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Backplate issue SOLVED

PostPosted: Tue Jun 18, 2019 6:37 am
by quadcat
octane 2018.1.3.0
houdini 17.5.173
The Backplate checkbox doesn't works as expexted.
When it is ON - input texture is appear but environment geometry represents as sphere, not as flat image.
May be I doing somthig wrong but it is seems as bug.
Also I tryed modify subnet of rendertarget - no success.
Could you check attached scene?

upd. so it seems like everything work correct. But placing flat texture on background reaching by diffirent way. How?

upd.2 SOLVED

1. from here viewtopic.php?f=21&t=65575
2. create *.txt with
Code: Select all
shader CameraMap_env(
    output point uvw = 0)
{
    vector p = transform("camera", I);
    float fov;
    int res[2];
    getattribute("camera:fov", fov);
    getattribute("camera:resolution", res);
    uvw[0] = 0.5 + 0.5 * p[0] / p[2] / tan(fov / 2) ;
    uvw[1] = 0.5 - 0.5 * p[1] / p[2] / tan(fov / 2) * res[0] / res[1];

3. Go to octane render target (right click > allow edit content) and create PROJECTION OSL node
4. Load *.txt
5. Feed all interested Texture Imager nodes trough projection port - in Camera_Environment group for example

Re: Backplate issue SOLVED

PostPosted: Tue Jun 18, 2019 4:05 pm
by juanjgon
Great! Yes, this is a nice example of how a simple OSL projection shader can help with this task. Thanks for sharing your solution.

Thanks,
-Juanjo

Re: Backplate issue SOLVED

PostPosted: Thu Feb 13, 2020 3:37 am
by asamaniego
Hello,

I'm putting in the .txt in the projection OSL and when I go to compile and build GUI I get a syntax error. When I pasted the code in and connect to the projection part of my texture, it's still spherical. Please help, I just need a simple backplate for a scene. Thanks.

Re: Backplate issue SOLVED

PostPosted: Thu Feb 13, 2020 1:23 pm
by juanjgon
I think that the OSL code had a closing brace missing at the end. Try this code:

Code: Select all
shader CameraMap_env(
    output point uvw = 0)
{
    vector p = transform("camera", I);
    float fov;
    int res[2];
    getattribute("camera:fov", fov);
    getattribute("camera:resolution", res);
    uvw[0] = 0.5 + 0.5 * p[0] / p[2] / tan(fov / 2) ;
    uvw[1] = 0.5 - 0.5 * p[1] / p[2] / tan(fov / 2) * res[0] / res[1];
}



Thanks,
-Juanjo

Re: Backplate issue SOLVED

PostPosted: Thu Feb 13, 2020 4:09 pm
by asamaniego
Yes! Works...thank you!!!

Re: Backplate issue SOLVED

PostPosted: Mon Feb 22, 2021 8:47 pm
by muchogrande
Could someone explain this a little further? I created the Projection_OSL node in the rendertarget and added the code, but I'm a little lost what I do next to apply an image?

Re: Backplate issue SOLVED

PostPosted: Tue Dec 21, 2021 11:27 pm
by Renbry
@muchogrande - here's a snipping showing how the Projection OSL gets plugged into the existing node network. Specifically the PROJECTION plug on the CamEnviroTexture.

Then you'd just need to make sure your Render Target has Cam Environment turned on in the MAIN tab to make visible the file name selector to choose your background image

Capture.PNG

Capture2.PNG

Re: Backplate issue SOLVED

PostPosted: Tue Dec 21, 2021 11:29 pm
by muchogrande
Awesome, thank you!