Cycles Vehicle composite with HDR and backplate Help

Hi Guys!

Compositing cars with HDRI and backplates has been all the rage with other software for a while now - but there’s no info on doing this with blender and Cycles.

I’ve just downloaded a free lovely snowy HDRI with several backplates from http://hdri4free.com

There was a 3DS tutorial at:

I’ve been at blender for several years now, and was wondering if there was anyone here knowledgable enough to know a similar procedure with blender and Cycles.

I’m no node king, but I know my way around, and have no problem adding a HDRI to light to the scene for lighting/reflections, or any problem adding a backplate to the camera view etc. I was hoping to get some help with the node set up for the render layers - I’m using 2.62 currently. Anyone got a good working method please?

Here’s an example of my work currently:


It would look so much better with a real background naturally :wink:

If I can get a good idea of this then I’ll post up the info for everyone to share and stick something on blendswap too - I’m sure others would love to have a crack at it too!

Jay :wink:

Hi, if i understang you , you are looking for environment lightning with hdri maps.
It is very easy, here is a tutorial.

http://blendernerd.com/environmenthdr-lighting-in-cycles/

You need a latlong image, cheers, mib.

No mib2belrin, there’s a bit more to it than that, nerds tut is just adding a HDR image to a scene to light it - childs play pretty much.

What’s required with what I talking about is:
Light the Scene with HDRI
Use reflections from HDRI
Render passes/layers so you can composite them onto a background and a plane for the shadows, the plane invisible except the shadow pass.

The free HDR images I was talking about come with 1xHDRI and several backplates (backplates are png/jpg images taken from the HDR image and show different angles of the location) to use as backgrounds in the viewport. Which of course will be added in the node set up with an alpha-over to bring them all together.

I guess the 3ds max tutorial kinda demonstrates the technique. :wink:

I feared it is more complicated.
First problem, cycles has no shadow pass. Quick and dirty scene with a bmw from Mike Pan:
Background plane with jpg, light and reflection from HRDI, area light with image texture.
Hm, you could copy the scene and render the shadow pass with blender internal renderer.
But i am not so a skilled user especially with composite nodes, may others can help better here.

http://www.pasteall.org/blend/11948

Cheers, mib.

Attachments


This is what I managed to get after pre-rendering a AO pass with BI. I simply composited it on top of the ground plane (which was in its separate render layer) using the Color output. Lastly the car was added on top. It’s a crappy solution really, but without an AO/shadow pass in Cycles there’s not much else to do.


I suggest you take a look at the .blend as it’s easier than explaining everything in detail. Everything should be included in the file, even the HDRI. :slight_smile:

http://www.pasteall.org/blend/11949

Cheers Daccy, I’ll check it out. Roll on a shadow/AO pass! - wonder when that’ll be? That’s odd, I recognise that car from somewhere :wink:

Hi Daccy, Thanks again for your blend, I think I understand what’s involved with the ‘dirt’ aproach to using the shadow/ao pass in BI, then using that to render with cycles.

Even though you packed the files, for some reason they aren’t showing up - i.e. if I render your scene, all I get is a blank screen. If I try to export the textures I get an error.

Anyway I thought I’d have a crack at creating the shadow/ao pass myself as I tried before, one issue still arises though, being fool with nodes I still can’t extract the shadow/ao pass correctly, the plane is still visible!

Could you advise me to do it correctly please if it’s no bother? Also on that is it advisable to combine the AO and shadow pass? some of my backplates have the sun quite low, so it seems that it would be important to include both.

Then I’ll follow your node setup to see where I get.

Cheers, Jay. :wink:

Ok, here’s a picture describing how the node setup works. Hopefully it’s somewhat comprehensible. :slight_smile:


Also, here’s the .blend with the textures and HDRI unpacked into a folder, so it should work now:
http://www.sendspace.com/file/f56qbe

Remember that in order to render the AO/shadow passes, you need to enable them for the corresponding render layer and then either connect a ‘File Output’ node to them, or simply a ‘View’ node, where you just have to save the passes manually.

Regarding the shadow pass, you need to convert all (or most) of your shaders to BI materials first, because BI doesn’t recognize Cycle’s shaders. For this it’s just easier to duplicate the .blend so you don’t have to change the materials back and forth.

Thanks for the help, very generious of you. I’ll check out your new file and the node grab discription tonight - some homework for me! :slight_smile:

Thank you Daccy. Hopefully there will be a Cycles shadow catcher some time.

Just to confirm, Daccy’s technique worked a treat, I’ll upload a render later today to demonstrate. :slight_smile:

Cool! :slight_smile:

And yes, more passes would make it so much easier.

Jay-artist I didn’t post therender you were talking about ?
It would help me to understand thank you

Daccy your file link is dead (http://www.sendspace.com/file/f56qbe) , any way to get it again
Thank you