There are some current limitations when using 3ds Max Photometric lights with MAXtoA. Here is a brief list of what is not supported:
• Some light shapes do not support Spherical distribution.
Note that the Physical Scale value in the Exposure Control (Environment and Effects) has an influence over how your 3ds Max and Arnold lights render. You may need to Disable or adjust the Physical Scale to get the intensity you expect.
There is a generic Arnold Light object where you can select the type of light in a combo and the parameters will change dynamically according to the selected type. This can be found under the lights menu in the create tab.
Choose Arnold from the light list
3ds Max scenes (particularly architectural scenes) setup for other rendering engines will not necessarily convert well to MAXtoA. Arnold does not currently support physical units for lights, and a conversion process is not straightforward. You may need to adjust Intensity and Exposure parameters for your lights to match.
As well as honoring the standard 3ds Max light parameters, the Modify Panel will also show the following Arnold parameters:
The shape of the light. Choose from Point, Distant, Spot, Quad, Disc, Cylinder Light, Skydome, Photometric and Mesh.
Types of lights available in MaxtoA
When enabled, the shape of the light is visible in the render as a self-illuminated object.
Per-light scaling for Camera, Transmission, Diffuse, Specular, SSS, Indirect and Volume. Weights scaling the light contribution to each of those components independently. Should be left at 1 to produce physically accurate results.
Light Path Exressions do not currently work in MAXtoA. They are planned for a future release.