Camera Projection

[Scaletta]

Hello everyone. Well am very much new to houdini and I'm working on camera projection, but there is an error as seen in the screenshot. How do you think I can remove the lines on the edges and make the color match?

 

Edited May 10, 2022 by Scaletta

[doc]

It looks like your geometry is picking up lighting, which it doesn't need because the lighting already exists in the image. Try rendering the geo with a constant shader. The issue should go away 

[Scaletta]

9 hours ago, doc said:

It looks like your geometry is picking up lighting, which it doesn't need because the lighting already exists in the image. Try rendering the geo with a constant shader. The issue should go away 

Thank you it was nice with constant shader but this time the depth of the shards disappeared. I think I'm making a mistake somewhere.

 

[evanrudefx]

7 hours ago, Scaletta said:

Thank you it was nice with constant shader but this time the depth of the shards disappeared. I think I'm making a mistake somewhere.

 

Are you using a separate material for the inner faces? That might help. I think you just don't want lighting on the top faces where your texure is being projected. The rest of the geometry needs lighting otherwise it looks flat. You just don't want lighting on the top faces so that it matches the footage. The fracture node outputs inner faces groups to help with that.

[doc]

ejr32123 is correct. You want a constant shader on the top of the sidewalk, but you want proper lighting on the fractured interior faces. 

A larger issue you'll have is when the pieces break and move the lighting on the top surface should change. The shadows should change, the diffuse and specular lighting should change. But how do account for this if the lighting is baked into the projected image? No easy answer as far as I know. People often make a copy of the original image and try and remove specular and shadows in the hopes of creating a diffuse texture map that can be used with a principled shader. Photoshop or gimp seem the most obvious tools to do this, but I believe that there are some photogrammetry solutions that have some automated mechanisms for doing this.

Once this is done you'll need to reproduce the lighting in cg so that it matches the photo. You'll probably need to render a shadow pass for areas where your cg debris is supposed to cast shadows on the constant surface. Then it'll probably take some love in compositing to make it all work.

Hope that helps

[evanrudefx]

14 hours ago, doc said:

ejr32123 is correct. You want a constant shader on the top of the sidewalk, but you want proper lighting on the fractured interior faces. 

A larger issue you'll have is when the pieces break and move the lighting on the top surface should change. The shadows should change, the diffuse and specular lighting should change. But how do account for this if the lighting is baked into the projected image? No easy answer as far as I know. People often make a copy of the original image and try and remove specular and shadows in the hopes of creating a diffuse texture map that can be used with a principled shader. Photoshop or gimp seem the most obvious tools to do this, but I believe that there are some photogrammetry solutions that have some automated mechanisms for doing this.

Once this is done you'll need to reproduce the lighting in cg so that it matches the photo. You'll probably need to render a shadow pass for areas where your cg debris is supposed to cast shadows on the constant surface. Then it'll probably take some love in compositing to make it all work.

Hope that helps

Not sure how to do it in mantra, but in redshift I can make a material that receives GI and shadows (and I can also disable one or both of those if I want),  but not normal lighting. That way my texture matches the scene but can also pick up shadows in case a shadow is cast over it. If you can't do that in mantra it would be possible to render the geometry top faces again but with a shadow catcher material, then in compositing you comp the shadow back on the top faces as you said.

Edited May 12, 2022 by ejr32123