Setting Backplate while using OSPRay

Hey all,

I am doing some work using the OSPRay rending tool in PV 5.6, and am having a small issue I was hoping you could help with. When using the pathtracer engine, the image you put as a background is set as an HDRI environmental map (warps it in a sphere around the whole scene). This is good as it is needed for a high-quality rendering, but I was wondering if there was a way to set a backplate image in addition to the HDRI image within the program. Digging through the OSPRay documentation it seems to be implemented in the open source OSPRay code (command is backplate), but I cannot seem to get it work within Paraview.

Thank you for any help you can provide!

The backplate is not hooked up yet.

Someone needs to extend the code in VTK/Rendering/RayTracing (was Rendering/OSPRay) to give the background texture to the path traced ospray renderer and to extend the VTK and ParaView API to add controls that distinguish between that and the environmental light that we use for the environmental background.

Thanks Dave, for anyone else having this issue. One way to work around this that I have discovered is to create a fake “Backplate” by creating a large plane behind what you are analyzing, and assigning it a textured image as an OBJMaterial. This won’t be perfect, but can increase the quality of your rendering compared to an environmental light alone.

I am currently working on OSPRay integration improvements in ParaView.
I am curious about how a backplate can improve the rendering.
Can you provide some screenshots?

Hey Michael,

Good to hear to are working on improvements. Overview of the issues with only using an environmental map as the background

• Can’t use a regular image (Will come out warped and distorted), have to use and HDRI.
• HDRI Environmental maps (that are high quality and warped corrected) are expensive and hard to find. From my testing they need to be at least 8k+ to look good
• If you have the ability to use a backplate, you can control the background of the rendering in much greater detail, and use a traditional image which gives you a lot more options

I mocked up a super simple example to showcase this.

Environmental Map Only (This isn’t a super quality one as it is a quick example, notice the warping and distortion in the background, although the lighting looks good)


Environmental Map with “Fake” backplate image. Notice lighting is correctly defined, and background looks high quality