Corona Renderer Forum

Corona Renderer for Cinema 4D => I need help Cinema 4D => Topic started by: iacdxb on 2019-03-06, 08:31:40

Title: HDR image as area light
Post by: iacdxb on 2019-03-06, 08:31:40
Best way to use a hdr light image as area light....?

No texture slot in Corona Area light. Placed HDR in Self Illumination... it needs more multiplier power to illuminate target area and IR is more noisy and passes 300+ to clean render on other side a simple area light needs do this in 15 or 20 passes for clean render.

How you use HDRI as area light...?

Thanks.
...
Title: Re: HDR image as area light
Post by: SairesArt on 2019-03-06, 10:31:00
Placed HDR in Self Illumination...
Don't do that, the noise will clear up very slowly.  There is a whole article on the corona help desk (https://coronarenderer.freshdesk.com/support/solutions/articles/5000515603), when to use Self-illum and when to use a light.

I don't know where in C4D, but CoronaLight has a TexMap slot. This allows you to input an HDR map. The shape of the Light does not matter. The standard rectangle "area" light works here just as well. Also the CoronaLight material does the same and has a texmap slot as well.
If by chance you require the image to be a perfect projection (think office projector), then the CoronaLight's texmap slot won't work properly.
There is a whole thread on how to do video projection in C4D. (https://corona-renderer.com/forum/index.php?topic=23464.0).

But to just get the light color, shape, softness, strength from the HDR image, then the Corona TexMap slot is the right tool.
Title: Re: HDR image as area light
Post by: iacdxb on 2019-03-06, 11:05:45
Placed HDR in Self Illumination...
CoronaLight has a TexMap slot. This allows you to input an HDR map.

Can you please drop a screen shot of TexMap slot...?

That I know the link of light usage but I need a special HDRI reflection over the object.... for that I was trying as a key light.

Thanks.
...
 
Title: Re: HDR image as area light
Post by: mb3d on 2019-03-06, 11:33:22
Use the Corona light material. Then put the light material on a plane next to the object your trying to light.
Title: Re: HDR image as area light
Post by: iacdxb on 2019-03-06, 12:25:57
Yes... this "Light Material", I tried this also.

Again back to my first post..... it need 300+ pass to noise clear render and Corona Area light needs 20 passes.....!

Does anyone tested....?

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Title: Re: HDR image as area light
Post by: beanzvision on 2019-03-06, 15:53:38
Yes... this "Light Material", I tried this also.

Again back to my first post..... it need 300+ pass to noise clear render and Corona Area light needs 20 passes.....!

Does anyone tested....?

...

Well, on my test with an HDRI applied to the Corona light material (assigned to a plane) I stopped the render at 7 passes. So I'm not sure why yours need >300 or more passes. Where is the HDRI from? What is it? Even better, maybe a test scene would help ;)

(https://corona-renderer.com/forum/index.php?action=dlattach;topic=23936.0;attach=100004;image)

(https://corona-renderer.com/forum/index.php?action=dlattach;topic=23936.0;attach=100006;image)
Title: Re: HDR image as area light
Post by: iacdxb on 2019-03-07, 03:55:09
Right Bean... this HDRI is not proper. It was given for special use in a project....!

I tried other HDRI... its like Cheetah....!

Thanks.
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Title: Re: HDR image as area light
Post by: beanzvision on 2019-03-07, 12:32:34
Right Bean... this HDRI is not proper. It was given for special use in a project....!

I tried other HDRI... its like Cheetah....!

Thanks.
...

I don't understand what you're asking here.....

HDRI is not proper. ????

Its like Cheetah???

What the..
Title: Re: HDR image as area light
Post by: burnin on 2019-03-07, 13:12:15
Dear iacdxb,
Remember?

1. Show what you've done (images, scene files...). 
2. Explain, describe in simple words, step-by-step process that got you into the mess you're stuck with. If it's HDRI, show it, share it for diagnosis, analysis sake.

What you got here is basic, simplest & most effective way to lit the scene with non-spherical (non-equirectangular) HDRIs. Basically HDRI texture on a plane.

But, there's also a concept so called Karma, meaning: "Shit in, shit out." Bad HDRIs are nothing uncommon. Especially custom made, coming from  ppl knowing nothing but shit. ;)


Title: Re: HDR image as area light
Post by: iacdxb on 2019-03-07, 21:49:37
Right Bean... this HDRI is not proper. It was given for special use in a project....!

I tried other HDRI... its like Cheetah....!

Thanks.
...

I don't understand what you're asking here.....

HDRI is not proper. ????

Its like Cheetah???

What the..

I think it was simple...

That HDRI was not correct.... I tried other HDRI and works fine as you shown.
And Corona works like Cheetah (speedy), as it should....!

...
Title: Re: HDR image as area light
Post by: iacdxb on 2019-03-07, 22:31:51
Dear iacdxb,
Remember?

1. Show what you've done (images, scene files...). 
2. Explain, describe in simple words, step-by-step process that got you into the mess you're stuck with. If it's HDRI, show it, share it for diagnosis, analysis sake.

What you got here is basic, simplest & most effective way to lit the scene with non-spherical (non-equirectangular) HDRIs. Basically HDRI texture on a plane.

But, there's also a concept so called Karma, meaning: "Shit in, shit out." Bad HDRIs are nothing uncommon. Especially custom made, coming from  ppl knowing nothing but shit. ;)

Hi Burnin, you....? May be I forgot, my short term memory....!

I wish to show but can not.... it was for client side and update him...!

Many HDRI now a days on net and everyone is doing... wasted lots of money on that and now checking first or recommended by some other pro and then, no direct buy.

Thanks.
...
Title: Re: HDR image as area light
Post by: burnin on 2019-03-08, 11:55:40
Well, at least that's sorted...
Have a nice day and a pleasant weekend.