Hi

I have all my scene ready to render in Houdini 9.5

I am using an image for my background and I have a portion of a building falling a part.

I am using camera projection for my building with a basic material and a UVTexture node.

My problem :

Everything looks great , but when I send my render to Mantra, the default light appears on the box creating shadows. ( The light is not matching the scene ).

I went to my render properties and I deactivate the default light. ( Now everything goes black ).

PLEASE “I need my 3D objects to match the scene”

I have been using Cinema for a long time and there you have tags for compositing. But here in Houdini I don't know if those settings are in the render node or in lights or anywhere else.

I don't know what to do, is driving me crazy, to much time in the help menu and still I don't get it.

If anybody knows how to do this I will be eternally grateful

You need to use a constant shader - one the uses the raw texture color and ignores the lighting.

You can do this with the “VEX Super Material” shader. Turn Diffuse to 0,0,0 and Emission to 1,1,1. Put your texture map (your camera plate) in the emitmap field.

That'll do it.

Good luck,
Jason

jason_iversen
You need to use a constant shader - one the uses the raw texture color and ignores the lighting.

You can do this with the “VEX Super Material” shader. Turn Diffuse to 0,0,0 and Emission to 1,1,1. Put your texture map (your camera plate) in the emitmap field.

That'll do it.

Good luck,
Jason

You should also be able to use the “Constant” material from the material palette (and set the color map from there).

That was great

Thank you

Sorry but now I am having trouble when I try to render shadows, I can see my 3d objects but I do not see the shadows.

I am using the constant and the super material , but both of them are doing same thing.

I have a simple image and I want to place a sphere on the floor and have the shadow of the sphere reflected on the floor. I am using one grid as my floor with a camera projection and constant material with the image.

Everything looks fine but not shadows. The constant shader is not accepting lights true?

But how can accept just the shadows to have a more realistic look?

Should I use takes ?

yes, you would probably want to do a separate take for this.

in one take, you would have your constant material environment which would be reflected in or cast shadows onto your 3d elements. You would likely have your environment render as phantom (an option on your objects).

in a second take, you would want your environment to have a shadow matte material applied, and tell your 3d elements to render as phantoms. This will give you a shadow pass that you can easily tweak in comp (a black color, with an alpha channel wherever your shadows are).

to speed up integrating 3d elements into a real world footage, a useBackground like material would be nice, which would pick up the background pixels, but could render shadows and reflections visible, just to make the lighting process easier, of course after it would be rendered in a separate pass