[mashium123]

hi,

i have a question about the rules.
seeing the threads started so far, i realize people use the hdri not only for illu/refl purposes but also as the background.
now i'm a bit confused.

aren't we supposed to use the photos as backgrounds? at least, that's how i understood it. this would make the renders more comparable, i would have guessed. i mean, when using the spherical hdri, one could turn the map as one pleases, so the background would look different all the time.

here's what i mean by "using the photos as background":


thx.

[Mihai]

I guess the rules aren't too clear on this point, but I suppose logically yes, you should stick to the provided blackplates in order to integrate your object into the photo, and all contestants must use the provided backplate for the HDR they used.

[mashium123]

ok, thanks for the clarification.

[Ernesto]

hi,

thx.

Mashium, you are the first to show a PERFECT composition using the floor in the HDRImages by Maground. I am havng trouble to get the shadows on the ground as you did, probably because I am not understanding the right procedure.
Some users and a NL member: Dario Lanza have been helping me to understand this here: http://www.maxwellrender.com/forum/view ... 32&t=40247
I have found a tuttorial in the web, here:
http://hdri-spherical.com/tutorial-usin ... art-2.html
but it seems to be incomplete for my level.
Here you can see my last attemp:
http://www.maxwellrender.com/forum/view ... 47#p366520
Now tthanks to you I know the background image is not right. I am changing it now.
But coming back to the shadows problem:
Could you please describe the method?

Ernesto

[mashium123]

hi ernesto,

i fear, i have to dissappoint you, since this is just a quick and dirty thing (i mean, it's just a sphere, right?). i was just trying to have a look at the contributor's hdri quality and test it out a bit, since one is always looking around to find quality producers of nice things to work with, right?
so, this render is not a composite, as i would have done, if i'd tried to dive into this competition.
it's an out-of-the-box render, the beauty-pass itself.

but if you're interested in that too:
- put the backplate into the background-slot.
- put the hdri-map in all the other slots.
- match the hdri rotation-value to the background plate, so that the building matches. then you should have a quite similar surrounding.
- put the sphere into the scene so that the bottom edge of the sphere is zeroed.
- put a (quite big) plane under the sphere.
- take the backplate and make an mxm out of it.
- attach the backplate-mxm to the plane, projection: camera-mapping (or what it's called in your 3d-host app) - you may need to subdivide the plane... depends.
- now adjust the illumination, reflection, camera-settings in a manner that it fits to the background.
- done.

as i said. quick and dirty. doesn't always work very well, when done quick and dirty, since doodling around with the illu/refl-settings just to get the plane matched to the background can be tiring.
compositing is the way to go, if you're interested in serious business and want to have a vast amount of flexibility.

[Ernesto]

hi ernesto,

i fear, i have to dissappoint you, since this is just a quick and dirty thing (i mean, it's just a sphere, right?). i was just trying to have a look at the contributor's hdri quality and test it out a bit, since one is always looking around to find quality producers of nice things to work with, right?
so, this render is not a composite, as i would have done, if i'd tried to dive into this competition.
it's an out-of-the-box render, the beauty-pass itself.

but if you're interested in that too:
- put the backplate into the background-slot.
- put the hdri-map in all the other slots.
- match the hdri rotation-value to the background plate, so that the building matches. then you should have a quite similar surrounding.
- put the sphere into the scene so that the bottom edge of the sphere is zeroed.
- put a (quite big) plane under the sphere.
- take the backplate and make an mxm out of it.
- attach the backplate-mxm to the plane, projection: camera-mapping (or what it's called in your 3d-host app) - you may need to subdivide the plane... depends.
- now adjust the illumination, reflection, camera-settings in a manner that it fits to the background.
- done.

as i said. quick and dirty. doesn't always work very well, when done quick and dirty, since doodling around with the illu/refl-settings just to get the plane matched to the background can be tiring.
compositing is the way to go, if you're interested in serious business and want to have a vast amount of flexibility.

VERY CLEAR!!!!
Thanks a lot.
I ill work on this now.
E

[mashium123]

you're welcome.

but, if i may say, i would really try and get my head around compositing in combination with maxwell.
the described method is really just a quick/dirty thing.

you're way more flexible, if you go the layered way.

[Ernesto]

you're welcome.

but, if i may say, i would really try and get my head around compositing in combination with maxwell.
the described method is really just a quick/dirty thing.

you're way more flexible, if you go the layered way.

Thanks mashium for your recomendation.
As am not succeeding doing this up to now, I think thee best I can do now is trying with the "dirty" easy way to start.
Then I could goto more complex stuff.

Now my machine is Crashing. As soon as I use the provided backplate in the Background Channel, it crashes. Perhaps beacuse I cannot set spherical mapping to the Ilumination Channel, where the HDRImage is loaded...
If I do not use the backplate as Background it works OK.

Well, I give up! As soon as i place the backplate in the background tab, maxell crashes or it renders a black image. I have tried reducing the size of the image, I have tried changing the format but nothiong seems to work! I m using Maya 2012 and Maxwell 2.7 (newest version)
Is anybody having the same problem?


Ernesto

[mashium123]

...
Now my machine is Crashing. As soon as I use the provided backplate in the Background Channel, it crashes. ...

usually, the maxwell environment-slots generally will only accept 32bit-maps.
so, you will have to convert the backplate tif to an exr-file for example (sorry, i never mentioned that one).
for example the maxwell render app does that for you. start the app, load the image and save as exr or hdr.

i don't know what your host app is.
in cinema4d (that's what i made it in) it does not crash, when a non 32-bit is applied. i just doesn't work.
in maxwell studio one even does not have the option to load any other format than 32-bit one.

[Ernesto]

Thanks Mashium,

This was a really tricky limitation!
This is one of the things that would deserve a written warning in the competition rules.

I did converted the image to mxi format, because the Maxwell Render software, cannot save other format. There is a comand called SAVE MXI AS but the only option was mxi again!
It worked now! thanks again!

I can see that the image is exposure sensitive, but you cannot use the exposure that you want because only one value works ok. All the other values makes the image look bad.
I makes little sense to start with a wonderfull spherical HDR to convert it into a 8 bits image, and then to reconvert to fake a 32 bits again....
I do not see the point!
The logical thing would have been to convert or crop the plate directly from the original panoramic image, keeping the 32 bits information intact, which would let the user to adjust the exposure keeping the original accuracy, therefore realism.

Ernesto

[Ernesto]

One more thing Mashium!

In order to create the material for the ground plane, should I use the 32bits map, or the 8 bits version?

Ernesto

[mashium123]

Thanks Mashium,

This was a really tricky limitation!
This is one of the things that would deserve a written warning in the competition rules.

i would believe, that quick&dirty methods like this are not meant to be used for production purposes in the first place.

I did converted the image to mxi format, because the Maxwell Render software, cannot save other format. There is a comand called SAVE MXI AS but the only option was mxi again!
It worked now! thanks again!

it does work for sure:
maxwell render app->menu:"file"->"load image"->(choose the .tif backplate)->menu:"file"->"save image"->(save as .hdr or .exr)

I can see that the image is exposure sensitive, but you cannot use the exposure that you want because only one value works ok. All the other values makes the image look bad.
I makes little sense to start with a wonderfull spherical HDR to convert it into a 8 bits image, and then to reconvert to fake a 32 bits again....
I do not see the point!
The logical thing would have been to convert or crop the plate directly from the original panoramic image, keeping the 32 bits information intact, which would let the user to adjust the exposure keeping the original accuracy, therefore realism.

Ernesto

i'm not sure, i get this one.
are you trying to convert the hdri? the only thing in this q&d-method that is to be converted at all is the backplate, since this is in 8bit-tif, not the hdri. and the conversion is only for the purpose of putting it into the background-slot.

[mashium123]

One more thing Mashium!

In order to create the material for the ground plane, should I use the 32bits map, or the 8 bits version?

Ernesto

i used the delievered tif backplate, straight forward, just like it was.

[Ernesto]

well, Mashium,

I am going very slowly, but in the right direction hopefully since your intervention!
thanks again!

This is what I have got.



The background image now is a mxi, and the intensity had to be multiplied by 50 to make it visible. Otherwise it was dark gray.
The ground plane has a material created with the back plate using the original hdrimage.
Now the 3d model is projecting real shadows on the ground.
The UV for the ground plane was set to camera projection.


But something is obviously wrong with it.
I am having problems setting the projection (working in maya 2012)

Any hint?

Ernesto

[Mihai]

The point of loading the background plate (the .tif, the regular photo, NOT the HDR) in the IBL background slot is simply for this step:

- match the hdri rotation-value to the background plate, so that the building matches. then you should have a quite similar surrounding.

so simply to line up the HDR sphere lighting with where the photo was taken (by rotating the HDR image used in the other IBL slots (illum, refl. refr)). So that when you render, you're not using the "wrong" side of HDR and the reflections/lighting in your object look wrong.

After you've done this step, you can uncheck the background slot, you don't need it anymore, and either render with alpha channel and shadow channel and composite later (as described here http://support.nextlimit.com/display/ma ... ow+channel), or, keep the background slot visible and:

- attach the backplate-mxm to the plane, projection: camera-mapping (or what it's called in your 3d-host app)

and do it all in one render. Quicker but less flexibility.