendered with higher quality setting produces no discernible sharp edges.The may be there, but I cannot distingush them.

That's what I would have expected. Good to hear :-)

The rendering time, however is slow.

The rendering I've done with HDRI has taken time, but the results (for product) are well worth the time -and far less effort to set up than other lighting types.

cheers,

N.