Backplate issue SOLVED Tweet

[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

[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

[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.

[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

[asamaniego]

Yes! Works...thank you!!!

[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?

[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

[muchogrande]

Awesome, thank you!