<span style="font-family:arial, sans-serif;font-size:13px;border-collapse:collapse"><div>Thanks Lars and Santiago,</div><div>Yes you are right, it doesn't make any sense to have the sun at infinite distance outside the sphere of finite distance. And yes, I'll keep it simple, no optimization with mksource at this point ;o). And a third: Yes - Radiance is tricky, therefore it is so good that this list is active!</div>
<div><br></div><div>However, when changing the 'sphere environment' from sphere to source I cannot display my scene any longer. My source description is</div><div>env_glow source sphereenv</div><div>0 0 </div><div>
4 0 1 0 360</div><div>The simulation approach now follows exactly the one in the Image Based Lighting tutorial from Debevec, p. 31, <a href="http://www.debevec.org/CGAIBL2/ibl-tutorial-cga2002.pdf" target="_blank">http://www.debevec.org/CGAIBL2/ibl-tutorial-cga2002.pdf</a>. I get a white image and the rvu message:</div>
<div><div>rvu: warning - compute error for colorpict "hdr_env"</div><div>rvu: Division by zero</div><div>rvu: Division by zero</div><div><br></div><div>Do you maybe also have tips on how I can solve this?</div>
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Thanks!</div><div>Anne</div><div><span style="font-size:small"><br></span></div></div></span>